1 /*
2  * Copyright (C) 2012 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <cutils/multiuser.h>
18 #include <private/android_filesystem_config.h>
19 
multiuser_get_user_id(uid_t uid)20 userid_t multiuser_get_user_id(uid_t uid) {
21     return uid / AID_USER_OFFSET;
22 }
23 
multiuser_get_app_id(uid_t uid)24 appid_t multiuser_get_app_id(uid_t uid) {
25     return uid % AID_USER_OFFSET;
26 }
27 
multiuser_get_uid(userid_t user_id,appid_t app_id)28 uid_t multiuser_get_uid(userid_t user_id, appid_t app_id) {
29     return (user_id * AID_USER_OFFSET) + (app_id % AID_USER_OFFSET);
30 }
31 
multiuser_get_sdk_sandbox_uid(userid_t user_id,appid_t app_id)32 uid_t multiuser_get_sdk_sandbox_uid(userid_t user_id, appid_t app_id) {
33     int sdk_sandbox_offset = AID_SDK_SANDBOX_PROCESS_START - AID_APP_START;
34     if (app_id >= AID_APP_START && app_id <= AID_APP_END) {
35         return (user_id * AID_USER_OFFSET) + (app_id % AID_USER_OFFSET) + sdk_sandbox_offset;
36     } else {
37         return -1;
38     }
39 }
40 
multiuser_convert_sdk_sandbox_to_app_uid(uid_t uid)41 uid_t multiuser_convert_sdk_sandbox_to_app_uid(uid_t uid) {
42     appid_t app_id = multiuser_get_app_id(uid);
43     int sdk_sandbox_offset = AID_SDK_SANDBOX_PROCESS_START - AID_APP_START;
44     if (app_id >= AID_SDK_SANDBOX_PROCESS_START && app_id <= AID_SDK_SANDBOX_PROCESS_END) {
45         return uid - sdk_sandbox_offset;
46     } else {
47         return -1;
48     }
49 }
50 
multiuser_get_cache_gid(userid_t user_id,appid_t app_id)51 gid_t multiuser_get_cache_gid(userid_t user_id, appid_t app_id) {
52     if (app_id >= AID_APP_START && app_id <= AID_APP_END) {
53         return multiuser_get_uid(user_id, (app_id - AID_APP_START) + AID_CACHE_GID_START);
54     } else {
55         return -1;
56     }
57 }
58 
multiuser_get_ext_gid(userid_t user_id,appid_t app_id)59 gid_t multiuser_get_ext_gid(userid_t user_id, appid_t app_id) {
60     if (app_id >= AID_APP_START && app_id <= AID_APP_END) {
61         return multiuser_get_uid(user_id, (app_id - AID_APP_START) + AID_EXT_GID_START);
62     } else {
63         return -1;
64     }
65 }
66 
multiuser_get_ext_cache_gid(userid_t user_id,appid_t app_id)67 gid_t multiuser_get_ext_cache_gid(userid_t user_id, appid_t app_id) {
68     if (app_id >= AID_APP_START && app_id <= AID_APP_END) {
69         return multiuser_get_uid(user_id, (app_id - AID_APP_START) + AID_EXT_CACHE_GID_START);
70     } else {
71         return -1;
72     }
73 }
74 
multiuser_get_shared_gid(userid_t,appid_t app_id)75 gid_t multiuser_get_shared_gid(userid_t, appid_t app_id) {
76     if (app_id >= AID_APP_START && app_id <= AID_APP_END) {
77         return (app_id - AID_APP_START) + AID_SHARED_GID_START;
78     } else if (app_id >= AID_ROOT && app_id <= AID_APP_START) {
79         return app_id;
80     } else {
81         return -1;
82     }
83 }
84 
multiuser_get_shared_app_gid(uid_t uid)85 gid_t multiuser_get_shared_app_gid(uid_t uid) {
86     return multiuser_get_shared_gid(multiuser_get_user_id(uid), multiuser_get_app_id(uid));
87 }
88