dff44709cf
To support upcoming disk usage calculation optimizations, this change creates a new GID for each app that will be used to mark its cached data. We're allocating these unique GIDs so that we can use quotactl() to track cached data on a per-app basis. This change also tightens up the implementation of both the cache and shared GID calculation to ensure that they stay inside the valid ranges, and includes tests to verify. Test: builds, boots, tests pass Bug: 27948817 Change-Id: Ie4377e5aae267f2da39a165888139228995987cb
50 lines
1.6 KiB
C
50 lines
1.6 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_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));
|
|
}
|