platform_system_vold/vold_prepare_subdirs.cpp
Mohammad Samiul Islam b459591fd1 Create misc_ce and misc_de directories on /mnt/expand
We want to store sdk data on the same volume as app data. Since sdk data
is stored in misc_ce and misc_de directory, we need to ensure they exist
on adopted storage mounted at /mnt/expand/<volume-uuid>.

This CL creates `/mnt/expand/<volume-uuid>/misc_{ce,de}` directories
when disk is mouted and then when user storage is prepared, the sdk root
directory is created.

By having these directories, we can now move the sdk data to other
volume when app data is moved.

Bug: b/222034645
Test: atest SdkSandboxStorageHostTest (see ag/17120883)
Ignore-AOSP-First: End to end test added which exists in internal branch
    only. Will cherry-pick this CL to aosp standalone once it is safely
    merged to internal branch.
Change-Id: I0e73d9ce105abec4b77c378cde58aa7365258f01
2022-03-08 10:37:31 +00:00

301 lines
12 KiB
C++

/*
* Copyright (C) 2017 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.
*/
/*
* Tool to create a directory with the right SELinux context applied, or
* apply the context if it's absent. Also fixes mode, uid, gid.
*/
#include <iostream>
#include <string>
#include <vector>
#include <dirent.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <android-base/logging.h>
#include <android-base/scopeguard.h>
#include <cutils/fs.h>
#include <selinux/android.h>
#include "Utils.h"
#include "android/os/IVold.h"
#include <private/android_filesystem_config.h>
static void usage(const char* progname) {
std::cerr << "Usage: " << progname << " [ prepare | destroy ] <volume_uuid> <user_id> <flags>"
<< std::endl;
exit(-1);
}
static bool small_int(const std::string& s) {
return !s.empty() && s.size() < 7 && s.find_first_not_of("0123456789") == std::string::npos;
}
static bool valid_uuid(const std::string& s) {
return s.size() < 40 && s.find_first_not_of("0123456789abcdefABCDEF-_") == std::string::npos;
}
static bool prepare_dir_for_user(struct selabel_handle* sehandle, mode_t mode, uid_t uid, gid_t gid,
const std::string& path, uid_t user_id) {
auto clearfscreatecon = android::base::make_scope_guard([] { setfscreatecon(nullptr); });
auto secontext = std::unique_ptr<char, void (*)(char*)>(nullptr, freecon);
if (sehandle) {
char* tmp_secontext;
if (selabel_lookup(sehandle, &tmp_secontext, path.c_str(), S_IFDIR) == 0) {
secontext.reset(tmp_secontext);
if (user_id != (uid_t)-1) {
if (selinux_android_context_with_level(secontext.get(), &tmp_secontext, user_id,
(uid_t)-1) != 0) {
PLOG(ERROR) << "Unable to create context with level for: " << path;
return false;
}
secontext.reset(tmp_secontext); // Free the context
}
}
}
LOG(DEBUG) << "Setting up mode " << std::oct << mode << std::dec << " uid " << uid << " gid "
<< gid << " context " << (secontext ? secontext.get() : "null")
<< " on path: " << path;
if (secontext) {
if (setfscreatecon(secontext.get()) != 0) {
PLOG(ERROR) << "Unable to setfscreatecon for: " << path;
return false;
}
}
if (fs_prepare_dir(path.c_str(), mode, uid, gid) != 0) {
return false;
}
if (secontext) {
char* tmp_oldsecontext = nullptr;
if (lgetfilecon(path.c_str(), &tmp_oldsecontext) < 0) {
PLOG(ERROR) << "Unable to read secontext for: " << path;
return false;
}
auto oldsecontext = std::unique_ptr<char, void (*)(char*)>(tmp_oldsecontext, freecon);
if (strcmp(secontext.get(), oldsecontext.get()) != 0) {
LOG(INFO) << "Relabelling from " << ((char*)oldsecontext.get()) << " to "
<< ((char*)secontext.get()) << ": " << path;
if (lsetfilecon(path.c_str(), secontext.get()) != 0) {
PLOG(ERROR) << "Relabelling failed for: " << path;
return false;
}
}
}
return true;
}
static bool prepare_dir(struct selabel_handle* sehandle, mode_t mode, uid_t uid, gid_t gid,
const std::string& path) {
return prepare_dir_for_user(sehandle, mode, uid, gid, path, (uid_t)-1);
}
static bool rmrf_contents(const std::string& path) {
auto dirp = std::unique_ptr<DIR, int (*)(DIR*)>(opendir(path.c_str()), closedir);
if (!dirp) {
PLOG(ERROR) << "Unable to open directory: " << path;
return false;
}
bool res = true;
for (;;) {
errno = 0;
auto const entry = readdir(dirp.get());
if (!entry) {
if (errno) {
PLOG(ERROR) << "readdir failed on: " << path;
return false;
}
return res;
}
if (entry->d_name[0] == '.') continue;
auto subdir = path + "/" + entry->d_name;
if (0 !=
android::vold::ForkExecvp(std::vector<std::string>{"/system/bin/rm", "-rf", subdir})) {
LOG(ERROR) << "rm -rf failed on " << subdir;
res = false;
}
}
}
static bool prepare_apex_subdirs(struct selabel_handle* sehandle, const std::string& path) {
if (!prepare_dir(sehandle, 0711, 0, 0, path + "/apexdata")) return false;
auto dirp = std::unique_ptr<DIR, int (*)(DIR*)>(opendir("/apex"), closedir);
if (!dirp) {
PLOG(ERROR) << "Unable to open apex directory";
return false;
}
struct dirent* entry;
while ((entry = readdir(dirp.get())) != nullptr) {
if (entry->d_type != DT_DIR) continue;
const char* name = entry->d_name;
// skip any starting with "."
if (name[0] == '.') continue;
if (strchr(name, '@') != NULL) continue;
if (!prepare_dir(sehandle, 0771, AID_ROOT, AID_SYSTEM, path + "/apexdata/" + name)) {
return false;
}
}
return true;
}
static bool prepare_subdirs(const std::string& volume_uuid, int user_id, int flags) {
struct selabel_handle* sehandle = selinux_android_file_context_handle();
if (flags & android::os::IVold::STORAGE_FLAG_DE) {
auto user_de_path = android::vold::BuildDataUserDePath(volume_uuid, user_id);
if (!prepare_dir_for_user(sehandle, 0771, AID_SYSTEM, AID_SYSTEM, user_de_path, user_id)) {
return false;
}
auto misc_de_path = android::vold::BuildDataMiscDePath(volume_uuid, user_id);
if (!prepare_dir_for_user(sehandle, 0771, AID_SYSTEM, AID_SYSTEM,
misc_de_path + "/sdksandbox", user_id)) {
return false;
}
if (volume_uuid.empty()) {
if (!prepare_dir(sehandle, 0700, 0, 0, misc_de_path + "/vold")) return false;
if (!prepare_dir(sehandle, 0700, 0, 0, misc_de_path + "/storaged")) return false;
if (!prepare_dir(sehandle, 0700, 0, 0, misc_de_path + "/rollback")) return false;
// TODO: Return false if this returns false once sure this should succeed.
prepare_dir(sehandle, 0700, 0, 0, misc_de_path + "/apexrollback");
prepare_apex_subdirs(sehandle, misc_de_path);
auto profiles_de_path = android::vold::BuildDataProfilesDePath(user_id);
if (!prepare_dir_for_user(sehandle, 0771, AID_SYSTEM, AID_SYSTEM, profiles_de_path,
user_id)) {
return false;
}
auto vendor_de_path = android::vold::BuildDataVendorDePath(user_id);
if (!prepare_dir(sehandle, 0700, AID_SYSTEM, AID_SYSTEM, vendor_de_path + "/fpdata")) {
return false;
}
auto facedata_path = vendor_de_path + "/facedata";
if (!prepare_dir(sehandle, 0700, AID_SYSTEM, AID_SYSTEM, facedata_path)) {
return false;
}
}
}
if (flags & android::os::IVold::STORAGE_FLAG_CE) {
auto user_ce_path = android::vold::BuildDataUserCePath(volume_uuid, user_id);
if (!prepare_dir_for_user(sehandle, 0771, AID_SYSTEM, AID_SYSTEM, user_ce_path, user_id)) {
return false;
}
auto misc_ce_path = android::vold::BuildDataMiscCePath(volume_uuid, user_id);
if (!prepare_dir_for_user(sehandle, 0771, AID_SYSTEM, AID_SYSTEM,
misc_ce_path + "/sdksandbox", user_id)) {
return false;
}
if (volume_uuid.empty()) {
if (!prepare_dir(sehandle, 0700, 0, 0, misc_ce_path + "/vold")) return false;
if (!prepare_dir(sehandle, 0700, 0, 0, misc_ce_path + "/storaged")) return false;
if (!prepare_dir(sehandle, 0700, 0, 0, misc_ce_path + "/rollback")) return false;
// TODO: Return false if this returns false once sure this should succeed.
prepare_dir(sehandle, 0700, 0, 0, misc_ce_path + "/apexrollback");
prepare_apex_subdirs(sehandle, misc_ce_path);
// Give gmscore (who runs in cache group) access to the checkin directory. Also provide
// the user id to set the correct selinux mls_level.
if (!prepare_dir_for_user(sehandle, 0770, AID_SYSTEM, AID_CACHE,
misc_ce_path + "/checkin", user_id)) {
// TODO(b/203742483) the checkin directory was created with the wrong permission &
// context. Delete the directory to get these devices out of the bad state. Revert
// the change once the droidfood population is on newer build.
LOG(INFO) << "Failed to prepare the checkin directory, deleting for recreation";
android::vold::DeleteDirContentsAndDir(misc_ce_path + "/checkin");
if (!prepare_dir_for_user(sehandle, 0770, AID_SYSTEM, AID_CACHE,
misc_ce_path + "/checkin", user_id)) {
return false;
}
}
auto system_ce_path = android::vold::BuildDataSystemCePath(user_id);
if (!prepare_dir(sehandle, 0700, AID_SYSTEM, AID_SYSTEM, system_ce_path + "/backup")) {
return false;
}
if (!prepare_dir(sehandle, 0700, AID_SYSTEM, AID_SYSTEM,
system_ce_path + "/backup_stage")) {
return false;
}
auto vendor_ce_path = android::vold::BuildDataVendorCePath(user_id);
auto facedata_path = vendor_ce_path + "/facedata";
if (!prepare_dir(sehandle, 0700, AID_SYSTEM, AID_SYSTEM, facedata_path)) {
return false;
}
}
}
return true;
}
static bool destroy_subdirs(const std::string& volume_uuid, int user_id, int flags) {
bool res = true;
if (flags & android::os::IVold::STORAGE_FLAG_CE) {
auto misc_ce_path = android::vold::BuildDataMiscCePath(volume_uuid, user_id);
res &= rmrf_contents(misc_ce_path);
if (volume_uuid.empty()) {
auto vendor_ce_path = android::vold::BuildDataVendorCePath(user_id);
res &= rmrf_contents(vendor_ce_path);
}
}
if (flags & android::os::IVold::STORAGE_FLAG_DE) {
auto misc_de_path = android::vold::BuildDataMiscDePath(volume_uuid, user_id);
res &= rmrf_contents(misc_de_path);
if (volume_uuid.empty()) {
auto vendor_de_path = android::vold::BuildDataVendorDePath(user_id);
res &= rmrf_contents(vendor_de_path);
}
}
return res;
}
int main(int argc, const char* const argv[]) {
android::base::InitLogging(const_cast<char**>(argv));
std::vector<std::string> args(argv + 1, argv + argc);
if (args.size() != 4 || !valid_uuid(args[1]) || !small_int(args[2]) || !small_int(args[3])) {
usage(argv[0]);
return -1;
}
auto volume_uuid = args[1];
int user_id = stoi(args[2]);
int flags = stoi(args[3]);
if (args[0] == "prepare") {
if (!prepare_subdirs(volume_uuid, user_id, flags)) return -1;
} else if (args[0] == "destroy") {
if (!destroy_subdirs(volume_uuid, user_id, flags)) return -1;
} else {
usage(argv[0]);
return -1;
}
return 0;
}