UPF_Firewall/UPF_Firewall/Examples/PersonalFirewall/PersonalFirewallIpv4.thy

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* Copyright (c) 2005-2010 ETH Zurich, Switzerland
* 2008-2015 Achim D. Brucker, Germany
* 2009-2016 Université Paris-Sud, France
* 2015-2016 The University of Sheffield, UK
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subsection \<open>Personal Firewall IPv4\<close>
theory
PersonalFirewallIpv4
imports
"../../UPF-Firewall"
begin
text\<open>
The most basic firewall scenario; there is a personal PC on one side and the Internet on the
other. There are two policies: the first one allows all traffic from the PC to the Internet and
denies all coming into the PC. The second policy only allows specific ports from the PC. This
scenario comes in three variants: the first one specifies the allowed protocols directly, the
second together with their respective port numbers, the third one only with the port numbers.
\<close>
text\<open>
Definitions of the subnets
\<close>
definition
PC :: "(ipv4 net)" where
"PC = {{((a,b,c,d),e). a = 1 \<and> b = 3 \<and> c = 5 \<and> d = 2}}"
definition
Internet :: "ipv4 net" where
"Internet = {{((a,b,c,d),e). \<not> (a = 1 \<and> b = 3 \<and> c = 5 \<and> d = 2)}}"
definition
not_in_same_net :: "(ipv4,DummyContent) packet \<Rightarrow> bool" where
"not_in_same_net x = ((src x \<sqsubset> PC \<longrightarrow> dest x \<sqsubset> Internet) \<and> (src x \<sqsubset> Internet \<longrightarrow> dest x \<sqsubset> PC))"
text \<open>
Definitions of the policies
\<close>
definition
strictPolicy :: "(ipv4,DummyContent) FWPolicy" where
"strictPolicy = deny_all ++ allow_all_from_to PC Internet"
definition
PortPolicy :: "(ipv4,DummyContent) FWPolicy" where
"PortPolicy = deny_all ++ allow_from_ports_to {80::port,24,21} PC Internet"
definition
PortPolicyBig :: "(ipv4,DummyContent) FWPolicy" where
"PortPolicyBig = deny_all ++ allow_from_port_to (80::port) PC Internet++ allow_from_port_to (24::port) PC Internet++ allow_from_port_to (21::port) PC Internet"
lemmas policyLemmas = strictPolicy_def PortPolicy_def PC_def
Internet_def PortPolicyBig_def src_def dest_def
IPv4.src_port
IPv4.dest_port PolicyCombinators
PortCombinators in_subnet_def PortPolicyBig_def
end