1 /*
2  * AppArmor security module
3  *
4  * This file contains AppArmor security identifier (sid) manipulation fns
5  *
6  * Copyright 2009-2010 Canonical Ltd.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation, version 2 of the
11  * License.
12  *
13  *
14  * AppArmor allocates a unique sid for every profile loaded.  If a profile
15  * is replaced it receives the sid of the profile it is replacing.
16  *
17  * The sid value of 0 is invalid.
18  */
19 
20 #include <linux/spinlock.h>
21 #include <linux/errno.h>
22 #include <linux/err.h>
23 
24 #include "include/sid.h"
25 
26 /* global counter from which sids are allocated */
27 static u32 global_sid;
28 static DEFINE_SPINLOCK(sid_lock);
29 
30 /* TODO FIXME: add sid to profile mapping, and sid recycling */
31 
32 /**
33  * aa_alloc_sid - allocate a new sid for a profile
34  */
aa_alloc_sid(void)35 u32 aa_alloc_sid(void)
36 {
37 	u32 sid;
38 
39 	/*
40 	 * TODO FIXME: sid recycling - part of profile mapping table
41 	 */
42 	spin_lock(&sid_lock);
43 	sid = (++global_sid);
44 	spin_unlock(&sid_lock);
45 	return sid;
46 }
47 
48 /**
49  * aa_free_sid - free a sid
50  * @sid: sid to free
51  */
aa_free_sid(u32 sid)52 void aa_free_sid(u32 sid)
53 {
54 	;			/* NOP ATM */
55 }
56