--[[
LuCI - Firewall model

Copyright 2009 Jo-Philipp Wich <xm@subsignal.org>

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

]]--

local type, pairs, ipairs, table, luci, math
	= type, pairs, ipairs, table, luci, math

local lmo = require "lmo"
local utl = require "luci.util"
local uci = require "luci.model.uci"

module "luci.model.firewall"


local uci_r, uci_s

function _valid_id(x)
	return (x and #x > 0 and x:match("^[a-zA-Z0-9_]+$"))
end

function _get(c, s, o)
	return uci_r:get(c, s, o)
end

function _set(c, s, o, v)
	if v ~= nil then
		if type(v) == "boolean" then v = v and "1" or "0" end
		return uci_r:set(c, s, o, v)
	else
		return uci_r:delete(c, s, o)
	end
end


function init(cursor)
	uci_r = cursor or uci_r or uci.cursor()
	uci_s = uci_r:substate()

	return _M
end

function save(self, ...)
	uci_r:save(...)
	uci_r:load(...)
end

function commit(self, ...)
	uci_r:commit(...)
	uci_r:load(...)
end

function get_defaults()
	return defaults()
end

function new_zone(self)
	local name = "newzone"
	local count = 1

	while self:get_zone(name) do
		count = count + 1
		name = "newzone%d" % count
	end

	return self:add_zone(name)
end

function add_zone(self, n)
	if _valid_id(n) and not self:get_zone(n) then
		local d = defaults()
		local z = uci_r:section("firewall", "zone", nil, {
			name    = n,
			network = " ",
			input   = d:input()   or "DROP",
			forward = d:forward() or "DROP",
			output  = d:output()  or "DROP"
		})

		return z and zone(z)
	end
end

function get_zone(self, n)
	if uci_r:get("firewall", n) == "zone" then
		return zone(n)
	else
		local z
		uci_r:foreach("firewall", "zone",
			function(s)
				if n and s.name == n then
					z = s['.name']
					return false
				end
			end)
		return z and zone(z)
	end
end

function get_zones(self)
	local zones = { }
	local znl = { }

	uci_r:foreach("firewall", "zone",
		function(s)
			if s.name then
				znl[s.name] = zone(s['.name'])
			end
		end)

	local z
	for z in utl.kspairs(znl) do
		zones[#zones+1] = znl[z]
	end

	return zones
end

function get_zone_by_network(self, net)
	local z

	uci_r:foreach("firewall", "zone",
		function(s)
			if s.name and net then
				local n
				for n in utl.imatch(s.network or s.name) do
					if n == net then
						z = s['.name']
						return false
					end
				end
			end
		end)

	return z and zone(z)
end

function del_zone(self, n)
	local r = false

	if uci_r:get("firewall", n) == "zone" then
		local z = uci_r:get("firewall", n, "name")
		r = uci_r:delete("firewall", n)
		n = z
	else
		uci_r:foreach("firewall", "zone",
			function(s)
				if n and s.name == n then
					r = uci_r:delete("firewall", s['.name'])
					return false
				end
			end)
	end

	if r then
		uci_r:foreach("firewall", "rule",
			function(s)
				if s.src == n or s.dest == n then
					uci_r:delete("firewall", s['.name'])
				end
			end)

		uci_r:foreach("firewall", "redirect",
			function(s)
				if s.src == n or s.dest == n then
					uci_r:delete("firewall", s['.name'])
				end
			end)

		uci_r:foreach("firewall", "forwarding",
			function(s)
				if s.src == n or s.dest == n then
					uci_r:delete("firewall", s['.name'])
				end
			end)
	end

	return r
end

function rename_zone(self, old, new)
	local r = false

	if _valid_id(new) and not self:get_zone(new) then
		uci_r:foreach("firewall", "zone",
			function(s)
				if old and s.name == old then
					if not s.network then
						uci_r:set("firewall", s['.name'], "network", old)
					end
					uci_r:set("firewall", s['.name'], "name", new)
					r = true
					return false
				end
			end)

		if r then
			uci_r:foreach("firewall", "rule",
				function(s)
					if s.src == old then
						uci_r:set("firewall", s['.name'], "src", new)
					end
					if s.dest == old then
						uci_r:set("firewall", s['.name'], "dest", new)
					end
				end)

			uci_r:foreach("firewall", "redirect",
				function(s)
					if s.src == old then
						uci_r:set("firewall", s['.name'], "src", new)
					end
					if s.dest == old then
						uci_r:set("firewall", s['.name'], "dest", new)
					end
				end)

			uci_r:foreach("firewall", "forwarding",
				function(s)
					if s.src == old then
						uci_r:set("firewall", s['.name'], "src", new)
					end
					if s.dest == old then
						uci_r:set("firewall", s['.name'], "dest", new)
					end
				end)
		end
	end

	return r
end

function del_network(self, net)
	local z
	if net then
		for _, z in ipairs(self:get_zones()) do
			z:del_network(net)
		end
	end
end


defaults = utl.class()
function defaults.__init__(self)
	uci_r:foreach("firewall", "defaults",
		function(s)
			self.sid  = s['.name']
			return false
		end)

	self.sid = self.sid or uci_r:section("firewall", "defaults", nil, { })
end

function defaults.get(self, opt)
	return _get("firewall", self.sid, opt)
end

function defaults.set(self, opt, val)
	return _set("firewall", self.sid, opt, val)
end

function defaults.syn_flood(self)
	return (self:get("syn_flood") == "1")
end

function defaults.drop_invalid(self)
	return (self:get("drop_invalid") == "1")
end

function defaults.input(self)
	return self:get("input") or "DROP"
end

function defaults.forward(self)
	return self:get("forward") or "DROP"
end

function defaults.output(self)
	return self:get("output") or "DROP"
end


zone = utl.class()
function zone.__init__(self, z)
	if uci_r:get("firewall", z) == "zone" then
		self.sid  = z
		self.data = uci_r:get_all("firewall", z)
	else
		uci_r:foreach("firewall", "zone",
			function(s)
				if s.name == z then
					self.sid  = s['.name']
					self.data = s
					return false
				end
			end)
	end
end

function zone.get(self, opt)
	return _get("firewall", self.sid, opt)
end

function zone.set(self, opt, val)
	return _set("firewall", self.sid, opt, val)
end

function zone.masq(self)
	return (self:get("masq") == "1")
end

function zone.name(self)
	return self:get("name")
end

function zone.network(self)
	return self:get("network")
end

function zone.input(self)
	return self:get("input") or defaults():input() or "DROP"
end

function zone.forward(self)
	return self:get("forward") or defaults():forward() or "DROP"
end

function zone.output(self)
	return self:get("output") or defaults():output() or "DROP"
end

function zone.add_network(self, net)
	if uci_r:get("network", net) == "interface" then
		local nets = { }

		local n
		for n in utl.imatch(self:get("network") or self:get("name")) do
			if n ~= net then
				nets[#nets+1] = n
			end
		end

		nets[#nets+1] = net

		_M:del_network(net)
		self:set("network", table.concat(nets, " "))
	end
end

function zone.del_network(self, net)
	local nets = { }

	local n
	for n in utl.imatch(self:get("network") or self:get("name")) do
		if n ~= net then
			nets[#nets+1] = n
		end
	end

	if #nets > 0 then
		self:set("network", table.concat(nets, " "))
	else
		self:set("network", " ")
	end
end

function zone.get_networks(self)
	local nets = { }

	local n
	for n in utl.imatch(self:get("network") or self:get("name")) do
		nets[#nets+1] = n
	end

	return nets
end

function zone.clear_networks(self)
	self:set("network", " ")
end

function zone.get_forwardings_by(self, what)
	local name = self:name()
	local forwards = { }

	uci_r:foreach("firewall", "forwarding",
		function(s)
			if s.src and s.dest and s[what] == name then
				forwards[#forwards+1] = forwarding(s['.name'])
			end
		end)

	return forwards
end

function zone.add_forwarding_to(self, dest)
	local exist, forward

	for _, forward in ipairs(self:get_forwardings_by('src')) do
		if forward:dest() == dest then
			exist = true
			break
		end
	end

	if not exist and dest ~= self:name() and _valid_id(dest) then
		local s = uci_r:section("firewall", "forwarding", nil, {
			src     = self:name(),
			dest    = dest
		})

		return s and forwarding(s)
	end
end

function zone.add_forwarding_from(self, src)
	local exist, forward

	for _, forward in ipairs(self:get_forwardings_by('dest')) do
		if forward:src() == src then
			exist = true
			break
		end
	end

	if not exist and src ~= self:name() and _valid_id(src) then
		local s = uci_r:section("firewall", "forwarding", nil, {
			src     = src,
			dest    = self:name()
		})

		return s and forwarding(s)
	end
end

function zone.del_forwardings_by(self, what)
	local name = self:name()

	uci_r:delete_all("firewall", "forwarding",
		function(s)
			return (s.src and s.dest and s[what] == name)
		end)
end

function zone.add_redirect(self, options)
	options = options or { }
	options.src = self:name()

	local s = uci_r:section("firewall", "redirect", nil, options)
	return s and redirect(s)
end

function zone.add_rule(self, options)
	options = options or { }
	options.src = self:name()

	local s = uci_r:section("firewall", "rule", nil, options)
	return s and rule(s)
end

function zone.get_color(self)
	if self and self:name() == "lan" then
		return "#90f090"
	elseif self and self:name() == "wan" then
		return "#f09090"
	elseif self then
		math.randomseed(lmo.hash(self:name()))

		local r   = math.random(128)
		local g   = math.random(128)
		local min = 0
		local max = 128

		if ( r + g ) < 128 then
			min = 128 - r - g
		else
			max = 255 - r - g
		end

		local b = min + math.floor( math.random() * ( max - min ) )

		return "#%02x%02x%02x" % { 0xFF - r, 0xFF - g, 0xFF - b }
	else
		return "#eeeeee"
	end
end


forwarding = utl.class()
function forwarding.__init__(self, f)
	self.sid = f
end

function forwarding.src(self)
	return uci_r:get("firewall", self.sid, "src")
end

function forwarding.dest(self)
	return uci_r:get("firewall", self.sid, "dest")
end

function forwarding.src_zone(self)
	return zone(self:src())
end

function forwarding.dest_zone(self)
	return zone(self:dest())
end


rule = utl.class()
function rule.__init__(self, f)
	self.sid = f
end

function rule.get(self, opt)
	return _get("firewall", self.sid, opt)
end

function rule.set(self, opt, val)
	return _set("firewall", self.sid, opt, val)
end

function rule.src(self)
	return uci_r:get("firewall", self.sid, "src")
end

function rule.dest(self)
	return uci_r:get("firewall", self.sid, "dest")
end

function rule.src_zone(self)
	return zone(self:src())
end

function rule.dest_zone(self)
	return zone(self:dest())
end


redirect = utl.class()
function redirect.__init__(self, f)
	self.sid = f
end

function redirect.get(self, opt)
	return _get("firewall", self.sid, opt)
end

function redirect.set(self, opt, val)
	return _set("firewall", self.sid, opt, val)
end

function redirect.src(self)
	return uci_r:get("firewall", self.sid, "src")
end

function redirect.dest(self)
	return uci_r:get("firewall", self.sid, "dest")
end

function redirect.src_zone(self)
	return zone(self:src())
end

function redirect.dest_zone(self)
	return zone(self:dest())
end