security/apparmor/sid.c

   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  */
  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  */
  52 void aa_free_sid(u32 sid)
  53 {
  54         ;                       /* NOP ATM */
  55 }