1 files changed, 166 insertions, 0 deletions
diff --git a/advtrains/advtrains/lua_atc.lua b/advtrains/advtrains/lua_atc.lua
new file mode 100644
index 0000000..313d70d
--- /dev/null
+++ b/advtrains/advtrains/lua_atc.lua
@@ -0,0 +1,166 @@
+-------------
+--LUA ATC controllers
+
+local latc={}
+
+function latc.load_data(data)
+end
+function latc.save_data()
+	return stuff
+end
+
+latc.data
+latc.env_cdata
+latc.init_code=""
+latc.step_code=""
+
+advtrains.fpath_latc=minetest.get_worldpath().."/advtrains_latc"
+local file, err = io.open(advtrains.fpath_atc, "r")
+if not file then
+	local er=err or "Unknown Error"
+	atprint("Failed loading advtrains latc save file "..er)
+else
+	local tbl = minetest.deserialize(file:read("*a"))
+	if type(tbl) == "table" then
+		atc.controllers=tbl.controllers
+	end
+	file:close()
+end
+function latc.save()
+	
+	local datastr = minetest.serialize({controllers = atc.controllers})
+	if not datastr then
+		minetest.log("error", " Failed to serialize latc data!")
+		return
+	end
+	local file, err = io.open(advtrains.fpath_atc, "w")
+	if err then
+		return err
+	end
+	file:write(datastr)
+	file:close()
+end
+
+--Privilege
+--Only trusted players should be enabled to build stuff which can break the server.
+--If I later decide to have multiple environments ('data' tables), I better store an owner for every controller for future reference.
+
+minetest.register_privilege("advtrains_lua_atc", { description = "Player can place and modify LUA ATC components. Grant with care! Allows to execute bad LUA code.", give_to_singleplayer = false, default= false })
+
+--Environment
+--Code from mesecons_luacontroller (credit goes to Jeija and mesecons contributors)
+
+local safe_globals = {
+	"assert", "error", "ipairs", "next", "pairs", "select",
+	"tonumber", "tostring", "type", "unpack", "_VERSION"
+}
+local function safe_print(param)
+	print(dump(param))
+end
+
+local function safe_date()
+	return(os.date("*t",os.time()))
+end
+
+-- string.rep(str, n) with a high value for n can be used to DoS
+-- the server. Therefore, limit max. length of generated string.
+local function safe_string_rep(str, n)
+	if #str * n > mesecon.setting("luacontroller_string_rep_max", 64000) then
+		debug.sethook() -- Clear hook
+		error("string.rep: string length overflow", 2)
+	end
+
+	return string.rep(str, n)
+end
+
+-- string.find with a pattern can be used to DoS the server.
+-- Therefore, limit string.find to patternless matching.
+local function safe_string_find(...)
+	if (select(4, ...)) ~= true then
+		debug.sethook() -- Clear hook
+		error("string.find: 'plain' (fourth parameter) must always be true in a LuaController")
+	end
+
+	return string.find(...)
+end
+
+latc.static_env = {
+	print = safe_print,
+	string = {
+		byte = string.byte,
+		char = string.char,
+		format = string.format,
+		len = string.len,
+		lower = string.lower,
+		upper = string.upper,
+		rep = safe_string_rep,
+		reverse = string.reverse,
+		sub = string.sub,
+		find = safe_string_find,
+	},
+	math = {
+		abs = math.abs,
+		acos = math.acos,
+		asin = math.asin,
+		atan = math.atan,
+		atan2 = math.atan2,
+		ceil = math.ceil,
+		cos = math.cos,
+		cosh = math.cosh,
+		deg = math.deg,
+		exp = math.exp,
+		floor = math.floor,
+		fmod = math.fmod,
+		frexp = math.frexp,
+		huge = math.huge,
+		ldexp = math.ldexp,
+		log = math.log,
+		log10 = math.log10,
+		max = math.max,
+		min = math.min,
+		modf = math.modf,
+		pi = math.pi,
+		pow = math.pow,
+		rad = math.rad,
+		random = math.random,
+		sin = math.sin,
+		sinh = math.sinh,
+		sqrt = math.sqrt,
+		tan = math.tan,
+		tanh = math.tanh,
+	},
+	table = {
+		concat = table.concat,
+		insert = table.insert,
+		maxn = table.maxn,
+		remove = table.remove,
+		sort = table.sort,
+	},
+	os = {
+		clock = os.clock,
+		difftime = os.difftime,
+		time = os.time,
+		datetable = safe_date,
+	},
+}
+latc.static_env._G = env
+
+for _, name in pairs(safe_globals) do
+	latc.static_env[name] = _G[name]
+end
+
+
+--The environment all code calls get is a proxy table with a metatable.
+--When an index is read:
+-- Look in static_env
+-- Look in volatile_env (user_written functions and userdata)
+-- Look in saved_env (everything that's not a function or userdata)
+--when an index is written:
+-- If in static_env, do not allow
+-- if function or userdata, volatile_env
+-- if table, see below
+-- else, save in saved_env
+
+
+
+advtrains.latc=latc