LXR linux/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 */
  27static u32 global_sid;
  28static 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 */
  35u32 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 */
  52void aa_free_sid(u32 sid)
  53{
  54        ;                       /* NOP ATM */
  55}
  56