New controller based on SaferLUA

safer_lua/description.txt

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+SaferLUA [safer_lua], a subset of the language LUA for safe and secure LUA sandboxes
+
+
+

safer_lua/environ.lua

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+safer_lua.MaxCodeSize = 1000    -- size in length of byte code
+safer_lua.MaxTableSize = 1000   -- number of table entries considering string lenghts
+
+
+local BASE_ENV = {
+	Store = safer_lua.Store,
+	math = {
+		floor = math.floor
+	},
+	ticks = 0,
+}
+
+local function map(dest, source)
+  for k,v in pairs(source) do
+    dest[k] = v
+  end
+  return dest
+end
+
+function safer_lua.config(max_code_size, max_table_size)
+	safer_lua.MaxCodeSize = max_code_size
+	safer_lua.MaxTableSize = max_table_size
+end	
+
+local function compile(pos, text, label, err_clbk)
+	if safer_lua:check(text, label, err_clbk) == 0 then
+		text = text:gsub("%$", "S:")
+		local code, err = loadstring(text)
+		if not code then
+			err = err:gsub("%[string .+%]:", label)
+			err_clbk(pos, err) 
+		else
+			return code
+		end
+	end
+end
+
+function safer_lua.init(pos, init, loop, environ, err_clbk)
+	if #init > safer_lua.MaxCodeSize then
+		err_clbk(pos, "init() Code size limit exceeded")
+		return
+	end
+	if #loop > safer_lua.MaxCodeSize then
+		err_clbk(pos, "loop() Code size limit exceeded")
+		return
+	end
+	local code = compile(pos, init, "init() ", err_clbk)
+	if code then
+		local env = BASE_ENV
+		env.S = {}
+		env.S._G = _G
+		env.S = map(env.S, environ)
+		setfenv(code, env)
+		local res, err = pcall(code)
+		if not res then
+			err = err:gsub("%[string .+%]:", "init() ")
+			err_clbk(pos, err)
+		else
+			env = getfenv(code)
+			code = compile(pos, loop, "loop() ", err_clbk)
+			if code then
+				setfenv(code, env)
+				return code
+			end
+		end
+	end
+end
+
+function safer_lua.run_loop(pos, elapsed, code, err_clbk)
+	local env = getfenv(code)
+	env.event = false
+	env.ticks = env.ticks + 1
+	env.elapsed = elapsed
+	setfenv(code, env)
+	local res, err = pcall(code)
+	if not res then
+		err = err:gsub("%[string .+%]:", "loop() ")
+		err_clbk(pos, err)
+		return false
+	end
+	return true
+end
+
+function safer_lua.run_event(pos, code, err_clbk)
+	local env = getfenv(code)
+	env.event = true
+	setfenv(code, env)
+	local res, err = pcall(code)
+	if not res then
+		err = err:gsub("%[string .+%]:", "loop() ")
+		err_clbk(pos, err)
+		return false
+	end
+	return true
+end
+
+

safer_lua/init.lua

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+--[[
+
+	SaferLUA
+	========
+	
+	Copyright (C) 2018 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+]]--
+
+safer_lua = {}
+
+dofile(minetest.get_modpath("safer_lua") .. "/store.lua")
+dofile(minetest.get_modpath("safer_lua") .. "/scanner.lua")
+dofile(minetest.get_modpath("safer_lua") .. "/environ.lua")

safer_lua/mod.conf

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+name=safer_lua

safer_lua/readme.md

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+SaferLUA [safer_lua]
+====================
+
+A subset of the language LUA for safe and secure LUA sandboxes with:
+ - limited code length
+ - limited execution time
+ - limited memory use
+ - limited posibilities to call functions
+
+
+

safer_lua/scanner.lua

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+local function trim(s)
+  return (s:gsub("^%s*(.-)%s*$", "%1"))
+end
+
+function safer_lua:word(ch, pttrn)
+	local word = ""
+	while ch:match(pttrn) do
+		word = word .. ch
+		self.pos = self.pos + 1
+		ch = self.line:sub(self.pos, self.pos)
+	end
+	return word
+end
+
+function safer_lua:string(pttrn)
+	self.pos = self.pos + 1
+	local ch = self.line:sub(self.pos, self.pos)
+	while not ch:match(pttrn) and self.pos < #self.line do
+		self.pos = self.pos + 1
+		ch = self.line:sub(self.pos, self.pos)
+	end
+	self.pos = self.pos + 1
+	-- result is not needed
+end
+
+function safer_lua:scanner(text)
+	local lToken = {}
+	for idx, line in ipairs(text:split("\n")) do
+		self.line = line
+		self.pos = 1
+		self.line = trim(self.line)
+		self.line = self.line:split("--")[1]
+		if self.line then
+			-- devide line in tokens
+			table.insert(lToken, idx)  -- line number
+			while true do
+				if self.pos > #self.line then break end
+				local ch = self.line:sub(self.pos, self.pos)
+				if ch:match("[%u%l_]") then                       -- identifier?
+					table.insert(lToken, self:word(ch, "[%w_]"))
+				elseif ch:match("[%d]") then  -- number?
+					table.insert(lToken, self:word(ch, "[%d%xx]"))
+				elseif ch:match("'") then                         -- string?
+					self:string("'")
+				elseif ch:match('"') then                         -- string?
+					self:string('"')
+				elseif ch:match("[%s]") then                      -- Space?
+					self.pos = self.pos + 1
+				elseif ch:match("[:{}]") then                     -- critical tokens?
+					table.insert(lToken,ch)
+					self.pos = self.pos + 1
+				else
+					self.pos = self.pos + 1
+				end
+			end
+		end
+	end
+	return lToken
+end
+
+local InvalidKeywords = {
+	["while"] = true, 
+	["repeat"] = true, 
+	["break"] = true, 
+	["until"] = true, 
+	["for"] = true, 
+	["do"] = true, 
+	["function"] = true,
+	["_G"] = true,
+}
+
+local InvalidChars = {
+	[":"] = true,
+	["{"] = true,
+	["}"] = true,
+}
+
+function safer_lua:check(text, label, err_clbk)
+	local lToken = self:scanner(text)
+	local lineno = 0
+	local errno = 0
+	for _,token in ipairs(lToken) do
+		if type(token) == "number" then
+			lineno = token
+		elseif InvalidKeywords[token] then
+			err_clbk(label..lineno..": Invalid keyword '"..token.."'")
+			errno = errno + 1
+		elseif InvalidChars[token] then
+			err_clbk(label..lineno..": Invalid character '"..token.."'")
+			errno = errno + 1
+		end
+	end
+	return errno
+end

safer_lua/store.lua

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+safer_lua.StoreHelp = [[
+ Store - a secure shell over the LUA table type.
+ 
+ For records: 
+   tbl = Store()          --> {}
+   tbl.set(key,value)  --> {key=value}
+   tbl.get(key)           --> value
+   
+ 'key' can be a number or string
+ 'value' can be number, string, boolean, or Store
+ Example: tbl.set("a","test")
+ 
+ For lists: 
+   tbl = Store(1,2,3,4)  --> {1,2,3,4}
+   tbl.insert(pos, value)   
+   tbl.remove(pos)   
+   
+ 'pos' must be a number
+ 
+ Methods:
+   tbl.set(key, value)   --> add/set a value
+   tbl.get(key)	           --> read a value
+   tbl.size()                 --> return the table size
+   tbl.insert(pos, value) --> insert into list   
+   tbl.remove(pos)       --> return and remove from list
+   tbl.sort()                   -- sort list
+   tbl.dump()               --> format as string (debugging)   
+]]
+
+function safer_lua.Store(...)
+
+    local new_t = {__data__ = {}}
+    local mt = {}
+	
+    -- `all` will represent the number of both
+    local Count = 0
+
+    mt.__newindex = function(t, k, v) return end
+	
+	mt.count = function(v)
+		if type(v) == "number" then
+			return 1
+		elseif type(v) == "boolean" then
+			return 1
+		elseif v == nil then
+			return 0
+		elseif type(v) == "string" then
+			return #v
+		elseif type(v) == "table" then
+			return v.size()
+		else
+			return nil
+		end
+	end
+	
+	for idx = 1,select('#',...) do
+		local v = select(idx,...)
+		local cnt = mt.count(v)
+		if cnt then
+			Count = Count + cnt
+			if Count < safer_lua.MaxTableSize then
+				rawset(new_t.__data__,idx, v)
+			end
+		end
+	end
+	
+	new_t.set = function(k,v)
+		if type(k) == "string" or type(k) == "number" then
+			Count = Count - mt.count(rawget(new_t.__data__, k))
+			local cnt = mt.count(v)
+			if cnt then
+				Count = Count + cnt
+				if Count < safer_lua.MaxTableSize then
+					rawset(new_t.__data__,k,v)
+				end
+			end
+		end
+	end
+ 
+	new_t.get = function(k)
+		return rawget(new_t.__data__, k)
+	end
+	
+	new_t.size = function(t)
+		return Count
+	end
+ 
+	new_t.insert = function(v, i)
+		local cnt = mt.count(v)
+		if cnt then
+			Count = Count + cnt
+			if i == nil then i = #new_t.__data__ + 1 end
+			if Count < safer_lua.MaxTableSize then
+				table.insert(new_t.__data__,i,v)
+			end
+		end
+	end
+	
+	new_t.remove = function(i)
+		local v = table.remove(new_t.__data__,i)
+		local cnt = mt.count(v)
+		Count = Count - cnt
+		return v
+	end
+	
+	new_t.sort = function()
+		table.sort(new_t.__data__)
+	end
+	
+	new_t.dump = function(size)
+		size = size or 200
+		local s = dump(new_t.__data__)
+		if #s > size then s = s:sub(1, size).."..." end
+		return s
+	end
+
+return setmetatable(new_t, mt)
+end

safer_lua/test_environ.lua

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+core = {}
+
+function core.global_exists(name)
+	return false
+end
+
+dofile('/home/joachim/minetest/builtin/common/vector.lua')
+dofile('/home/joachim/minetest/builtin/common/misc_helpers.lua')
+
+safer_lua = {}
+dofile('/home/joachim/minetest/mods/techpack/safer_lua/store.lua')
+dofile('/home/joachim/minetest/mods/techpack/safer_lua/scanner.lua')
+dofile('/home/joachim/minetest/mods/techpack/safer_lua/environ.lua')
+
+--local Cache = {}
+--local key = minetest.pos_to_hash(pos)
+--code = Cache[key]
+
+local function foo(self, val)
+	_G = self._G
+	print("Hallo", val)
+end	
+
+local function error(pos, s)
+	print("[Test] "..s)
+end
+
+local init = "init = 5"
+local loop = [[
+  $foo("hallo")
+  S.foo("hallo")
+  --S._G.print("Fehler")
+  $foo(math.floor(5.5))
+  $foo("Joe")
+  a = Store()
+  a.set("a", 123)
+  $foo(a.get("a"))  
+  $foo(ticks)  
+]]
+
+local env = {foo = foo}
+
+
+local code = safer_lua.init(0, init, loop, env, error)
+if code then
+	print(safer_lua.run_loop(0, code, error))
+	safer_lua.run_loop(0, code, error)
+	safer_lua.run_loop(0, code, error)
+end

safer_lua/test_scanner.lua

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+core = {}
+
+function core.global_exists(name)
+	return false
+end
+
+dofile('/home/joachim/minetest/builtin/common/vector.lua')
+dofile('/home/joachim/minetest/builtin/common/misc_helpers.lua')
+dofile('/home/joachim/minetest/mods/techpack/safer_lua/scanner.lua')
+
+code = [[
+-- GOOD
+a = 1
+a = a + 1
+print(a)
+foo(a)
+
+-- BAD
+_G.print(()
+t = {}
+for i = 1,1000 do
+]]
+
+local function error(s)
+	print("[Robbi] "..s)
+end
+
+safer_lua:check(code, "Code", error)

safer_lua/test_store.lua

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+core = {}
+
+function core.global_exists(name)
+	return false
+end
+
+dofile('/home/joachim/minetest/builtin/common/vector.lua')
+dofile('/home/joachim/minetest/builtin/common/misc_helpers.lua')
+
+safer_lua = {}
+safer_lua.MaxTableSize = 1000   -- number of table entries considering string lenghts
+
+dofile('/home/joachim/minetest/mods/techpack/safer_lua/store.lua')
+
+
+print("S1")
+local s1 = safer_lua.Store()
+assert(s1.size() == 0)
+
+s1.a = 3
+s1[1] = 4
+assert(s1.size() == 0)
+
+s1.set("b", "Hallo")
+assert(s1.size() == 5)
+
+assert(s1.get("b") == "Hallo")
+assert(s1.size() == 5)
+
+print("S2")
+local s2 = safer_lua.Store()
+assert(s2.size() == 0)
+s2.set("b", "Joe")
+assert(s2.size() == 3)
+
+assert(s2.b == nil)
+assert(s2.get('b') == "Joe")
+s2.c = "XXX!"
+assert(s2.c == nil)
+
+s1.set("c", s2)
+print(dump(s1.get("c")))
+
+print("S3")
+local s3 = safer_lua.Store(1,2,3,4)
+assert(s3.size() == 4)
+print(dump(s3))
+
+s3.insert(0, 1)
+s3.insert(5)
+print(s3.dump())
+print(s2.dump())
+
+s2.set("s2", s2)
+print(s2.dump())
+
+print(dump(s2))

sl_controller/commands.lua

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+--[[
+
+	sl_controller
+	=============
+
+	Copyright (C) 2018 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	commands.lua:
+	
+	Register all basic controller commands
+
+]]--
+
+sl_controller.register_function("get_input", {
+	cmnd = function(self, num)
+		_G = self._G
+		return sl_controller.get_input(self.meta.number, num)
+	end,
+	help = " $get_input(num)  --> 'on', 'off', or nil\n"..
+		" Read local input value from device with number 'num'.\n"..
+		' example: inp = $get_input("1234")\n'..
+		" The device has to be connected with the controller."
+})
+
+sl_controller.register_function("get_status", {
+	cmnd = function(self, num) 
+		_G = self._G
+		return tubelib.send_request(num, "state", nil)
+	end,
+	help = " $get_status(num)  --> 'stopped', 'running',\n"..
+		" 'standby', 'blocked' or 'fault'\n"..
+		" Read status from a remote device.\n"..
+		' example: sts = $get_status("1234")'
+})
+
+sl_controller.register_function("time_as_str", {
+	cmnd = function(self) 
+		_G = self._G
+		local t = minetest.get_timeofday()
+		local h = math.floor(t*24) % 24
+		local m = math.floor(t*1440) % 60
+		return string.format("%02d:%02d", h, m)
+	end,
+	help = " $time_as_str()  --> e.g. '18:45'\n"..
+		" Read time of day as string (24h).\n"..
+		' example: time = $time_as_str()'
+})
+
+sl_controller.register_function("time_as_num", {
+	cmnd = function(self, num) 
+		_G = self._G
+		local t = minetest.get_timeofday()
+		local h = math.floor(t*24) % 24
+		local m = math.floor(t*1440) % 60
+		return h * 100 + m
+	end,
+	help = " $time_as_num()  --> e.g.: 1845\n"..
+		" Read time of day as number (24h).\n"..
+		' example: time = $time_as_num()'
+})
+
+sl_controller.register_function("playerdetector", {
+	cmnd = function(self, num) 
+		_G = self._G
+		return tubelib.send_request(num, "name", nil)
+	end,
+	help = " $playerdetector(num) --> e.g. 'Joe'\n"..
+		" '' is returned if no layer is nearby.\n"..
+		' example: name = $playerdetector("1234")'
+})
+
+sl_controller.register_action("send_cmnd", {
+	cmnd = function(self, num, text) 
+		_G = self._G
+		tubelib.send_message(num, self.meta.owner, nil, text, nil)
+	end,
+	help = " $send_cmnd(num, text)\n"..
+		" Send a command to the device with number 'num'.\n"..
+		" For most devices: 'on', 'off'\n"..
+		" Signal Tower: 'green', 'amber', 'red'\n"..
+		' example: $send_cmnd("1234", "on")'
+})
+
+sl_controller.register_action("display", {
+	cmnd = function(self, num, row, text1, text2, text3)
+		_G = self._G
+		local text = (text1 or "") .. (text2 or "") .. (text3 or "")
+		tubelib.send_message(num, self.meta.owner, nil, "row", {row = row, str = text})
+	end,
+	help = " $display(num, row, text,...)\n"..
+		" Send a text line to the display with number 'num'.\n"..
+		" 'row' is a value from 1..9\n"..
+		" The function accepts up to 3 text parameters\n"..
+		' example: $display("0123", 1, "Hello ", name, " !")'
+})
+
+sl_controller.register_action("clear_screen", {
+	cmnd = function(self, num) 
+		_G = self._G
+		tubelib.send_message(num, self.meta.owner, nil, "clear", nil)
+	end,
+	help = " $clear_screen(num)\n"..
+		" Clear the screen of the display\n"..
+		" with number 'num'.\n"..
+		' example: $clear_screen("1234")'
+})
+
+sl_controller.register_action("chat", {
+	cmnd = function(self, text) 
+		_G = self._G
+		minetest.chat_send_player(self.meta.owner, "[SmartLine Controller] "..text)
+	end,
+	help =  " $chat(text)\n"..
+		" Send yourself a chat message.\n"..
+		' example: $chat("Hello")'
+})
+
+sl_controller.register_action("door", {
+	cmnd = function(self, pos, text) 
+		_G = self._G
+		pos = minetest.string_to_pos("("..pos..")")
+		if pos then
+			local door = doors.get(pos)
+			if door then
+				local player = {
+					get_player_name = function() return self.meta.owner end,
+				}
+				if state == "open" then
+					door:open(player)
+				elseif state == "close" then
+					door:close(player)
+				end
+			end
+		end
+	end,
+	help =  " %door(pos, text)\n"..
+		" Open/Close a door at position 'pos'\n"..
+		' example: door("123,7,-1200", "close")\n'..
+		" Hint: Use the Tubelib Programmer to\ndetermine the door position."
+})

sl_controller/controller.lua

@@ -0,0 +1,371 @@
+--[[
+
+	sl_controller
+	=============
+
+	Copyright (C) 2018 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+	controller.lua:
+
+]]--
+
+local sHELP = [[Safer LUA Controller
+
+Safer LUA is a subset of LUA with the following restrictions:
+ - No loop keywords like: for, while, repeat,...
+ - No table constructions via: { ... }
+ - Limited set of available functions 
+ - Store() as alternative to LUA tables
+
+]]
+
+local mail_exists = minetest.get_modpath("mail") and mail ~= nil
+ 
+sl_controller = {}
+
+local Cache = {}
+
+local tCommands = {}
+local tFunctions = {" Overview", " Store"}
+local tHelpTexts = {[" Overview"] = sHELP, [" Store"] = safer_lua.StoreHelp}
+local sFunctionList = ""
+local tFunctionIndex = {}
+
+minetest.after(2, function() 
+	sFunctionList = table.concat(tFunctions, ",") 
+	for idx,key in ipairs(tFunctions) do
+		tFunctionIndex[key] = idx
+	end
+end)
+
+local function output(pos, text)
+	local meta = minetest.get_meta(pos)
+	text = meta:get_string("output") .. "\n" .. (text or "")
+	text = text:sub(-500,-1)
+	meta:set_string("output", text)
+end
+
+--
+-- API functions for function/action registrations
+--
+function sl_controller.register_function(key, attr)
+	tCommands[key] = attr.cmnd
+	table.insert(tFunctions, " $"..key)
+	tHelpTexts[" $"..key] = attr.help
+end
+
+function sl_controller.register_action(key, attr)
+	tCommands[key] = attr.cmnd
+	table.insert(tFunctions, " $"..key)
+	tHelpTexts[" $"..key] = attr.help
+end
+
+local function merge(dest, keys, values)
+  for idx,key in ipairs(keys) do
+    dest.env[key] = values[idx]
+  end
+  return dest
+end
+
+sl_controller.register_action("print", {
+	cmnd = function(self, text1, text2, text3)
+		_G = self._G
+		local pos = self.meta.pos
+		local text = (text1 or "")..(text2 or "")..(text3 or "")
+		output(pos, text)
+	end,
+	help = "$print(text,...)\n"..
+		"Send a text line to the output window.\n"..
+		"The function accepts up to 3 text strings\n"..
+		'e.g. $print("Hello ", name, " !")'
+})
+
+
+local function formspec1(meta)
+	local running = meta:get_int("state") == tubelib.RUNNING
+	local cmnd = running and "stop;Stop" or "start;Start" 
+	local init = meta:get_string("init")
+	init = minetest.formspec_escape(init)
+	return "size[10,8]"..
+	default.gui_bg..
+	default.gui_bg_img..
+	default.gui_slots..
+	"tabheader[0,0;tab;init,loop,outp,notes,help;1;;true]"..
+	"textarea[0.3,0.2;10,8.3;init;function init();"..init.."]"..
+	"label[0,7.3;end]"..
+	"button_exit[4.4,7.5;1.8,1;cancel;Cancel]"..
+	"button[6.3,7.5;1.8,1;save;Save]"..
+	"button[8.2,7.5;1.8,1;"..cmnd.."]"
+end
+
+local function formspec2(meta)
+	local running = meta:get_int("state") == tubelib.RUNNING
+	local cmnd = running and "stop;Stop" or "start;Start"
+	local loop = meta:get_string("loop")
+	loop = minetest.formspec_escape(loop)
+	return "size[10,8]"..
+	default.gui_bg..
+	default.gui_bg_img..
+	default.gui_slots..
+	"tabheader[0,0;tab;init,loop,outp,notes,help;2;;true]"..
+	"textarea[0.3,0.2;10,8.3;loop;function loop(ticks, elapsed);"..loop.."]"..
+	"label[0,7.3;end]"..
+	"button_exit[4.4,7.5;1.8,1;cancel;Cancel]"..
+	"button[6.3,7.5;1.8,1;save;Save]"..
+	"button[8.2,7.5;1.8,1;"..cmnd.."]"
+end
+
+local function formspec3(meta)
+	local running = meta:get_int("state") == tubelib.RUNNING
+	local cmnd = running and "stop;Stop" or "start;Start" 
+	local output = meta:get_string("output")
+	output = minetest.formspec_escape(output)
+	return "size[10,8]"..
+	default.gui_bg..
+	default.gui_bg_img..
+	default.gui_slots..
+	"tabheader[0,0;tab;init,loop,outp,notes,help;3;;true]"..
+	"textarea[0.3,0.2;10,8.3;help;Output:;"..output.."]"..
+	"button[4.4,7.5;1.8,1;clear;Clear]"..
+	"button[6.3,7.5;1.8,1;update;Update]"..
+	"button[8.2,7.5;1.8,1;"..cmnd.."]"
+end
+
+local function formspec4(meta)
+	local notes = meta:get_string("notes")
+	notes = minetest.formspec_escape(notes)
+	return "size[10,8]"..
+	default.gui_bg..
+	default.gui_bg_img..
+	default.gui_slots..
+	"tabheader[0,0;tab;init,loop,outp,notes,help;4;;true]"..
+	"textarea[0.3,0.2;10,8.3;notes;Notepad:;"..notes.."]"..
+	"button_exit[6.3,7.5;1.8,1;cancel;Cancel]"..
+	"button[8.2,7.5;1.8,1;save;Save]"
+end
+
+local function formspec5(items, pos, text)
+	text = minetest.formspec_escape(text)
+	return "size[10,8]"..
+	default.gui_bg..
+	default.gui_bg_img..
+	default.gui_slots..
+	"tabheader[0,0;tab;init,loop,outp,notes,help;5;;true]"..
+	"label[0,-0.2;Functions:]"..
+	"dropdown[0.3,0.2;10,8.3;functions;"..items..";"..pos.."]"..
+	"textarea[0.3,1.3;10,8;help;Help:;"..text.."]"
+end
+
+local function error(pos, err)
+	output(pos, err)
+	local meta = minetest.get_meta(pos)
+	local number = meta:get_string("number")
+	meta:set_string("infotext", "Controller "..number..": error")
+	return false
+end
+
+local function compile(pos, meta, number)
+	local init = meta:get_string("init")
+	local loop = meta:get_string("loop")
+	local owner = meta:get_string("owner")
+	local env = table.copy(tCommands)
+	env.meta = {pos=pos, owner=owner, number=number}
+	local code = safer_lua.init(pos, init, loop, env, error)
+	
+	if code then
+		Cache[number] = {code=code, inputs={}}
+		return true
+	end
+	return false
+end
+
+local function on_timer(pos, elapsed)
+	local t = minetest.get_us_time()
+	local meta = minetest.get_meta(pos)
+	local number = meta:get_string("number")
+	if Cache[number] or compile(pos, meta, number) then
+		
+		local code = Cache[number].code
+		local res = safer_lua.run_loop(pos, elapsed, code, error)
+		
+		t = minetest.get_us_time() - t
+		print("time", t)
+		return res
+	end
+	return false
+end
+
+local function start_controller(pos)
+	local meta = minetest.get_meta(pos)
+	local number = meta:get_string("number")
+	if compile(pos, meta, number) then
+		meta:set_int("state", tubelib.RUNNING)
+		minetest.get_node_timer(pos):start(1)
+		meta:set_string("infotext", "Controller "..number..": running")
+	end
+	meta:set_string("output", "<press update>")
+	meta:set_string("formspec", formspec3(meta))
+end
+
+local function stop_controller(pos)
+	local meta = minetest.get_meta(pos)
+	local number = meta:get_string("number")
+	meta:set_int("state", tubelib.STOPPED)
+	minetest.get_node_timer(pos):stop()
+	meta:set_string("infotext", "Controller "..number..": stopped")
+	meta:set_string("formspec", formspec2(meta))
+end
+
+local function on_receive_fields(pos, formname, fields, player)
+	if minetest.is_protected(pos, player:get_player_name()) then
+		return
+	end
+	local meta = minetest.get_meta(pos)
+	
+	--print(dump(fields))
+	if fields.cancel == nil then
+		if fields.init then
+			meta:set_string("init", fields.init)
+			meta:set_string("formspec", formspec1(meta))
+		elseif fields.loop then
+			meta:set_string("loop", fields.loop)
+			meta:set_string("formspec", formspec2(meta))
+		elseif fields.notes then
+			meta:set_string("notes", fields.notes)
+			meta:set_string("formspec", formspec4(meta))
+		end	
+	end
+	
+	if fields.update then
+		meta:set_string("formspec", formspec3(meta))
+	elseif fields.clear then
+		meta:set_string("output", "<press update>")
+		meta:set_string("formspec", formspec3(meta))
+	elseif fields.tab == "1" then
+		meta:set_string("formspec", formspec1(meta))
+	elseif fields.tab == "2" then
+		meta:set_string("formspec", formspec2(meta))
+	elseif fields.tab == "3" then
+		meta:set_string("formspec", formspec3(meta))
+	elseif fields.tab == "4" then
+		meta:set_string("formspec", formspec4(meta))
+	elseif fields.tab == "5" then
+		meta:set_string("formspec", formspec5(sFunctionList, 1, sHELP))
+	elseif fields.start == "Start" then
+		start_controller(pos)
+	elseif fields.stop == "Stop" then
+		stop_controller(pos)
+	elseif fields.functions then
+		local key = fields.functions
+		local text = tHelpTexts[key] or ""
+		local pos = tFunctionIndex[key] or 1
+		meta:set_string("formspec", formspec5(sFunctionList, pos, text))
+	end
+end
+
+minetest.register_node("sl_controller:controller", {
+	description = "SaferLUA Controller",
+	inventory_image = "sl_controller_inventory.png",
+	wield_image = "sl_controller_inventory.png",
+	stack_max = 1,
+	tiles = {
+		-- up, down, right, left, back, front
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png",
+		"smartline.png^sl_controller.png",
+	},
+
+	drawtype = "nodebox",
+	node_box = {
+		type = "fixed",
+		fixed = {
+			{ -6/32, -6/32, 14/32,  6/32,  6/32, 16/32},
+		},
+	},
+	
+	after_place_node = function(pos, placer)
+		local meta = minetest.get_meta(pos)
+		local number = tubelib.add_node(pos, "sl_controller:controller")
+		meta:set_string("owner", placer:get_player_name())
+		--print("after_place_node", number)
+		meta:set_string("number", number)
+		meta:set_int("state", tubelib.STOPPED)
+		meta:set_string("init", "-- called only once")
+		meta:set_string("loop", "-- called every second")
+		meta:set_string("notes", "For your notes / snippets")
+		meta:set_string("formspec", formspec1(meta))
+		meta:set_string("infotext", "Controller "..number..": stopped")
+	end,
+
+	on_receive_fields = on_receive_fields,
+	
+	on_dig = function(pos, node, puncher, pointed_thing)
+		if minetest.is_protected(pos, puncher:get_player_name()) then
+			return
+		end
+		
+		minetest.node_dig(pos, node, puncher, pointed_thing)
+		tubelib.remove_node(pos)
+	end,
+	
+	on_timer = on_timer,
+	
+	paramtype = "light",
+	sunlight_propagates = true,
+	paramtype2 = "facedir",
+	groups = {choppy=1, cracky=1, crumbly=1},
+	is_ground_content = false,
+	sounds = default.node_sound_stone_defaults(),
+})
+
+
+minetest.register_craft({
+	type = "shapeless",
+	output = "sl_controller:controller",
+	recipe = {"smartline:controller"}
+})
+
+
+local function set_input(number, input, val)
+	if input then 
+		if Cache[number] and Cache[number].inputs then
+			--print("set_input", input, val)
+			Cache[number].inputs[input] = val
+		end
+	end
+end	
+
+function sl_controller.get_input(number, input)
+	--print("get_input", number, input, dump(Cache[number].inputs))
+	if input then 
+		if Cache[number] and Cache[number].inputs then
+			return Cache[number].inputs[input] or "off"
+		end
+	end
+	return "off"
+end	
+
+tubelib.register_node("sl_controller:controller", {}, {
+	on_recv_message = function(pos, topic, payload)
+		-----------------------------------------------------
+		local meta = minetest.get_meta(pos)
+		local number = meta:get_string("number")
+		---------------------------------------------
+		if topic == "on" then
+			set_input(number, payload, topic)
+		elseif topic == "off" then
+			set_input(number, payload, topic)
+		elseif topic == "state" then
+			local state = meta:get_int("state")
+			return tubelib.statestring(state)
+		else
+			return "unsupported"
+		end
+	end,
+})		

sl_controller/depends.txt

@@ -0,0 +1,5 @@
+default
+doors
+tubelib
+safer_lua
+

sl_controller/description.txt

@@ -0,0 +1,2 @@
+tbd.
+

sl_controller/init.lua

@@ -0,0 +1,14 @@
+--[[
+
+	sl_controller
+	=============
+	
+	Copyright (C) 2018 Joachim Stolberg
+
+	LGPLv2.1+
+	See LICENSE.txt for more information
+
+]]--
+
+dofile(minetest.get_modpath("sl_controller") .. "/controller.lua")
+dofile(minetest.get_modpath("sl_controller") .. "/commands.lua")

sl_controller/mod.conf

@@ -0,0 +1 @@
+name=sl_controller