AppArmor: core policy routines
The basic routines and defines for AppArmor policy. AppArmor policy
is defined by a few basic components.
profiles - the basic unit of confinement contain all the information
to enforce policy on a task
Profiles tend to be named after an executable that they
will attach to but this is not required.
namespaces - a container for a set of profiles that will be used
during attachment and transitions between profiles.
sids - which provide a unique id for each profile
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/apparmor/sid.c b/security/apparmor/sid.c
new file mode 100644
index 0000000..f0b34f7
--- /dev/null
+++ b/security/apparmor/sid.c
@@ -0,0 +1,55 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor security identifier (sid) manipulation fns
+ *
+ * Copyright 2009-2010 Canonical Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ *
+ *
+ * AppArmor allocates a unique sid for every profile loaded. If a profile
+ * is replaced it receives the sid of the profile it is replacing.
+ *
+ * The sid value of 0 is invalid.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+
+#include "include/sid.h"
+
+/* global counter from which sids are allocated */
+static u32 global_sid;
+static DEFINE_SPINLOCK(sid_lock);
+
+/* TODO FIXME: add sid to profile mapping, and sid recycling */
+
+/**
+ * aa_alloc_sid - allocate a new sid for a profile
+ */
+u32 aa_alloc_sid(void)
+{
+ u32 sid;
+
+ /*
+ * TODO FIXME: sid recycling - part of profile mapping table
+ */
+ spin_lock(&sid_lock);
+ sid = (++global_sid);
+ spin_unlock(&sid_lock);
+ return sid;
+}
+
+/**
+ * aa_free_sid - free a sid
+ * @sid: sid to free
+ */
+void aa_free_sid(u32 sid)
+{
+ ; /* NOP ATM */
+}