Restrict the SELinux user map user MLS value to 0-1023

https://fedorahosted.org/freeipa/ticket/3001

tests/test_xmlrpc/test_selinuxusermap_plugin.py

@@ -643,6 +643,17 @@ class test_selinuxusermap(Declarative):
         ),
 
 
+        dict(
+            desc='Create rule with invalid MLS xguest_u:s0:c0.c1028',
+            command=(
+                'selinuxusermap_add', [rule1], dict(ipaselinuxuser=u'xguest_u:s0-s0:c0.c1028')
+            ),
+            expected=errors.ValidationError(name='selinuxuser',
+                error=u'Invalid MCS value, must match c[0-1023].c[0-1023] ' +
+                    u'and/or c[0-1023]-c[0-c0123]'),
+        ),
+
+
         dict(
             desc='Create rule with invalid user via setattr',
             command=(