platform_system_core/libcutils/multiuser.c
Jeff Sharkey bd2ecd8e6d Allocate a GID range for external cache files.
We can't reuse the GID range for internal cache files, otherwise
we don't have a way to tease apart the difference when deciding if
it's safe to move apps.

Test: builds, boots
Bug: 37193650
Change-Id: I22c4e575cd557636e74c5c73035adb1d4dcbb7f7
2017-04-17 14:59:51 -06:00

66 lines
2.1 KiB
C

/*
* Copyright (C) 2012 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 <cutils/multiuser.h>
#include <private/android_filesystem_config.h>
userid_t multiuser_get_user_id(uid_t uid) {
return uid / AID_USER_OFFSET;
}
appid_t multiuser_get_app_id(uid_t uid) {
return uid % AID_USER_OFFSET;
}
uid_t multiuser_get_uid(userid_t user_id, appid_t app_id) {
return (user_id * AID_USER_OFFSET) + (app_id % AID_USER_OFFSET);
}
gid_t multiuser_get_cache_gid(userid_t user_id, appid_t app_id) {
if (app_id >= AID_APP_START && app_id <= AID_APP_END) {
return multiuser_get_uid(user_id, (app_id - AID_APP_START) + AID_CACHE_GID_START);
} else {
return -1;
}
}
gid_t multiuser_get_ext_gid(userid_t user_id, appid_t app_id) {
if (app_id >= AID_APP_START && app_id <= AID_APP_END) {
return multiuser_get_uid(user_id, (app_id - AID_APP_START) + AID_EXT_GID_START);
} else {
return -1;
}
}
gid_t multiuser_get_ext_cache_gid(userid_t user_id, appid_t app_id) {
if (app_id >= AID_APP_START && app_id <= AID_APP_END) {
return multiuser_get_uid(user_id, (app_id - AID_APP_START) + AID_EXT_CACHE_GID_START);
} else {
return -1;
}
}
gid_t multiuser_get_shared_gid(userid_t user_id, appid_t app_id) {
if (app_id >= AID_APP_START && app_id <= AID_APP_END) {
return multiuser_get_uid(user_id, (app_id - AID_APP_START) + AID_SHARED_GID_START);
} else {
return -1;
}
}
gid_t multiuser_get_shared_app_gid(uid_t uid) {
return multiuser_get_shared_gid(multiuser_get_user_id(uid), multiuser_get_app_id(uid));
}