LSM/Audit: Introduce generic Audit LSM hooks

Introduce a generic Audit interface for security modules
by adding the following new LSM hooks:

audit_rule_init(field, op, rulestr, lsmrule)
audit_rule_known(krule)
audit_rule_match(secid, field, op, rule, actx)
audit_rule_free(rule)

Those hooks are only available if CONFIG_AUDIT is enabled.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Acked-by: James Morris <jmorris@namei.org>
Reviewed-by: Paul Moore <paul.moore@hp.com>
diff --git a/security/security.c b/security/security.c
index 290482b..2ef593e 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1120,3 +1120,28 @@
 }
 
 #endif	/* CONFIG_KEYS */
+
+#ifdef CONFIG_AUDIT
+
+int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule)
+{
+	return security_ops->audit_rule_init(field, op, rulestr, lsmrule);
+}
+
+int security_audit_rule_known(struct audit_krule *krule)
+{
+	return security_ops->audit_rule_known(krule);
+}
+
+void security_audit_rule_free(void *lsmrule)
+{
+	security_ops->audit_rule_free(lsmrule);
+}
+
+int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule,
+			      struct audit_context *actx)
+{
+	return security_ops->audit_rule_match(secid, field, op, lsmrule, actx);
+}
+
+#endif /* CONFIG_AUDIT */