| /* |
| * 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(); |
| |
| const uid_t user_for_level = |
| (flags & android::os::IVold::STORAGE_FLAG_LEVEL_FROM_USER) ? user_id : -1; |
| |
| 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_for_level)) { |
| return false; |
| } |
| |
| if (volume_uuid.empty()) { |
| auto misc_de_path = android::vold::BuildDataMiscDePath(user_id); |
| 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_for_level)) { |
| 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_for_level)) { |
| return false; |
| } |
| |
| if (volume_uuid.empty()) { |
| auto misc_ce_path = android::vold::BuildDataMiscCePath(user_id); |
| 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); |
| |
| 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 (volume_uuid.empty()) { |
| if (flags & android::os::IVold::STORAGE_FLAG_CE) { |
| auto misc_ce_path = android::vold::BuildDataMiscCePath(user_id); |
| res &= rmrf_contents(misc_ce_path); |
| |
| 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(user_id); |
| res &= rmrf_contents(misc_de_path); |
| |
| 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; |
| } |
