461da83e67
This changes sdcardfs to modify the user and group in the underlying filesystem depending on its usage. Ownership is set by Android user, and package, as well as if the file is under obb or cache. Other files can be labeled by extension. Those values are set via the configfs interace. To add an entry, mkdir -p [configfs root]/sdcardfs/extensions/[gid]/[ext] Bug: 34262585 Change-Id: I4e030ce84f094a678376349b1a96923e5076a0f4 Signed-off-by: Daniel Rosenberg <drosen@google.com>
49 lines
1.8 KiB
C
49 lines
1.8 KiB
C
/*
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* fs/sdcardfs/multiuser.h
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*
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* Copyright (c) 2013 Samsung Electronics Co. Ltd
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* Authors: Daeho Jeong, Woojoong Lee, Seunghwan Hyun,
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* Sunghwan Yun, Sungjong Seo
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*
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* This program has been developed as a stackable file system based on
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* the WrapFS which written by
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*
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* Copyright (c) 1998-2011 Erez Zadok
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* Copyright (c) 2009 Shrikar Archak
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* Copyright (c) 2003-2011 Stony Brook University
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* Copyright (c) 2003-2011 The Research Foundation of SUNY
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*
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* This file is dual licensed. It may be redistributed and/or modified
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* under the terms of the Apache 2.0 License OR version 2 of the GNU
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* General Public License.
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*/
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#define AID_USER_OFFSET 100000 /* offset for uid ranges for each user */
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#define AID_APP_START 10000 /* first app user */
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#define AID_APP_END 19999 /* last app user */
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#define AID_CACHE_GID_START 20000 /* start of gids for apps to mark cached data */
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#define AID_EXT_GID_START 30000 /* start of gids for apps to mark external data */
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#define AID_SHARED_GID_START 50000 /* start of gids for apps in each user to share */
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typedef uid_t userid_t;
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typedef uid_t appid_t;
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static inline uid_t multiuser_get_uid(userid_t user_id, appid_t app_id) {
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return (user_id * AID_USER_OFFSET) + (app_id % AID_USER_OFFSET);
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}
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static inline gid_t multiuser_get_cache_gid(userid_t user_id, appid_t app_id) {
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if (app_id >= AID_APP_START && app_id <= AID_APP_END) {
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return multiuser_get_uid(user_id, (app_id - AID_APP_START) + AID_CACHE_GID_START);
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} else {
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return -1;
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}
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}
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static inline gid_t multiuser_get_ext_gid(userid_t user_id, appid_t app_id) {
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if (app_id >= AID_APP_START && app_id <= AID_APP_END) {
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return multiuser_get_uid(user_id, (app_id - AID_APP_START) + AID_EXT_GID_START);
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} else {
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return -1;
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}
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}
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