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platform_system_vold/VolumeManager.cpp
Jeff Sharkey 52f7a91934 Move long-running calls to async with listeners. 
Now that we're using Binder, we can have callers provide explicit
listeners for every request instead of trying to squeeze them all
into unsolicited socket events.

Move benchmarking to be async to avoid blocking other commands for
up to several minutes.  Remove post-trim benchmarking flag, since
benchmarking now requires a separate callback.  Will bring back in
a future CL.

Test: cts-tradefed run commandAndExit cts-dev -m CtsAppSecurityHostTestCases -t android.appsecurity.cts.AdoptableHostTest
Test: adb shell sm fstrim
Bug: 62201209, 13758960
Change-Id: I0f2ebf1ac3b4252ecd6b44303f2887adfdb58e86
2017-09-15 14:18:00 -06:00

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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.
*/
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <fts.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/types.h>
#include <sys/sysmacros.h>
#include <sys/wait.h>
#include <unistd.h>
#include <linux/kdev_t.h>
#define LOG_TAG "Vold"
#include <openssl/md5.h>
#include <android-base/logging.h>
#include <android-base/stringprintf.h>
#include <cutils/fs.h>
#include <cutils/log.h>
#include <selinux/android.h>
#include <sysutils/NetlinkEvent.h>
#include <private/android_filesystem_config.h>
#include "model/EmulatedVolume.h"
#include "model/ObbVolume.h"
#include "VolumeManager.h"
#include "NetlinkManager.h"
#include "ResponseCode.h"
#include "Loop.h"
#include "fs/Ext4.h"
#include "fs/Vfat.h"
#include "Utils.h"
#include "Devmapper.h"
#include "Process.h"
#include "Asec.h"
#include "VoldUtil.h"
#include "cryptfs.h"
#define MASS_STORAGE_FILE_PATH "/sys/class/android_usb/android0/f_mass_storage/lun/file"
#define ROUND_UP_POWER_OF_2(number, po2) (((!!((number) & ((1U << (po2)) - 1))) << (po2))\
+ ((number) & (~((1U << (po2)) - 1))))
using android::base::StringPrintf;
using android::base::unique_fd;
/*
* Path to external storage where *only* root can access ASEC image files
*/
const char *VolumeManager::SEC_ASECDIR_EXT = "/mnt/secure/asec";
/*
* Path to internal storage where *only* root can access ASEC image files
*/
const char *VolumeManager::SEC_ASECDIR_INT = "/data/app-asec";
/*
* Path to where secure containers are mounted
*/
const char *VolumeManager::ASECDIR = "/mnt/asec";
/*
* Path to where OBBs are mounted
*/
const char *VolumeManager::LOOPDIR = "/mnt/obb";
bool VolumeManager::shutting_down = false;
static const char* kPathUserMount = "/mnt/user";
static const char* kPathVirtualDisk = "/data/misc/vold/virtual_disk";
static const char* kPropVirtualDisk = "persist.sys.virtual_disk";
/* 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;
/* writes superblock at end of file or device given by name */
static int writeSuperBlock(const char* name, struct asec_superblock *sb, unsigned int numImgSectors) {
int sbfd = open(name, O_RDWR | O_CLOEXEC);
if (sbfd < 0) {
SLOGE("Failed to open %s for superblock write (%s)", name, strerror(errno));
return -1;
}
if (lseek(sbfd, (numImgSectors * 512), SEEK_SET) < 0) {
SLOGE("Failed to lseek for superblock (%s)", strerror(errno));
close(sbfd);
return -1;
}
if (write(sbfd, sb, sizeof(struct asec_superblock)) != sizeof(struct asec_superblock)) {
SLOGE("Failed to write superblock (%s)", strerror(errno));
close(sbfd);
return -1;
}
close(sbfd);
return 0;
}
static unsigned long adjustSectorNumExt4(unsigned long numSectors) {
// Ext4 started to reserve 2% or 4096 clusters, whichever is smaller for
// preventing costly operations or unexpected ENOSPC error.
// Ext4::format() uses default block size without clustering.
unsigned long clusterSectors = 4096 / 512;
unsigned long reservedSectors = (numSectors * 2)/100 + (numSectors % 50 > 0);
numSectors += reservedSectors > (4096 * clusterSectors) ? (4096 * clusterSectors) : reservedSectors;
return ROUND_UP_POWER_OF_2(numSectors, 3);
}
static unsigned long adjustSectorNumFAT(unsigned long numSectors) {
/*
* Add some headroom
*/
unsigned long fatSize = (((numSectors * 4) / 512) + 1) * 2;
numSectors += fatSize + 2;
/*
* FAT is aligned to 32 kb with 512b sectors.
*/
return ROUND_UP_POWER_OF_2(numSectors, 6);
}
static int setupLoopDevice(char* buffer, size_t len, const char* asecFileName, const char* idHash, bool debug) {
if (Loop::lookupActive(idHash, buffer, len)) {
if (Loop::create(idHash, asecFileName, buffer, len)) {
SLOGE("ASEC loop device creation failed for %s (%s)", asecFileName, strerror(errno));
return -1;
}
if (debug) {
SLOGD("New loop device created at %s", buffer);
}
} else {
if (debug) {
SLOGD("Found active loopback for %s at %s", asecFileName, buffer);
}
}
return 0;
}
static int setupDevMapperDevice(char* buffer, size_t len, const char* loopDevice, const char* asecFileName, const char* key, const char* idHash , unsigned long numImgSectors, bool* createdDMDevice, bool debug) {
if (strcmp(key, "none")) {
if (Devmapper::lookupActive(idHash, buffer, len)) {
if (Devmapper::create(idHash, loopDevice, key, numImgSectors,
buffer, len)) {
SLOGE("ASEC device mapping failed for %s (%s)", asecFileName, strerror(errno));
return -1;
}
if (debug) {
SLOGD("New devmapper instance created at %s", buffer);
}
} else {
if (debug) {
SLOGD("Found active devmapper for %s at %s", asecFileName, buffer);
}
}
*createdDMDevice = true;
} else {
strlcpy(buffer, loopDevice, len);
*createdDMDevice = false;
}
return 0;
}
static void waitForDevMapper(const char *dmDevice) {
/*
* Wait for the device mapper node to be created. Sometimes it takes a
* while. Wait for up to 1 second. We could also inspect incoming uevents,
* but that would take more effort.
*/
int tries = 25;
while (tries--) {
if (!access(dmDevice, F_OK) || errno != ENOENT) {
break;
}
usleep(40 * 1000);
}
}
VolumeManager *VolumeManager::sInstance = NULL;
VolumeManager *VolumeManager::Instance() {
if (!sInstance)
sInstance = new VolumeManager();
return sInstance;
}
VolumeManager::VolumeManager() {
mDebug = false;
mActiveContainers = new AsecIdCollection();
mBroadcaster = NULL;
mUmsSharingCount = 0;
mSavedDirtyRatio = -1;
// set dirty ratio to 0 when UMS is active
mUmsDirtyRatio = 0;
mNextObbId = 0;
}
VolumeManager::~VolumeManager() {
delete mActiveContainers;
}
char *VolumeManager::asecHash(const char *id, char *buffer, size_t len) {
static const char* digits = "0123456789abcdef";
unsigned char sig[MD5_DIGEST_LENGTH];
if (buffer == NULL) {
SLOGE("Destination buffer is NULL");
errno = ESPIPE;
return NULL;
} else if (id == NULL) {
SLOGE("Source buffer is NULL");
errno = ESPIPE;
return NULL;
} else if (len < MD5_ASCII_LENGTH_PLUS_NULL) {
SLOGE("Target hash buffer size < %d bytes (%zu)",
MD5_ASCII_LENGTH_PLUS_NULL, len);
errno = ESPIPE;
return NULL;
}
MD5(reinterpret_cast<const unsigned char*>(id), strlen(id), sig);
char *p = buffer;
for (int i = 0; i < MD5_DIGEST_LENGTH; i++) {
*p++ = digits[sig[i] >> 4];
*p++ = digits[sig[i] & 0x0F];
}
*p = '\0';
return buffer;
}
int VolumeManager::updateVirtualDisk() {
if (property_get_bool(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);
disk->create();
mVirtualDisk = std::shared_ptr<android::vold::Disk>(disk);
mDisks.push_back(mVirtualDisk);
}
} else {
if (mVirtualDisk != nullptr) {
dev_t device = mVirtualDisk->getDevice();
auto i = mDisks.begin();
while (i != mDisks.end()) {
if ((*i)->getDevice() == device) {
(*i)->destroy();
i = mDisks.erase(i);
} else {
++i;
}
}
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() {
// 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(VERBOSE) << "----------------";
LOG(VERBOSE) << "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 = atoi(evt->findParam("MAJOR"));
int minor = atoi(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);
disk->create();
mDisks.push_back(std::shared_ptr<android::vold::Disk>(disk));
break;
}
}
break;
}
case NetlinkEvent::Action::kChange: {
LOG(DEBUG) << "Disk at " << major << ":" << minor << " changed";
for (const auto& disk : mDisks) {
if (disk->getDevice() == device) {
disk->readMetadata();
disk->readPartitions();
}
}
break;
}
case NetlinkEvent::Action::kRemove: {
auto i = mDisks.begin();
while (i != mDisks.end()) {
if ((*i)->getDevice() == device) {
(*i)->destroy();
i = mDisks.erase(i);
} else {
++i;
}
}
break;
}
default: {
LOG(WARNING) << "Unexpected block event action " << (int) evt->getAction();
break;
}
}
}
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 : 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) {
std::string normalizedGuid;
if (android::vold::NormalizeHex(partGuid, normalizedGuid)) {
LOG(WARNING) << "Invalid GUID " << partGuid;
return -1;
}
std::string keyPath = android::vold::BuildKeyPath(normalizedGuid);
if (unlink(keyPath.c_str()) != 0) {
LOG(ERROR) << "Failed to unlink " << keyPath;
return -1;
}
return 0;
}
int VolumeManager::linkPrimary(userid_t userId) {
std::string source(mPrimary->getPath());
if (mPrimary->getType() == android::vold::VolumeBase::Type::kEmulated) {
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) {
SLOGW("Failed to unlink %s: %s", target.c_str(), strerror(errno));
}
}
LOG(DEBUG) << "Linking " << source << " to " << target;
if (TEMP_FAILURE_RETRY(symlink(source.c_str(), target.c_str()))) {
SLOGW("Failed to link %s to %s: %s", source.c_str(), target.c_str(),
strerror(errno));
return -errno;
}
return 0;
}
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) {
// 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);
if (mPrimary) {
linkPrimary(userId);
}
return 0;
}
int VolumeManager::onUserStopped(userid_t userId) {
mStartedUsers.erase(userId);
return 0;
}
int VolumeManager::setPrimary(const std::shared_ptr<android::vold::VolumeBase>& vol) {
mPrimary = vol;
for (userid_t userId : mStartedUsers) {
linkPrimary(userId);
}
return 0;
}
static int unmount_tree(const char* path) {
size_t path_len = strlen(path);
FILE* fp = setmntent("/proc/mounts", "r");
if (fp == NULL) {
ALOGE("Error opening /proc/mounts: %s", strerror(errno));
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) {
if (strncmp(mentry->mnt_dir, path, path_len) == 0) {
toUnmount.push_front(std::string(mentry->mnt_dir));
}
}
endmntent(fp);
for (const auto& path : toUnmount) {
if (umount2(path.c_str(), MNT_DETACH)) {
ALOGW("Failed to unmount %s: %s", path.c_str(), strerror(errno));
}
}
return 0;
}
int VolumeManager::remountUid(uid_t uid, const std::string& mode) {
LOG(DEBUG) << "Remounting " << uid << " as mode " << mode;
DIR* dir;
struct dirent* de;
char rootName[PATH_MAX];
char pidName[PATH_MAX];
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::SaneReadLinkAt(dirfd(dir), "1/ns/mnt", rootName, PATH_MAX) == -1) {
PLOG(ERROR) << "Failed to readlink";
closedir(dir);
return -1;
}
// Poke through all running PIDs look for apps running as UID
while ((de = readdir(dir))) {
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::SaneReadLinkAt(pidFd, "ns/mnt", pidName, PATH_MAX) == -1) {
PLOG(WARNING) << "Failed to read namespace for " << de->d_name;
goto next;
}
if (!strcmp(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);
}
unmount_tree("/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();
return 0;
}
// Can be called twice (sequentially) during shutdown. should be safe for that.
int VolumeManager::shutdown() {
if (mInternalEmulated == nullptr) {
return 0; // already shutdown
}
shutting_down = true;
mInternalEmulated->destroy();
mInternalEmulated = nullptr;
for (const auto& disk : mDisks) {
disk->destroy();
}
mDisks.clear();
shutting_down = false;
return 0;
}
int VolumeManager::unmountAll() {
std::lock_guard<std::mutex> lock(mLock);
// First, try gracefully unmounting all known devices
if (mInternalEmulated != nullptr) {
mInternalEmulated->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", "r");
if (fp == NULL) {
SLOGE("Error opening /proc/mounts: %s", strerror(errno));
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) {
if (strncmp(mentry->mnt_dir, "/mnt/", 5) == 0
|| strncmp(mentry->mnt_dir, "/storage/", 9) == 0) {
toUnmount.push_front(std::string(mentry->mnt_dir));
}
}
endmntent(fp);
for (const auto& path : toUnmount) {
LOG(DEBUG) << "Tearing down stale mount " << path;
android::vold::ForceUnmount(path);
}
return 0;
}
int VolumeManager::getObbMountPath(const char *sourceFile, char *mountPath, int mountPathLen) {
char idHash[33];
if (!asecHash(sourceFile, idHash, sizeof(idHash))) {
SLOGE("Hash of '%s' failed (%s)", sourceFile, strerror(errno));
return -1;
}
memset(mountPath, 0, mountPathLen);
int written = snprintf(mountPath, mountPathLen, "%s/%s", VolumeManager::LOOPDIR, idHash);
if ((written < 0) || (written >= mountPathLen)) {
errno = EINVAL;
return -1;
}
if (access(mountPath, F_OK)) {
errno = ENOENT;
return -1;
}
return 0;
}
int VolumeManager::getAsecMountPath(const char *id, char *buffer, int maxlen) {
char asecFileName[255];
if (!isLegalAsecId(id)) {
SLOGE("getAsecMountPath: Invalid asec id \"%s\"", id);
errno = EINVAL;
return -1;
}
if (findAsec(id, asecFileName, sizeof(asecFileName))) {
SLOGE("Couldn't find ASEC %s", id);
return -1;
}
memset(buffer, 0, maxlen);
if (access(asecFileName, F_OK)) {
errno = ENOENT;
return -1;
}
int written = snprintf(buffer, maxlen, "%s/%s", VolumeManager::ASECDIR, id);
if ((written < 0) || (written >= maxlen)) {
SLOGE("getAsecMountPath failed for %s: couldn't construct path in buffer", id);
errno = EINVAL;
return -1;
}
return 0;
}
int VolumeManager::getAsecFilesystemPath(const char *id, char *buffer, int maxlen) {
char asecFileName[255];
if (!isLegalAsecId(id)) {
SLOGE("getAsecFilesystemPath: Invalid asec id \"%s\"", id);
errno = EINVAL;
return -1;
}
if (findAsec(id, asecFileName, sizeof(asecFileName))) {
SLOGE("Couldn't find ASEC %s", id);
return -1;
}
memset(buffer, 0, maxlen);
if (access(asecFileName, F_OK)) {
errno = ENOENT;
return -1;
}
int written = snprintf(buffer, maxlen, "%s", asecFileName);
if ((written < 0) || (written >= maxlen)) {
errno = EINVAL;
return -1;
}
return 0;
}
int VolumeManager::createAsec(const char *id, unsigned long numSectors, const char *fstype,
const char *key, const int ownerUid, bool isExternal) {
struct asec_superblock sb;
memset(&sb, 0, sizeof(sb));
if (!isLegalAsecId(id)) {
SLOGE("createAsec: Invalid asec id \"%s\"", id);
errno = EINVAL;
return -1;
}
const bool wantFilesystem = strcmp(fstype, "none");
bool usingExt4 = false;
if (wantFilesystem) {
usingExt4 = !strcmp(fstype, "ext4");
if (usingExt4) {
sb.c_opts |= ASEC_SB_C_OPTS_EXT4;
} else if (strcmp(fstype, "fat")) {
SLOGE("Invalid filesystem type %s", fstype);
errno = EINVAL;
return -1;
}
}
sb.magic = ASEC_SB_MAGIC;
sb.ver = ASEC_SB_VER;
if (numSectors < ((1024*1024)/512)) {
SLOGE("Invalid container size specified (%lu sectors)", numSectors);
errno = EINVAL;
return -1;
}
char asecFileName[255];
if (!findAsec(id, asecFileName, sizeof(asecFileName))) {
SLOGE("ASEC file '%s' currently exists - destroy it first! (%s)",
asecFileName, strerror(errno));
errno = EADDRINUSE;
return -1;
}
const char *asecDir = isExternal ? VolumeManager::SEC_ASECDIR_EXT : VolumeManager::SEC_ASECDIR_INT;
int written = snprintf(asecFileName, sizeof(asecFileName), "%s/%s.asec", asecDir, id);
if ((written < 0) || (size_t(written) >= sizeof(asecFileName))) {
errno = EINVAL;
return -1;
}
if (!access(asecFileName, F_OK)) {
SLOGE("ASEC file '%s' currently exists - destroy it first! (%s)",
asecFileName, strerror(errno));
errno = EADDRINUSE;
return -1;
}
unsigned long numImgSectors;
if (usingExt4)
numImgSectors = adjustSectorNumExt4(numSectors);
else
numImgSectors = adjustSectorNumFAT(numSectors);
// Add +1 for our superblock which is at the end
if (Loop::createImageFile(asecFileName, numImgSectors + 1)) {
SLOGE("ASEC image file creation failed (%s)", strerror(errno));
return -1;
}
char idHash[33];
if (!asecHash(id, idHash, sizeof(idHash))) {
SLOGE("Hash of '%s' failed (%s)", id, strerror(errno));
unlink(asecFileName);
return -1;
}
char loopDevice[255];
if (Loop::create(idHash, asecFileName, loopDevice, sizeof(loopDevice))) {
SLOGE("ASEC loop device creation failed (%s)", strerror(errno));
unlink(asecFileName);
return -1;
}
char dmDevice[255];
bool cleanupDm = false;
if (strcmp(key, "none")) {
// XXX: This is all we support for now
sb.c_cipher = ASEC_SB_C_CIPHER_TWOFISH;
if (Devmapper::create(idHash, loopDevice, key, numImgSectors, dmDevice,
sizeof(dmDevice))) {
SLOGE("ASEC device mapping failed (%s)", strerror(errno));
Loop::destroyByDevice(loopDevice);
unlink(asecFileName);
return -1;
}
cleanupDm = true;
} else {
sb.c_cipher = ASEC_SB_C_CIPHER_NONE;
strlcpy(dmDevice, loopDevice, sizeof(dmDevice));
}
/*
* Drop down the superblock at the end of the file
*/
if (writeSuperBlock(loopDevice, &sb, numImgSectors)) {
if (cleanupDm) {
Devmapper::destroy(idHash);
}
Loop::destroyByDevice(loopDevice);
unlink(asecFileName);
return -1;
}
if (wantFilesystem) {
int formatStatus;
char mountPoint[255];
int written = snprintf(mountPoint, sizeof(mountPoint), "%s/%s", VolumeManager::ASECDIR, id);
if ((written < 0) || (size_t(written) >= sizeof(mountPoint))) {
SLOGE("ASEC fs format failed: couldn't construct mountPoint");
if (cleanupDm) {
Devmapper::destroy(idHash);
}
Loop::destroyByDevice(loopDevice);
unlink(asecFileName);
return -1;
}
if (usingExt4) {
formatStatus = android::vold::ext4::Format(dmDevice, numImgSectors, mountPoint);
} else {
formatStatus = android::vold::vfat::Format(dmDevice, numImgSectors);
}
if (formatStatus < 0) {
SLOGE("ASEC fs format failed (%s)", strerror(errno));
if (cleanupDm) {
Devmapper::destroy(idHash);
}
Loop::destroyByDevice(loopDevice);
unlink(asecFileName);
return -1;
}
if (mkdir(mountPoint, 0000)) {
if (errno != EEXIST) {
SLOGE("Mountpoint creation failed (%s)", strerror(errno));
if (cleanupDm) {
Devmapper::destroy(idHash);
}
Loop::destroyByDevice(loopDevice);
unlink(asecFileName);
return -1;
}
}
int mountStatus;
if (usingExt4) {
mountStatus = android::vold::ext4::Mount(dmDevice, mountPoint,
false, false, false);
} else {
mountStatus = android::vold::vfat::Mount(dmDevice, mountPoint,
false, false, false, ownerUid, 0, 0000, false);
}
if (mountStatus) {
SLOGE("ASEC FAT mount failed (%s)", strerror(errno));
if (cleanupDm) {
Devmapper::destroy(idHash);
}
Loop::destroyByDevice(loopDevice);
unlink(asecFileName);
return -1;
}
if (usingExt4) {
int dirfd = open(mountPoint, O_DIRECTORY | O_CLOEXEC);
if (dirfd >= 0) {
if (fchown(dirfd, ownerUid, AID_SYSTEM)
|| fchmod(dirfd, S_IRUSR | S_IWUSR | S_IXUSR | S_ISGID | S_IRGRP | S_IXGRP)) {
SLOGI("Cannot chown/chmod new ASEC mount point %s", mountPoint);
}
close(dirfd);
}
}
} else {
SLOGI("Created raw secure container %s (no filesystem)", id);
}
mActiveContainers->push_back(new ContainerData(strdup(id), ASEC));
return 0;
}
int VolumeManager::resizeAsec(const char *id, unsigned long numSectors, const char *key) {
char asecFileName[255];
char mountPoint[255];
bool cleanupDm = false;
if (!isLegalAsecId(id)) {
SLOGE("resizeAsec: Invalid asec id \"%s\"", id);
errno = EINVAL;
return -1;
}
if (findAsec(id, asecFileName, sizeof(asecFileName))) {
SLOGE("Couldn't find ASEC %s", id);
return -1;
}
int written = snprintf(mountPoint, sizeof(mountPoint), "%s/%s", VolumeManager::ASECDIR, id);
if ((written < 0) || (size_t(written) >= sizeof(mountPoint))) {
SLOGE("ASEC resize failed for %s: couldn't construct mountpoint", id);
return -1;
}
if (isMountpointMounted(mountPoint)) {
SLOGE("ASEC %s mounted. Unmount before resizing", id);
errno = EBUSY;
return -1;
}
struct asec_superblock sb;
int fd;
unsigned long oldNumSec = 0;
if ((fd = open(asecFileName, O_RDONLY | O_CLOEXEC)) < 0) {
SLOGE("Failed to open ASEC file (%s)", strerror(errno));
return -1;
}
struct stat info;
if (fstat(fd, &info) < 0) {
SLOGE("Failed to get file size (%s)", strerror(errno));
close(fd);
return -1;
}
oldNumSec = info.st_size / 512;
/*
* Try to read superblock.
*/
memset(&sb, 0, sizeof(struct asec_superblock));
if (lseek(fd, ((oldNumSec - 1) * 512), SEEK_SET) < 0) {
SLOGE("lseek failed (%s)", strerror(errno));
close(fd);
return -1;
}
if (read(fd, &sb, sizeof(struct asec_superblock)) != sizeof(struct asec_superblock)) {
SLOGE("superblock read failed (%s)", strerror(errno));
close(fd);
return -1;
}
close(fd);
if (mDebug) {
SLOGD("Container sb magic/ver (%.8x/%.2x)", sb.magic, sb.ver);
}
if (sb.magic != ASEC_SB_MAGIC || sb.ver != ASEC_SB_VER) {
SLOGE("Bad container magic/version (%.8x/%.2x)", sb.magic, sb.ver);
errno = EMEDIUMTYPE;
return -1;
}
unsigned long numImgSectors;
if (!(sb.c_opts & ASEC_SB_C_OPTS_EXT4)) {
SLOGE("Only ext4 partitions are supported for resize");
errno = EINVAL;
return -1;
} else {
numImgSectors = adjustSectorNumExt4(numSectors);
}
/*
* add one block for the superblock
*/
SLOGD("Resizing from %lu sectors to %lu sectors", oldNumSec, numImgSectors + 1);
if (oldNumSec == numImgSectors + 1) {
SLOGW("Size unchanged; ignoring resize request");
return 0;
} else if (oldNumSec > numImgSectors + 1) {
SLOGE("Only growing is currently supported.");
close(fd);
return -1;
}
if (Loop::resizeImageFile(asecFileName, numImgSectors + 1)) {
SLOGE("Resize of ASEC image file failed. Could not resize %s", id);
return -1;
}
/*
* Drop down a copy of the superblock at the end of the file
*/
if (writeSuperBlock(asecFileName, &sb, numImgSectors))
goto fail;
char idHash[33];
if (!asecHash(id, idHash, sizeof(idHash))) {
SLOGE("Hash of '%s' failed (%s)", id, strerror(errno));
goto fail;
}
char loopDevice[255];
if (setupLoopDevice(loopDevice, sizeof(loopDevice), asecFileName, idHash, mDebug))
goto fail;
char dmDevice[255];
if (setupDevMapperDevice(dmDevice, sizeof(dmDevice), loopDevice, asecFileName, key, idHash, numImgSectors, &cleanupDm, mDebug)) {
Loop::destroyByDevice(loopDevice);
goto fail;
}
/*
* Wait for the device mapper node to be created.
*/
waitForDevMapper(dmDevice);
if (android::vold::ext4::Resize(dmDevice, numImgSectors)) {
SLOGE("Unable to resize %s (%s)", id, strerror(errno));
if (cleanupDm) {
Devmapper::destroy(idHash);
}
Loop::destroyByDevice(loopDevice);
goto fail;
}
return 0;
fail:
Loop::resizeImageFile(asecFileName, oldNumSec);
return -1;
}
int VolumeManager::finalizeAsec(const char *id) {
char asecFileName[255];
char loopDevice[255];
char mountPoint[255];
if (!isLegalAsecId(id)) {
SLOGE("finalizeAsec: Invalid asec id \"%s\"", id);
errno = EINVAL;
return -1;
}
if (findAsec(id, asecFileName, sizeof(asecFileName))) {
SLOGE("Couldn't find ASEC %s", id);
return -1;
}
char idHash[33];
if (!asecHash(id, idHash, sizeof(idHash))) {
SLOGE("Hash of '%s' failed (%s)", id, strerror(errno));
return -1;
}
if (Loop::lookupActive(idHash, loopDevice, sizeof(loopDevice))) {
SLOGE("Unable to finalize %s (%s)", id, strerror(errno));
return -1;
}
unsigned long nr_sec = 0;
struct asec_superblock sb;
if (Loop::lookupInfo(loopDevice, &sb, &nr_sec)) {
return -1;
}
int written = snprintf(mountPoint, sizeof(mountPoint), "%s/%s", VolumeManager::ASECDIR, id);
if ((written < 0) || (size_t(written) >= sizeof(mountPoint))) {
SLOGE("ASEC finalize failed: couldn't construct mountPoint");
return -1;
}
int result = 0;
if (sb.c_opts & ASEC_SB_C_OPTS_EXT4) {
result = android::vold::ext4::Mount(loopDevice, mountPoint,
true, true, true);
} else {
result = android::vold::vfat::Mount(loopDevice, mountPoint,
true, true, true, 0, 0, 0227, false);
}
if (result) {
SLOGE("ASEC finalize mount failed (%s)", strerror(errno));
return -1;
}
if (mDebug) {
SLOGD("ASEC %s finalized", id);
}
return 0;
}
int VolumeManager::fixupAsecPermissions(const char *id, gid_t gid, const char* filename) {
char asecFileName[255];
char loopDevice[255];
char mountPoint[255];
if (gid < AID_APP) {
SLOGE("Group ID is not in application range");
return -1;
}
if (!isLegalAsecId(id)) {
SLOGE("fixupAsecPermissions: Invalid asec id \"%s\"", id);
errno = EINVAL;
return -1;
}
if (findAsec(id, asecFileName, sizeof(asecFileName))) {
SLOGE("Couldn't find ASEC %s", id);
return -1;
}
char idHash[33];
if (!asecHash(id, idHash, sizeof(idHash))) {
SLOGE("Hash of '%s' failed (%s)", id, strerror(errno));
return -1;
}
if (Loop::lookupActive(idHash, loopDevice, sizeof(loopDevice))) {
SLOGE("Unable fix permissions during lookup on %s (%s)", id, strerror(errno));
return -1;
}
unsigned long nr_sec = 0;
struct asec_superblock sb;
if (Loop::lookupInfo(loopDevice, &sb, &nr_sec)) {
return -1;
}
int written = snprintf(mountPoint, sizeof(mountPoint), "%s/%s", VolumeManager::ASECDIR, id);
if ((written < 0) || (size_t(written) >= sizeof(mountPoint))) {
SLOGE("Unable remount to fix permissions for %s: couldn't construct mountpoint", id);
return -1;
}
int result = 0;
if ((sb.c_opts & ASEC_SB_C_OPTS_EXT4) == 0) {
return 0;
}
int ret = android::vold::ext4::Mount(loopDevice, mountPoint,
false /* read-only */,
true /* remount */,
false /* executable */);
if (ret) {
SLOGE("Unable remount to fix permissions for %s (%s)", id, strerror(errno));
return -1;
}
char *paths[] = { mountPoint, NULL };
FTS *fts = fts_open(paths, FTS_PHYSICAL | FTS_NOCHDIR | FTS_XDEV, NULL);
if (fts) {
// Traverse the entire hierarchy and chown to system UID.
for (FTSENT *ftsent = fts_read(fts); ftsent != NULL; ftsent = fts_read(fts)) {
// We don't care about the lost+found directory.
if (!strcmp(ftsent->fts_name, "lost+found")) {
continue;
}
/*
* There can only be one file marked as private right now.
* This should be more robust, but it satisfies the requirements
* we have for right now.
*/
const bool privateFile = !strcmp(ftsent->fts_name, filename);
int fd = open(ftsent->fts_accpath, O_NOFOLLOW | O_CLOEXEC);
if (fd < 0) {
SLOGE("Couldn't open file %s: %s", ftsent->fts_accpath, strerror(errno));
result = -1;
continue;
}
result |= fchown(fd, AID_SYSTEM, privateFile? gid : AID_SYSTEM);
if (ftsent->fts_info & FTS_D) {
result |= fchmod(fd, 0755);
} else if (ftsent->fts_info & FTS_F) {
result |= fchmod(fd, privateFile ? 0640 : 0644);
}
if (selinux_android_restorecon(ftsent->fts_path, 0) < 0) {
SLOGE("restorecon failed for %s: %s\n", ftsent->fts_path, strerror(errno));
result |= -1;
}
close(fd);
}
fts_close(fts);
// Finally make the directory readable by everyone.
int dirfd = open(mountPoint, O_DIRECTORY | O_CLOEXEC);
if (dirfd < 0 || fchmod(dirfd, 0755)) {
SLOGE("Couldn't change owner of existing directory %s: %s", mountPoint, strerror(errno));
result |= -1;
}
close(dirfd);
} else {
result |= -1;
}
result |= android::vold::ext4::Mount(loopDevice, mountPoint,
true /* read-only */,
true /* remount */,
true /* execute */);
if (result) {
SLOGE("ASEC fix permissions failed (%s)", strerror(errno));
return -1;
}
if (mDebug) {
SLOGD("ASEC %s permissions fixed", id);
}
return 0;
}
int VolumeManager::renameAsec(const char *id1, const char *id2) {
char asecFilename1[255];
char *asecFilename2;
char mountPoint[255];
const char *dir;
if (!isLegalAsecId(id1)) {
SLOGE("renameAsec: Invalid asec id1 \"%s\"", id1);
errno = EINVAL;
return -1;
}
if (!isLegalAsecId(id2)) {
SLOGE("renameAsec: Invalid asec id2 \"%s\"", id2);
errno = EINVAL;
return -1;
}
if (findAsec(id1, asecFilename1, sizeof(asecFilename1), &dir)) {
SLOGE("Couldn't find ASEC %s", id1);
return -1;
}
asprintf(&asecFilename2, "%s/%s.asec", dir, id2);
int written = snprintf(mountPoint, sizeof(mountPoint), "%s/%s", VolumeManager::ASECDIR, id1);
if ((written < 0) || (size_t(written) >= sizeof(mountPoint))) {
SLOGE("Rename failed: couldn't construct mountpoint");
goto out_err;
}
if (isMountpointMounted(mountPoint)) {
SLOGW("Rename attempt when src mounted");
errno = EBUSY;
goto out_err;
}
written = snprintf(mountPoint, sizeof(mountPoint), "%s/%s", VolumeManager::ASECDIR, id2);
if ((written < 0) || (size_t(written) >= sizeof(mountPoint))) {
SLOGE("Rename failed: couldn't construct mountpoint2");
goto out_err;
}
if (isMountpointMounted(mountPoint)) {
SLOGW("Rename attempt when dst mounted");
errno = EBUSY;
goto out_err;
}
if (!access(asecFilename2, F_OK)) {
SLOGE("Rename attempt when dst exists");
errno = EADDRINUSE;
goto out_err;
}
if (rename(asecFilename1, asecFilename2)) {
SLOGE("Rename of '%s' to '%s' failed (%s)", asecFilename1, asecFilename2, strerror(errno));
goto out_err;
}
free(asecFilename2);
return 0;
out_err:
free(asecFilename2);
return -1;
}
#define UNMOUNT_RETRIES 5
#define UNMOUNT_SLEEP_BETWEEN_RETRY_MS (1000 * 1000)
int VolumeManager::unmountAsec(const char *id, bool force) {
char asecFileName[255];
char mountPoint[255];
if (!isLegalAsecId(id)) {
SLOGE("unmountAsec: Invalid asec id \"%s\"", id);
errno = EINVAL;
return -1;
}
if (findAsec(id, asecFileName, sizeof(asecFileName))) {
SLOGE("Couldn't find ASEC %s", id);
return -1;
}
int written = snprintf(mountPoint, sizeof(mountPoint), "%s/%s", VolumeManager::ASECDIR, id);
if ((written < 0) || (size_t(written) >= sizeof(mountPoint))) {
SLOGE("ASEC unmount failed for %s: couldn't construct mountpoint", id);
return -1;
}
char idHash[33];
if (!asecHash(id, idHash, sizeof(idHash))) {
SLOGE("Hash of '%s' failed (%s)", id, strerror(errno));
return -1;
}
return unmountLoopImage(id, idHash, asecFileName, mountPoint, force);
}
int VolumeManager::unmountObb(const char *fileName, bool force) {
char mountPoint[255];
char idHash[33];
if (!asecHash(fileName, idHash, sizeof(idHash))) {
SLOGE("Hash of '%s' failed (%s)", fileName, strerror(errno));
return -1;
}
int written = snprintf(mountPoint, sizeof(mountPoint), "%s/%s", VolumeManager::LOOPDIR, idHash);
if ((written < 0) || (size_t(written) >= sizeof(mountPoint))) {
SLOGE("OBB unmount failed for %s: couldn't construct mountpoint", fileName);
return -1;
}
return unmountLoopImage(fileName, idHash, fileName, mountPoint, force);
}
int VolumeManager::unmountLoopImage(const char *id, const char *idHash,
const char *fileName, const char *mountPoint, bool force) {
if (!isMountpointMounted(mountPoint)) {
SLOGE("Unmount request for %s when not mounted", id);
errno = ENOENT;
return -1;
}
int i, rc;
for (i = 1; i <= UNMOUNT_RETRIES; i++) {
rc = umount(mountPoint);
if (!rc) {
break;
}
if (rc && (errno == EINVAL || errno == ENOENT)) {
SLOGI("Container %s unmounted OK", id);
rc = 0;
break;
}
SLOGW("%s unmount attempt %d failed (%s)",
id, i, strerror(errno));
int signal = 0; // default is to just complain
if (force) {
if (i > (UNMOUNT_RETRIES - 2))
signal = SIGKILL;
else if (i > (UNMOUNT_RETRIES - 3))
signal = SIGTERM;
}
Process::killProcessesWithOpenFiles(mountPoint, signal);
usleep(UNMOUNT_SLEEP_BETWEEN_RETRY_MS);
}
if (rc) {
errno = EBUSY;
SLOGE("Failed to unmount container %s (%s)", id, strerror(errno));
return -1;
}
int retries = 10;
while(retries--) {
if (!rmdir(mountPoint)) {
break;
}
SLOGW("Failed to rmdir %s (%s)", mountPoint, strerror(errno));
usleep(UNMOUNT_SLEEP_BETWEEN_RETRY_MS);
}
if (!retries) {
SLOGE("Timed out trying to rmdir %s (%s)", mountPoint, strerror(errno));
}
for (i=1; i <= UNMOUNT_RETRIES; i++) {
if (Devmapper::destroy(idHash) && errno != ENXIO) {
SLOGE("Failed to destroy devmapper instance (%s)", strerror(errno));
usleep(UNMOUNT_SLEEP_BETWEEN_RETRY_MS);
continue;
} else {
break;
}
}
char loopDevice[255];
if (!Loop::lookupActive(idHash, loopDevice, sizeof(loopDevice))) {
Loop::destroyByDevice(loopDevice);
} else {
SLOGW("Failed to find loop device for {%s} (%s)", fileName, strerror(errno));
}
AsecIdCollection::iterator it;
for (it = mActiveContainers->begin(); it != mActiveContainers->end(); ++it) {
ContainerData* cd = *it;
if (!strcmp(cd->id, id)) {
free(*it);
mActiveContainers->erase(it);
break;
}
}
if (it == mActiveContainers->end()) {
SLOGW("mActiveContainers is inconsistent!");
}
return 0;
}
int VolumeManager::destroyAsec(const char *id, bool force) {
char asecFileName[255];
char mountPoint[255];
if (!isLegalAsecId(id)) {
SLOGE("destroyAsec: Invalid asec id \"%s\"", id);
errno = EINVAL;
return -1;
}
if (findAsec(id, asecFileName, sizeof(asecFileName))) {
SLOGE("Couldn't find ASEC %s", id);
return -1;
}
int written = snprintf(mountPoint, sizeof(mountPoint), "%s/%s", VolumeManager::ASECDIR, id);
if ((written < 0) || (size_t(written) >= sizeof(mountPoint))) {
SLOGE("ASEC destroy failed for %s: couldn't construct mountpoint", id);
return -1;
}
if (isMountpointMounted(mountPoint)) {
if (mDebug) {
SLOGD("Unmounting container before destroy");
}
if (unmountAsec(id, force)) {
SLOGE("Failed to unmount asec %s for destroy (%s)", id, strerror(errno));
return -1;
}
}
if (unlink(asecFileName)) {
SLOGE("Failed to unlink asec '%s' (%s)", asecFileName, strerror(errno));
return -1;
}
if (mDebug) {
SLOGD("ASEC %s destroyed", id);
}
return 0;
}
/*
* Legal ASEC ids consist of alphanumeric characters, '-',
* '_', or '.'. ".." is not allowed. The first or last character
* of the ASEC id cannot be '.' (dot).
*/
bool VolumeManager::isLegalAsecId(const char *id) const {
size_t i;
size_t len = strlen(id);
if (len == 0) {
return false;
}
if ((id[0] == '.') || (id[len - 1] == '.')) {
return false;
}
for (i = 0; i < len; i++) {
if (id[i] == '.') {
// i=0 is guaranteed never to have a dot. See above.
if (id[i-1] == '.') return false;
continue;
}
if (id[i] == '_' || id[i] == '-') continue;
if (id[i] >= 'a' && id[i] <= 'z') continue;
if (id[i] >= 'A' && id[i] <= 'Z') continue;
if (id[i] >= '0' && id[i] <= '9') continue;
return false;
}
return true;
}
bool VolumeManager::isAsecInDirectory(const char *dir, const char *asecName) const {
int dirfd = open(dir, O_DIRECTORY | O_CLOEXEC);
if (dirfd < 0) {
SLOGE("Couldn't open internal ASEC dir (%s)", strerror(errno));
return false;
}
struct stat sb;
bool ret = (fstatat(dirfd, asecName, &sb, AT_SYMLINK_NOFOLLOW) == 0)
&& S_ISREG(sb.st_mode);
close(dirfd);
return ret;
}
int VolumeManager::findAsec(const char *id, char *asecPath, size_t asecPathLen,
const char **directory) const {
char *asecName;
if (!isLegalAsecId(id)) {
SLOGE("findAsec: Invalid asec id \"%s\"", id);
errno = EINVAL;
return -1;
}
if (asprintf(&asecName, "%s.asec", id) < 0) {
SLOGE("Couldn't allocate string to write ASEC name");
return -1;
}
const char *dir;
if (isAsecInDirectory(VolumeManager::SEC_ASECDIR_INT, asecName)) {
dir = VolumeManager::SEC_ASECDIR_INT;
} else if (isAsecInDirectory(VolumeManager::SEC_ASECDIR_EXT, asecName)) {
dir = VolumeManager::SEC_ASECDIR_EXT;
} else {
free(asecName);
return -1;
}
if (directory != NULL) {
*directory = dir;
}
if (asecPath != NULL) {
int written = snprintf(asecPath, asecPathLen, "%s/%s", dir, asecName);
if ((written < 0) || (size_t(written) >= asecPathLen)) {
SLOGE("findAsec failed for %s: couldn't construct ASEC path", id);
free(asecName);
return -1;
}
}
free(asecName);
return 0;
}
int VolumeManager::mountAsec(const char *id, const char *key, int ownerUid, bool readOnly) {
char asecFileName[255];
char mountPoint[255];
if (!isLegalAsecId(id)) {
SLOGE("mountAsec: Invalid asec id \"%s\"", id);
errno = EINVAL;
return -1;
}
if (findAsec(id, asecFileName, sizeof(asecFileName))) {
SLOGE("Couldn't find ASEC %s", id);
return -1;
}
int written = snprintf(mountPoint, sizeof(mountPoint), "%s/%s", VolumeManager::ASECDIR, id);
if ((written < 0) || (size_t(written) >= sizeof(mountPoint))) {
SLOGE("ASEC mount failed for %s: couldn't construct mountpoint", id);
return -1;
}
if (isMountpointMounted(mountPoint)) {
SLOGE("ASEC %s already mounted", id);
errno = EBUSY;
return -1;
}
char idHash[33];
if (!asecHash(id, idHash, sizeof(idHash))) {
SLOGE("Hash of '%s' failed (%s)", id, strerror(errno));
return -1;
}
char loopDevice[255];
if (setupLoopDevice(loopDevice, sizeof(loopDevice), asecFileName, idHash, mDebug))
return -1;
char dmDevice[255];
bool cleanupDm = false;
unsigned long nr_sec = 0;
struct asec_superblock sb;
if (Loop::lookupInfo(loopDevice, &sb, &nr_sec)) {
return -1;
}
if (mDebug) {
SLOGD("Container sb magic/ver (%.8x/%.2x)", sb.magic, sb.ver);
}
if (sb.magic != ASEC_SB_MAGIC || sb.ver != ASEC_SB_VER) {
SLOGE("Bad container magic/version (%.8x/%.2x)", sb.magic, sb.ver);
Loop::destroyByDevice(loopDevice);
errno = EMEDIUMTYPE;
return -1;
}
nr_sec--; // We don't want the devmapping to extend onto our superblock
if (setupDevMapperDevice(dmDevice, sizeof(dmDevice), loopDevice, asecFileName, key, idHash , nr_sec, &cleanupDm, mDebug)) {
Loop::destroyByDevice(loopDevice);
return -1;
}
if (mkdir(mountPoint, 0000)) {
if (errno != EEXIST) {
SLOGE("Mountpoint creation failed (%s)", strerror(errno));
if (cleanupDm) {
Devmapper::destroy(idHash);
}
Loop::destroyByDevice(loopDevice);
return -1;
}
}
/*
* Wait for the device mapper node to be created.
*/
waitForDevMapper(dmDevice);
int result;
if (sb.c_opts & ASEC_SB_C_OPTS_EXT4) {
result = android::vold::ext4::Mount(dmDevice, mountPoint,
readOnly, false, readOnly);
} else {
result = android::vold::vfat::Mount(dmDevice, mountPoint,
readOnly, false, readOnly, ownerUid, 0, 0222, false);
}
if (result) {
SLOGE("ASEC mount failed (%s)", strerror(errno));
if (cleanupDm) {
Devmapper::destroy(idHash);
}
Loop::destroyByDevice(loopDevice);
return -1;
}
mActiveContainers->push_back(new ContainerData(strdup(id), ASEC));
if (mDebug) {
SLOGD("ASEC %s mounted", id);
}
return 0;
}
/**
* Mounts an image file <code>img</code>.
*/
int VolumeManager::mountObb(const char *img, const char *key, int ownerGid) {
char mountPoint[255];
char idHash[33];
if (!asecHash(img, idHash, sizeof(idHash))) {
SLOGE("Hash of '%s' failed (%s)", img, strerror(errno));
return -1;
}
int written = snprintf(mountPoint, sizeof(mountPoint), "%s/%s", VolumeManager::LOOPDIR, idHash);
if ((written < 0) || (size_t(written) >= sizeof(mountPoint))) {
SLOGE("OBB mount failed for %s: couldn't construct mountpoint", img);
return -1;
}
if (isMountpointMounted(mountPoint)) {
SLOGE("Image %s already mounted", img);
errno = EBUSY;
return -1;
}
char loopDevice[255];
if (setupLoopDevice(loopDevice, sizeof(loopDevice), img, idHash, mDebug))
return -1;
char dmDevice[255];
bool cleanupDm = false;
int fd;
unsigned long nr_sec = 0;
if ((fd = open(loopDevice, O_RDWR | O_CLOEXEC)) < 0) {
SLOGE("Failed to open loopdevice (%s)", strerror(errno));
Loop::destroyByDevice(loopDevice);
return -1;
}
get_blkdev_size(fd, &nr_sec);
if (nr_sec == 0) {
SLOGE("Failed to get loop size (%s)", strerror(errno));
Loop::destroyByDevice(loopDevice);
close(fd);
return -1;
}
close(fd);
if (setupDevMapperDevice(dmDevice, sizeof(loopDevice), loopDevice, img,key, idHash, nr_sec, &cleanupDm, mDebug)) {
Loop::destroyByDevice(loopDevice);
return -1;
}
if (mkdir(mountPoint, 0755)) {
if (errno != EEXIST) {
SLOGE("Mountpoint creation failed (%s)", strerror(errno));
if (cleanupDm) {
Devmapper::destroy(idHash);
}
Loop::destroyByDevice(loopDevice);
return -1;
}
}
/*
* Wait for the device mapper node to be created.
*/
waitForDevMapper(dmDevice);
if (android::vold::vfat::Mount(dmDevice, mountPoint,
true, false, true, 0, ownerGid, 0227, false)) {
SLOGE("Image mount failed (%s)", strerror(errno));
if (cleanupDm) {
Devmapper::destroy(idHash);
}
Loop::destroyByDevice(loopDevice);
return -1;
}
mActiveContainers->push_back(new ContainerData(strdup(img), OBB));
if (mDebug) {
SLOGD("Image %s mounted", img);
}
return 0;
}
int VolumeManager::listMountedObbs(SocketClient* cli) {
FILE *fp = setmntent("/proc/mounts", "r");
if (fp == NULL) {
SLOGE("Error opening /proc/mounts (%s)", strerror(errno));
return -1;
}
// Create a string to compare against that has a trailing slash
int loopDirLen = strlen(VolumeManager::LOOPDIR);
char loopDir[loopDirLen + 2];
strlcpy(loopDir, VolumeManager::LOOPDIR, sizeof(loopDir));
loopDir[loopDirLen++] = '/';
loopDir[loopDirLen] = '\0';
mntent* mentry;
while ((mentry = getmntent(fp)) != NULL) {
if (!strncmp(mentry->mnt_dir, loopDir, loopDirLen)) {
int fd = open(mentry->mnt_fsname, O_RDONLY | O_CLOEXEC);
if (fd >= 0) {
struct loop_info64 li;
if (ioctl(fd, LOOP_GET_STATUS64, &li) >= 0) {
cli->sendMsg(ResponseCode::AsecListResult,
(const char*) li.lo_file_name, false);
}
close(fd);
}
}
}
endmntent(fp);
return 0;
}
extern "C" int vold_unmountAll(void) {
VolumeManager *vm = VolumeManager::Instance();
return vm->unmountAll();
}
bool VolumeManager::isMountpointMounted(const char *mp)
{
FILE *fp = setmntent("/proc/mounts", "r");
if (fp == NULL) {
SLOGE("Error opening /proc/mounts (%s)", strerror(errno));
return false;
}
bool found_mp = false;
mntent* mentry;
while ((mentry = getmntent(fp)) != NULL) {
if (strcmp(mentry->mnt_dir, mp) == 0) {
found_mp = true;
break;
}
}
endmntent(fp);
return found_mp;
}
int VolumeManager::mkdirs(const char* path) {
// Only offer to create directories for paths managed by vold
if (strncmp(path, "/storage/", 9) == 0) {
// fs_mkdirs() does symlink checking and relative path enforcement
return fs_mkdirs(path, 0700);
} else {
SLOGE("Failed to find mounted volume for %s", path);
return -EINVAL;
}
}
static size_t kAppFuseMaxMountPointName = 32;
static android::status_t getMountPath(uid_t uid, const std::string& name, std::string* path) {
if (name.size() > kAppFuseMaxMountPointName) {
LOG(ERROR) << "AppFuse mount name is too long.";
return -EINVAL;
}
for (size_t i = 0; i < name.size(); i++) {
if (!isalnum(name[i])) {
LOG(ERROR) << "AppFuse mount name contains invalid character.";
return -EINVAL;
}
}
*path = android::base::StringPrintf("/mnt/appfuse/%d_%s", uid, name.c_str());
return android::OK;
}
static android::status_t mountInNamespace(uid_t uid, int device_fd, const std::string& path) {
// Remove existing mount.
android::vold::ForceUnmount(path);
const auto opts = android::base::StringPrintf(
"fd=%i,"
"rootmode=40000,"
"default_permissions,"
"allow_other,"
"user_id=%d,group_id=%d,"
"context=\"u:object_r:app_fuse_file:s0\","
"fscontext=u:object_r:app_fusefs:s0",
device_fd,
uid,
uid);
const int result = TEMP_FAILURE_RETRY(mount(
"/dev/fuse", path.c_str(), "fuse",
MS_NOSUID | MS_NODEV | MS_NOEXEC | MS_NOATIME, opts.c_str()));
if (result != 0) {
PLOG(ERROR) << "Failed to mount " << path;
return -errno;
}
return android::OK;
}
static android::status_t runCommandInNamespace(const std::string& command,
uid_t uid,
pid_t pid,
const std::string& path,
int device_fd) {
if (DEBUG_APPFUSE) {
LOG(DEBUG) << "Run app fuse command " << command << " for the path " << path
<< " in namespace " << uid;
}
unique_fd dir(open("/proc", O_RDONLY | O_DIRECTORY | O_CLOEXEC));
if (dir.get() == -1) {
PLOG(ERROR) << "Failed to open /proc";
return -errno;
}
// Obtains process file descriptor.
const std::string pid_str = android::base::StringPrintf("%d", pid);
const unique_fd pid_fd(
openat(dir.get(), pid_str.c_str(), O_RDONLY | O_DIRECTORY | O_CLOEXEC));
if (pid_fd.get() == -1) {
PLOG(ERROR) << "Failed to open /proc/" << pid;
return -errno;
}
// Check UID of process.
{
struct stat sb;
const int result = fstat(pid_fd.get(), &sb);
if (result == -1) {
PLOG(ERROR) << "Failed to stat /proc/" << pid;
return -errno;
}
if (sb.st_uid != AID_SYSTEM) {
LOG(ERROR) << "Only system can mount appfuse. UID expected=" << AID_SYSTEM
<< ", actual=" << sb.st_uid;
return -EPERM;
}
}
// Matches so far, but refuse to touch if in root namespace
{
char rootName[PATH_MAX];
char pidName[PATH_MAX];
const int root_result =
android::vold::SaneReadLinkAt(dir.get(), "1/ns/mnt", rootName, PATH_MAX);
const int pid_result =
android::vold::SaneReadLinkAt(pid_fd.get(), "ns/mnt", pidName, PATH_MAX);
if (root_result == -1) {
LOG(ERROR) << "Failed to readlink for /proc/1/ns/mnt";
return -EPERM;
}
if (pid_result == -1) {
LOG(ERROR) << "Failed to readlink for /proc/" << pid << "/ns/mnt";
return -EPERM;
}
if (!strcmp(rootName, pidName)) {
LOG(ERROR) << "Don't mount appfuse in root namespace";
return -EPERM;
}
}
// We purposefully leave the namespace open across the fork
unique_fd ns_fd(openat(pid_fd.get(), "ns/mnt", O_RDONLY)); // not O_CLOEXEC
if (ns_fd.get() < 0) {
PLOG(ERROR) << "Failed to open namespace for /proc/" << pid << "/ns/mnt";
return -errno;
}
int child = fork();
if (child == 0) {
if (setns(ns_fd.get(), CLONE_NEWNS) != 0) {
PLOG(ERROR) << "Failed to setns";
_exit(-errno);
}
if (command == "mount") {
_exit(mountInNamespace(uid, device_fd, path));
} else if (command == "unmount") {
// If it's just after all FD opened on mount point are closed, umount2 can fail with
// EBUSY. To avoid the case, specify MNT_DETACH.
if (umount2(path.c_str(), UMOUNT_NOFOLLOW | MNT_DETACH) != 0 &&
errno != EINVAL && errno != ENOENT) {
PLOG(ERROR) << "Failed to unmount directory.";
_exit(-errno);
}
if (rmdir(path.c_str()) != 0) {
PLOG(ERROR) << "Failed to remove the mount directory.";
_exit(-errno);
}
_exit(android::OK);
} else {
LOG(ERROR) << "Unknown appfuse command " << command;
_exit(-EPERM);
}
}
if (child == -1) {
PLOG(ERROR) << "Failed to folk child process";
return -errno;
}
android::status_t status;
TEMP_FAILURE_RETRY(waitpid(child, &status, 0));
return status;
}
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::mountAppFuse(uid_t uid, pid_t pid, int mountId,
android::base::unique_fd* device_fd) {
std::string name = std::to_string(mountId);
// Check mount point name.
std::string path;
if (getMountPath(uid, name, &path) != android::OK) {
LOG(ERROR) << "Invalid mount point name";
return -1;
}
// Create directories.
const android::status_t result = android::vold::PrepareDir(path, 0700, 0, 0);
if (result != android::OK) {
PLOG(ERROR) << "Failed to prepare directory " << path;
return -1;
}
// Open device FD.
device_fd->reset(open("/dev/fuse", O_RDWR)); // not O_CLOEXEC
if (device_fd->get() == -1) {
PLOG(ERROR) << "Failed to open /dev/fuse";
return -1;
}
// Mount.
return runCommandInNamespace("mount", uid, pid, path, device_fd->get());
}
int VolumeManager::unmountAppFuse(uid_t uid, pid_t pid, int mountId) {
std::string name = std::to_string(mountId);
// Check mount point name.
std::string path;
if (getMountPath(uid, name, &path) != android::OK) {
LOG(ERROR) << "Invalid mount point name";
return -1;
}
return runCommandInNamespace("unmount", uid, pid, path, -1 /* device_fd */);
}
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