(***************************************************************************** * Copyright (c) 2005-2010 ETH Zurich, Switzerland * 2008-2015 Achim D. Brucker, Germany * 2009-2017 Université Paris-Sud, France * 2015-2017 The University of Sheffield, UK * * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * * Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials provided * with the distribution. * * * Neither the name of the copyright holders nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. *****************************************************************************) subsection ‹Policy Combinators› theory PolicyCombinators imports PolicyCore begin text‹In order to ease the specification of a concrete policy, we define some combinators. Using these combinators, the specification of a policy gets very easy, and can be done similarly as in tools like IPTables.› definition allow_all_from :: "'α::adr net ⇒ (('α,'β) packet ↦ unit)" where "allow_all_from src_net = {pa. src pa ⊏ src_net} ◃ A⇩U " definition deny_all_from :: "'α::adr net ⇒ (('α,'β) packet ↦ unit)" where "deny_all_from src_net = {pa. src pa ⊏ src_net} ◃D⇩U " definition allow_all_to :: "'α::adr net ⇒ (('α,'β) packet ↦ unit)" where "allow_all_to dest_net = {pa. dest pa ⊏ dest_net} ◃ A⇩U" definition deny_all_to :: "'α::adr net ⇒ (('α,'β) packet ↦ unit)" where "deny_all_to dest_net = {pa. dest pa ⊏ dest_net} ◃D⇩U " definition allow_all_from_to :: "'α::adr net ⇒ 'α::adr net ⇒ (('α,'β) packet ↦ unit)" where "allow_all_from_to src_net dest_net = {pa. src pa ⊏ src_net ∧ dest pa ⊏ dest_net} ◃ A⇩U " definition deny_all_from_to :: "'α::adr net ⇒ 'α::adr net ⇒ (('α,'β) packet ↦ unit)" where "deny_all_from_to src_net dest_net = {pa. src pa ⊏ src_net ∧ dest pa ⊏ dest_net} ◃ D⇩U" text‹All these combinators and the default rules are put into one single lemma called ‹PolicyCombinators› to facilitate proving over policies.› lemmas PolicyCombinators = allow_all_from_def deny_all_from_def allow_all_to_def deny_all_to_def allow_all_from_to_def deny_all_from_to_def UPFDefs end