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dd3b06cfd80aa30dd439e06882c1281ec83c8b02
mesecons/mesecons_luacontroller/init.lua
gamemanj dd3b06cfd8 Allowed loops & fixed certain strings 
I've added a simple lexer to work out the correct places to add dummy
code, which fixes the problem mentioned in code_prohibited.
This means LuaControllers are no longer restricted to simple
conditionals, but should still be safe for server owners.
Furthermore, the lexer prevents accidentally matching text in strings.
2015-11-14 11:48:55 +00:00

734 lines
20 KiB
Lua
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-- ______
-- |
-- |
-- | __ ___ _ __ _ _
-- | | | | | |\ | | |_| | | | | |_ |_|
-- |___| |______ |__| | \| | | \ |__| |_ |_ |_ |\
-- |
-- |
--
-- Reference
-- ports = get_real_port_states(pos): gets if inputs are powered from outside
-- newport = merge_port_states(state1, state2): just does result = state1 or state2 for every port
-- set_port(pos, rule, state): activates/deactivates the mesecons according to the port states
-- set_port_states(pos, ports): Applies new port states to a LuaController at pos
-- run(pos): runs the code in the controller at pos
-- reset_meta(pos, code, errmsg): performs a software-reset, installs new code and prints error messages
-- resetn(pos): performs a hardware reset, turns off all ports
--
-- The Sandbox
-- The whole code of the controller runs in a sandbox,
-- a very restricted environment.
-- However, as this does not prevent you from using e.g. loops,
-- we need to check for these prohibited commands first.
-- Actually the only way to damage the server is to
-- use too much memory from the sandbox.
-- You can add more functions to the environment
-- (see where local env is defined)
-- Something nice to play is is appending minetest.env to it.
local BASENAME = "mesecons_luacontroller:luacontroller"
local rules = {
a = {x = -1, y = 0, z = 0, name="A"},
b = {x = 0, y = 0, z = 1, name="B"},
c = {x = 1, y = 0, z = 0, name="C"},
d = {x = 0, y = 0, z = -1, name="D"},
}
------------------
-- Action stuff --
------------------
-- These helpers are required to set the port states of the luacontroller
local function update_real_port_states(pos, rule_name, new_state)
local meta = minetest.get_meta(pos)
if rule_name == nil then
meta:set_int("real_portstates", 1)
return
end
local n = meta:get_int("real_portstates") - 1
local L = {}
for i = 1, 4 do
L[i] = n % 2
n = math.floor(n / 2)
end
-- (0,-1) (-1,0) (1,0) (0,1)
local pos_to_side = { 4, 1, nil, 3, 2 }
if rule_name.x == nil then
for _, rname in ipairs(rule_name) do
local port = pos_to_side[rname.x + (2 * rname.z) + 3]
L[port] = (newstate == "on") and 1 or 0
end
else
local port = pos_to_side[rule_name.x + (2 * rule_name.z) + 3]
L[port] = (new_state == "on") and 1 or 0
end
meta:set_int("real_portstates",
1 +
1 * L[1] +
2 * L[2] +
4 * L[3] +
8 * L[4])
end
local port_names = {"a", "b", "c", "d"}
local function get_real_port_states(pos)
-- Determine if ports are powered (by itself or from outside)
local meta = minetest.get_meta(pos)
local L = {}
local n = meta:get_int("real_portstates") - 1
for _, name in ipairs(port_names) do
L[name] = ((n % 2) == 1)
n = math.floor(n / 2)
end
return L
end
local function merge_port_states(ports, vports)
return {
a = ports.a or vports.a,
b = ports.b or vports.b,
c = ports.c or vports.c,
d = ports.d or vports.d,
}
end
local function generate_name(ports)
local d = ports.d and 1 or 0
local c = ports.c and 1 or 0
local b = ports.b and 1 or 0
local a = ports.a and 1 or 0
return BASENAME..d..c..b..a
end
local function set_port(pos, rule, state)
if state then
mesecon.receptor_on(pos, {rule})
else
mesecon.receptor_off(pos, {rule})
end
end
local function clean_port_states(ports)
ports.a = ports.a and true or false
ports.b = ports.b and true or false
ports.c = ports.c and true or false
ports.d = ports.d and true or false
end
local function set_port_states(pos, ports)
local node = minetest.get_node(pos)
local name = node.name
clean_port_states(ports)
local vports = minetest.registered_nodes[name].virtual_portstates
local new_name = generate_name(ports)
if name ~= new_name and vports then
-- Problem:
-- We need to place the new node first so that when turning
-- off some port, it won't stay on because the rules indicate
-- there is an onstate output port there.
-- When turning the output off then, it will however cause feedback
-- so that the luacontroller will receive an "off" event by turning
-- its output off.
-- Solution / Workaround:
-- Remember which output was turned off and ignore next "off" event.
local meta = minetest.get_meta(pos)
local ign = minetest.deserialize(meta:get_string("ignore_offevents")) or {}
if ports.a and not vports.a and not mesecon.is_powered(pos, rules.a) then ign.A = true end
if ports.b and not vports.b and not mesecon.is_powered(pos, rules.b) then ign.B = true end
if ports.c and not vports.c and not mesecon.is_powered(pos, rules.c) then ign.C = true end
if ports.d and not vports.d and not mesecon.is_powered(pos, rules.d) then ign.D = true end
meta:set_string("ignore_offevents", minetest.serialize(ign))
minetest.swap_node(pos, {name = new_name, param2 = node.param2})
if ports.a ~= vports.a then set_port(pos, rules.a, ports.a) end
if ports.b ~= vports.b then set_port(pos, rules.b, ports.b) end
if ports.c ~= vports.c then set_port(pos, rules.c, ports.c) end
if ports.d ~= vports.d then set_port(pos, rules.d, ports.d) end
end
end
-----------------
-- Overheating --
-----------------
local function burn_controller(pos)
local node = minetest.get_node(pos)
node.name = BASENAME.."_burnt"
minetest.swap_node(pos, node)
minetest.get_meta(pos):set_string("lc_memory", "");
-- Wait for pending operations
minetest.after(0.2, mesecon.receptor_off, pos, mesecon.rules.flat)
end
local function overheat(pos, meta)
if mesecon.do_overheat(pos) then -- If too hot
burn_controller(pos)
return true
end
end
------------------------
-- Ignored off events --
------------------------
local function ignore_event(event, meta)
if event.type ~= "off" then return false end
local ignore_offevents = minetest.deserialize(meta:get_string("ignore_offevents")) or {}
if ignore_offevents[event.pin.name] then
ignore_offevents[event.pin.name] = nil
meta:set_string("ignore_offevents", minetest.serialize(ignore_offevents))
return true
end
end
-------------------------
-- Parsing and running --
-------------------------
local function safe_print(param)
print(dump(param))
end
local function remove_functions(x)
local tp = type(x)
if tp == "table" then
for key, value in pairs(x) do
local key_t, val_t = type(key), type(value)
if key_t == "function" or val_t == "function" then
x[key] = nil
else
if key_t == "table" then
remove_functions(key)
end
if val_t == "table" then
remove_functions(value)
end
end
end
elseif tp == "function" then
return nil
end
return x
end
local function get_interrupt(pos)
-- iid = interrupt id
local function interrupt(time, iid)
if type(time) ~= "number" then return end
local luac_id = minetest.get_meta(pos):get_int("luac_id")
mesecon.queue:add_action(pos, "lc_interrupt", {luac_id, iid}, time, iid, 1)
end
return interrupt
end
local function get_digiline_send(pos)
if not digiline then return end
return function(channel, msg)
minetest.after(0, function()
digiline:receptor_send(pos, digiline.rules.default, channel, msg)
end)
end
end
local safe_globals = {
"assert", "error", "ipairs", "next", "pairs", "pcall", "select",
"tonumber", "tostring", "type", "unpack", "_VERSION", "xpcall",
}
local function create_environment(pos, mem, event)
-- Gather variables for the environment
local vports = minetest.registered_nodes[minetest.get_node(pos).name].virtual_portstates
local vports_copy = {}
for k, v in pairs(vports) do vports_copy[k] = v end
local rports = get_real_port_states(pos)
-- Create new library tables on each call to prevent one LuaController
-- from breaking a library and messing up other LuaControllers.
local env = {
pin = merge_port_states(vports, rports),
port = vports_copy,
event = event,
mem = mem,
heat = minetest.get_meta(pos):get_int("heat"),
heat_max = mesecon.setting("overheat_max", 20),
print = safe_print,
interrupt = get_interrupt(pos),
digiline_send = get_digiline_send(pos),
string = {
byte = string.byte,
char = string.char,
format = string.format,
gsub = string.gsub,
len = string.len,
lower = string.lower,
upper = string.upper,
rep = string.rep,
reverse = string.reverse,
sub = string.sub,
},
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,
},
}
env._G = env
for _, name in pairs(safe_globals) do
env[name] = _G[name]
end
return env
end
local function timeout()
debug.sethook() -- Clear hook
error("Code timed out!")
end
--A VERY minimalistic lexer, does what it needs to for this job and no more.
--For now, block comments aren't implemented, but are detected.
local function lexLua(code)
local lexElements={}
--Find keywords, whitespace, strings, and then everything else is "unknownchar"
--Keywords and numbers.
function lexElements.keyword(str)
return str:match("^[%w_]+")
end
function lexElements.whitespace(str)
return str:match("^%s+")
end
--Unimplemented stuff goes here.
function lexElements.cleanup(str)
return str:match("^.+")
end
function lexElements.string(str)
--Now parse a string.
local quoteType=str:sub(1,1)
if quoteType~="\"" and quoteType~="\'" then return nil end
local inEscape=true
local rstr=""
for i=1,str:len() do
local c=str:sub(1,1)
if inEscape then
rstr=rstr..c
inEscape=false
else
if c==quoteType then return rstr..quoteType end
if c=="\\" then inEscape=true end
rstr=rstr..c
end
end
return nil --unfinished string
end
function lexElements.blockcomment(str)
local a=str:match("^--%[%[")
if not a then return nil end
local s=str:find("--%]%]")
if not s then return nil end
return str:sub(1,s+3)
end
function lexElements.linecomment(str)
return str:match("^--[^\r\n]+")
end
local lexElementsOrder={"keyword","whitespace","string","blockcomment","linecomment","cleanup"}
local lexResults={}
while code:len()>0 do
--Because break doesn't exist.
local function parseElem()
for _,v in ipairs(lexElementsOrder) do
local t,e=lexElements[v](code)
if t then
code=code:sub(t:len()+1)
table.insert(lexResults,{v,t})
return nil
end
if e then
return e
end
end
return "no match"
end
local err=parseElem()
if err then return nil,"Lexer Error:"..err..": "..code:sub(1,32) end
end
return lexResults
end
local function code_prohibited(code)
-- LuaJIT doesn't increment the instruction counter when running
-- loops, so we have to sanitize inputs if we're using LuaJIT.
if not jit then
return code
end
--Find the following constructs, and place dummies where (dummy) is:
--while ... do (dummy)
--for ... do (dummy)
--repeat (dummy)
-- This only exists in Lua 5.2
--(dummy) goto
local lexed,err=lexLua(code)
local rcode=""
if err then
return nil,"Couldn't lex code:"..err
end
for _,v in ipairs(lexed) do
--remove useless stuff since we're going over it anyway.
if v[1]=="whitespace" then v[2]="\r\n" end
if v[1]=="blockcomment" then v[2]="" end
if v[1]=="linecomment" then v[2]="" end
--Code injection so we can safely use every feature in Lua. The only purpose of the lexer is to filter stuff that would break this, really.
--(the old method would stop you from using keywords in strings.)
--You can also replace this with coroutine.yield, but that's best left to a computercraft-style mod.
local dummy="(function() end)()"
if v[2]=="do" then
v[2]="do "..dummy
end
if v[2]=="repeat" then
v[2]="repeat "..dummy
end
if v[2]=="goto" then
v[2]=dummy.." goto"
end
rcode=rcode..v[2]
end
return rcode
end
local function create_sandbox(code, env)
if code:byte(1) == 27 then
return nil, "Binary code prohibited."
end
local f, msg = loadstring(code)
if not f then return nil, msg end
setfenv(f, env)
return function(...)
debug.sethook(timeout, "", 10000)
local ok, ret = pcall(f, ...)
debug.sethook() -- Clear hook
if not ok then error(ret) end
return ret
end
end
local function load_memory(meta)
return minetest.deserialize(meta:get_string("lc_memory")) or {}
end
local function save_memory(pos, meta, mem)
local memstring = minetest.serialize(remove_functions(mem))
local memsize_max = mesecon.setting("luacontroller_memsize", 100000)
if (#memstring <= memsize_max) then
meta:set_string("lc_memory", memstring)
else
print("Error: Luacontroller memory overflow. "..memsize_max.." bytes available, "
..#memstring.." required. Controller overheats.")
burn_controller(pos)
end
end
local function run(pos, event)
local meta = minetest.get_meta(pos)
if overheat(pos) then return end
if ignore_event(event, meta) then return end
-- Load code & mem from meta
local mem = load_memory(meta)
local code = meta:get_string("code")
local err
code,err = code_prohibited(code)
if not code then return err end
-- Create environment
local env = create_environment(pos, mem, event)
-- Create the sandbox and execute code
local f, msg = create_sandbox(code, env)
if not f then return msg end
local success, msg = pcall(f)
if not success then return msg end
if type(env.port) ~= "table" then
return "Ports set are invalid."
end
-- Actually set the ports
set_port_states(pos, env.port)
-- Save memory. This may burn the luacontroller if a memory overflow occurs.
save_memory(pos, meta, env.mem)
end
mesecon.queue:add_function("lc_interrupt", function (pos, luac_id, iid)
-- There is no luacontroller anymore / it has been reprogrammed / replaced / burnt
if (minetest.get_meta(pos):get_int("luac_id") ~= luac_id) then return end
if (minetest.registered_nodes[minetest.get_node(pos).name].is_burnt) then return end
run(pos, {type="interrupt", iid = iid})
end)
local function reset_meta(pos, code, errmsg)
local meta = minetest.get_meta(pos)
meta:set_string("code", code)
code = minetest.formspec_escape(code or "")
errmsg = minetest.formspec_escape(errmsg or "")
meta:set_string("formspec", "size[10,8]"..
"background[-0.2,-0.25;10.4,8.75;jeija_luac_background.png]"..
"textarea[0.2,0.6;10.2,5;code;;"..code.."]"..
"image_button[3.75,6;2.5,1;jeija_luac_runbutton.png;program;]"..
"image_button_exit[9.72,-0.25;0.425,0.4;jeija_close_window.png;exit;]"..
"label[0.1,5;"..errmsg.."]")
meta:set_int("heat", 0)
meta:set_int("luac_id", math.random(1, 65535))
end
local function reset(pos)
set_port_states(pos, {a=false, b=false, c=false, d=false})
end
-----------------------
-- Node Registration --
-----------------------
local output_rules = {}
local input_rules = {}
local node_box = {
type = "fixed",
fixed = {
{-8/16, -8/16, -8/16, 8/16, -7/16, 8/16}, -- Bottom slab
{-5/16, -7/16, -5/16, 5/16, -6/16, 5/16}, -- Circuit board
{-3/16, -6/16, -3/16, 3/16, -5/16, 3/16}, -- IC
}
}
local selection_box = {
type = "fixed",
fixed = { -8/16, -8/16, -8/16, 8/16, -5/16, 8/16 },
}
local digiline = {
receptor = {},
effector = {
action = function(pos, node, channel, msg)
run(pos, {type = "digiline", channel = channel, msg = msg})
end
}
}
local function on_receive_fields(pos, form_name, fields)
if not fields.program then
return
end
reset(pos)
reset_meta(pos, fields.code)
local err = run(pos, {type="program"})
if err then
print(err)
reset_meta(pos, fields.code, err)
end
end
for a = 0, 1 do -- 0 = off 1 = on
for b = 0, 1 do
for c = 0, 1 do
for d = 0, 1 do
local cid = tostring(d)..tostring(c)..tostring(b)..tostring(a)
local node_name = BASENAME..cid
local top = "jeija_luacontroller_top.png"
if a == 1 then
top = top.."^jeija_luacontroller_LED_A.png"
end
if b == 1 then
top = top.."^jeija_luacontroller_LED_B.png"
end
if c == 1 then
top = top.."^jeija_luacontroller_LED_C.png"
end
if d == 1 then
top = top.."^jeija_luacontroller_LED_D.png"
end
local groups
if a + b + c + d ~= 0 then
groups = {dig_immediate=2, not_in_creative_inventory=1, overheat = 1}
else
groups = {dig_immediate=2, overheat = 1}
end
output_rules[cid] = {}
input_rules[cid] = {}
if a == 1 then table.insert(output_rules[cid], rules.a) end
if b == 1 then table.insert(output_rules[cid], rules.b) end
if c == 1 then table.insert(output_rules[cid], rules.c) end
if d == 1 then table.insert(output_rules[cid], rules.d) end
if a == 0 then table.insert( input_rules[cid], rules.a) end
if b == 0 then table.insert( input_rules[cid], rules.b) end
if c == 0 then table.insert( input_rules[cid], rules.c) end
if d == 0 then table.insert( input_rules[cid], rules.d) end
local mesecons = {
effector = {
rules = input_rules[cid],
action_change = function (pos, _, rule_name, new_state)
update_real_port_states(pos, rule_name, new_state)
run(pos, {type=new_state, pin=rule_name})
end,
},
receptor = {
state = mesecon.state.on,
rules = output_rules[cid]
}
}
minetest.register_node(node_name, {
description = "LuaController",
drawtype = "nodebox",
tiles = {
top,
"jeija_microcontroller_bottom.png",
"jeija_microcontroller_sides.png",
"jeija_microcontroller_sides.png",
"jeija_microcontroller_sides.png",
"jeija_microcontroller_sides.png"
},
inventory_image = top,
paramtype = "light",
groups = groups,
drop = BASENAME.."0000",
sunlight_propagates = true,
selection_box = selection_box,
node_box = node_box,
on_construct = reset_meta,
on_receive_fields = on_receive_fields,
sounds = default.node_sound_stone_defaults(),
mesecons = mesecons,
digiline = digiline,
-- Virtual portstates are the ports that
-- the node shows as powered up (light up).
virtual_portstates = {
a = a == 1,
b = b == 1,
c = c == 1,
d = d == 1,
},
after_dig_node = function (pos, node)
mesecon.receptor_off(pos, output_rules)
end,
is_luacontroller = true,
})
end
end
end
end
------------------------------
-- Overheated LuaController --
------------------------------
minetest.register_node(BASENAME .. "_burnt", {
drawtype = "nodebox",
tiles = {
"jeija_luacontroller_burnt_top.png",
"jeija_microcontroller_bottom.png",
"jeija_microcontroller_sides.png",
"jeija_microcontroller_sides.png",
"jeija_microcontroller_sides.png",
"jeija_microcontroller_sides.png"
},
inventory_image = "jeija_luacontroller_burnt_top.png",
is_burnt = true,
paramtype = "light",
groups = {dig_immediate=2, not_in_creative_inventory=1},
drop = BASENAME.."0000",
sunlight_propagates = true,
selection_box = selection_box,
node_box = node_box,
on_construct = reset_meta,
on_receive_fields = on_receive_fields,
sounds = default.node_sound_stone_defaults(),
virtual_portstates = {a = false, b = false, c = false, d = false},
mesecons = {
effector = {
rules = mesecon.rules.flat,
action_change = function(pos, _, rule_name, new_state)
update_real_port_states(pos, rule_name, new_state)
end,
},
},
})
------------------------
-- Craft Registration --
------------------------
minetest.register_craft({
output = BASENAME.."0000 2",
recipe = {
{'mesecons_materials:silicon', 'mesecons_materials:silicon', 'group:mesecon_conductor_craftable'},
{'mesecons_materials:silicon', 'mesecons_materials:silicon', 'group:mesecon_conductor_craftable'},
{'group:mesecon_conductor_craftable', 'group:mesecon_conductor_craftable', ''},
}
})
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