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VolumeManager.cpp
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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.
*/
#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/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 "Benchmark.h"
#include "EmulatedVolume.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;
/*
* 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";
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 {
strcpy(buffer, loopDevice);
*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;
}
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();
// 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, virtio-blk (the latter is
// emulator-specific; see Disk.cpp for details) and UFS card
// devices are SD, and that everything else is USB
int flags = source->getFlags();
if (major == kMajorBlockMmc
|| (eventPath.find("ufs") != std::string::npos)
|| (android::vold::IsRunningInEmulator()
&& major >= (int) kMajorBlockExperimentalMin
&& major <= (int) kMajorBlockExperimentalMax)) {
flags |= android::vold::Disk::Flags::kSd;
} else {
flags |= android::vold::Disk::Flags::kUsb;
}
android::vold::Disk* disk = (source->getPartNum() == -1) ?
new android::vold::Disk(eventPath, device,
source->getNickname(), flags) :
new android::vold::DiskPartition(eventPath, device,
source->getNickname(), flags,
source->getPartNum(),
source->getFsType(), source->getMntOpts());
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) {
if (mInternalEmulated->getId() == id) {
return mInternalEmulated;
}
for (const auto& disk : mDisks) {
auto vol = disk->findVolume(id);
if (vol != nullptr) {
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);
}
}
nsecs_t VolumeManager::benchmarkPrivate(const std::string& id) {
std::string path;
if (id == "private" || id == "null") {
path = "/data";
} else {
auto vol = findVolume(id);
if (vol != nullptr && vol->getState() == android::vold::VolumeBase::State::kMounted) {
path = vol->getPath();
}
}
if (path.empty()) {
LOG(WARNING) << "Failed to find volume for " << id;
return -1;
}
return android::vold::BenchmarkPrivate(path);
}
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.
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
}
mInternalEmulated->destroy();
mInternalEmulated = nullptr;
for (const auto& disk : mDisks) {
disk->destroy();
}
mDisks.clear();
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) {
SLOGW("Tearing down stale mount %s", path.c_str());
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;
strcpy(dmDevice, loopDevice);
}
/*
* 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,