minetest-mm/mods/advtrains/advtrains_luaautomation/environment.lua
2021-11-06 16:01:45 +01:00

372 lines
10 KiB
Lua

-------------
-- lua sandboxed environment
-- function to cross out functions and userdata.
-- modified from dump()
function atlatc.remove_invalid_data(o, nested)
if o==nil then return nil end
local valid_dt={["nil"]=true, boolean=true, number=true, string=true}
if type(o) ~= "table" then
--check valid data type
if not valid_dt[type(o)] then
return nil
end
return o
end
-- Contains table -> true/nil of currently nested tables
nested = nested or {}
if nested[o] then
return nil
end
nested[o] = true
for k, v in pairs(o) do
v = atlatc.remove_invalid_data(v, nested)
end
nested[o] = nil
return o
end
local env_proto={
load = function(self, envname, data)
self.name=envname
self.sdata=data.sdata and atlatc.remove_invalid_data(data.sdata) or {}
self.fdata={}
self.init_code=data.init_code or ""
self.subscribers=data.subscribers or {}
end,
save = function(self)
-- throw any function values out of the sdata table
self.sdata = atlatc.remove_invalid_data(self.sdata)
return {sdata = self.sdata, init_code=self.init_code, subscribers=self.subscribers}
end,
}
--Environment
--Code modified 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_date(f, t)
if not f then
-- fall back to old behavior
return(os.date("*t",os.time()))
else
--pass parameters
return os.date(f,t)
end
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 > 2000 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.
-- Note: Disabled security since there are enough security leaks and this would be unneccessary anyway to DoS the server
local function safe_string_find(...)
--if (select(4, ...)) ~= true then
-- debug.sethook() -- Clear hook
-- error("string.find: 'plain' (fourth parameter) must always be true for security reasons.")
--end
return string.find(...)
end
local mp=minetest.get_modpath("advtrains_luaautomation")
local static_env = {
--core LUA functions
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,
date = safe_date,
},
POS = function(x,y,z) return {x=x, y=y, z=z} end,
getstate = advtrains.getstate,
setstate = advtrains.setstate,
is_passive = advtrains.is_passive,
--interrupts are handled per node, position unknown. (same goes for digilines)
--however external interrupts can be set here.
interrupt_pos = function(parpos, imesg)
local pos=atlatc.pcnaming.resolve_pos(parpos, "interrupt_pos")
atlatc.interrupt.add(0, pos, {type="ext_int", ext_int=true, message=imesg})
end,
-- sends an atc command to train regardless of where it is in the world
atc_send_to_train = function(train_id, command)
assertt(command, "string")
local train = advtrains.trains[train_id]
if train then
advtrains.atc.train_set_command(train, command, true)
return true
else
return false
end
end,
}
-- If interlocking is present, enable route setting functions
if advtrains.interlocking then
local function gen_checks(signal, route_name, noroutesearch)
assertt(route_name, "string")
local pos = atlatc.pcnaming.resolve_pos(signal)
local sigd = advtrains.interlocking.db.get_sigd_for_signal(pos)
if not sigd then
error("There's no signal at "..minetest.pos_to_string(pos))
end
local tcbs = advtrains.interlocking.db.get_tcbs(sigd)
if not tcbs then
error("Inconsistent configuration, no tcbs for signal at "..minetest.pos_to_string(pos))
end
local routeid, route
if not noroutesearch then
for routeidt, routet in ipairs(tcbs.routes) do
if routet.name == route_name then
routeid = routeidt
route = routet
break
end
end
if not route then
error("No route called "..route_name.." at "..minetest.pos_to_string(pos))
end
end
return pos, sigd, tcbs, routeid, route
end
static_env.can_set_route = function(signal, route_name)
local pos, sigd, tcbs, routeid, route = gen_checks(signal, route_name)
-- if route is already set on signal, return whether it's committed
if tcbs.routeset == routeid then
return tcbs.route_committed
end
-- actually try setting route (parameter 'true' designates try-run
local ok = advtrains.interlocking.route.set_route(sigd, route, true)
return ok
end
static_env.set_route = function(signal, route_name)
local pos, sigd, tcbs, routeid, route = gen_checks(signal, route_name)
return advtrains.interlocking.route.update_route(sigd, tcbs, routeid)
end
static_env.cancel_route = function(signal)
local pos, sigd, tcbs, routeid, route = gen_checks(signal, "", true)
return advtrains.interlocking.route.update_route(sigd, tcbs, nil, true)
end
static_env.get_aspect = function(signal)
local pos = atlatc.pcnaming.resolve_pos(signal)
return advtrains.interlocking.signal_get_aspect(pos)
end
static_env.set_aspect = function(signal, asp)
local pos = atlatc.pcnaming.resolve_pos(signal)
return advtrains.interlocking.signal_set_aspect(pos)
end
end
-- Lines-specific:
if advtrains.lines then
local atlrwt = advtrains.lines.rwt
static_env.rwt = {
now = atlrwt.now,
new = atlrwt.new,
copy = atlrwt.copy,
to_table = atlrwt.to_table,
to_secs = atlrwt.to_secs,
to_string = atlrwt.to_string,
add = atlrwt.add,
diff = atlrwt.diff,
sub = atlrwt.sub,
adj_diff = atlrwt.adj_diff,
adjust_cycle = atlrwt.adjust_cycle,
adjust = atlrwt.adjust,
to_string = atlrwt.to_string,
get_time_until = atlrwt.get_time_until,
next_rpt = atlrwt.next_rpt,
last_rpt = atlrwt.last_rpt,
time_from_last_rpt = atlrwt.time_from_last_rpt,
time_to_next_rpt = atlrwt.time_to_next_rpt,
}
end
for _, name in pairs(safe_globals) do
static_env[name] = _G[name]
end
--The environment all code calls get is a table that has set static_env as metatable.
--In general, every variable is local to a single code chunk, but kept persistent over code re-runs. Data is also saved, but functions and userdata and circular references are removed
--Init code and step code's environments are not saved
-- S - Table that can contain any save data global to the environment. Will be saved statically. Can't contain functions or userdata or circular references.
-- F - Table global to the environment, can contain volatile data that is deleted when server quits.
-- The init code should populate this table with functions and other definitions.
local proxy_env={}
--proxy_env gets a new metatable in every run, but is the shared environment of all functions ever defined.
-- returns: true, fenv if successful; nil, error if error
function env_proto:execute_code(localenv, code, evtdata, customfct)
-- create us a print function specific for this environment
if not self.safe_print_func then
local myenv = self
self.safe_print_func = function(...)
myenv:log("info", ...)
end
end
local metatbl ={
__index = function(t, i)
if i=="S" then
return self.sdata
elseif i=="F" then
return self.fdata
elseif i=="event" then
return evtdata
elseif customfct and customfct[i] then
return customfct[i]
elseif localenv and localenv[i] then
return localenv[i]
elseif i=="print" then
return self.safe_print_func
end
return static_env[i]
end,
__newindex = function(t, i, v)
if i=="S" or i=="F" or i=="event" or (customfct and customfct[i]) or static_env[i] then
debug.sethook()
error("Trying to overwrite environment contents")
end
localenv[i]=v
end,
}
setmetatable(proxy_env, metatbl)
local fun, err=loadstring(code)
if not fun then
return false, err
end
setfenv(fun, proxy_env)
local succ, data = pcall(fun)
if succ then
data=localenv
end
return succ, data
end
function env_proto:run_initcode()
if self.init_code and self.init_code~="" then
local old_fdata=self.fdata
self.fdata = {}
--atprint("[atlatc]Running initialization code for environment '"..self.name.."'")
local succ, err = self:execute_code({}, self.init_code, {type="init", init=true})
if not succ then
self:log("error", "Executing InitCode for '"..self.name.."' failed:"..err)
self.init_err=err
if old_fdata then
self.fdata=old_fdata
self:log("warning", "The 'F' table has been restored to the previous state.")
end
end
end
end
-- log to environment subscribers. severity can be "error", "warning" or "info" (used by internal print)
function env_proto:log(severity, ...)
local text=advtrains.print_concat_table({"[atlatc "..self.name.." "..severity.."]", ...})
minetest.log("action", text)
for _, pname in ipairs(self.subscribers) do
minetest.chat_send_player(pname, text)
end
end
-- env.subscribers table may be directly altered by callers.
--- class interface
function atlatc.env_new(name)
local newenv={
name=name,
init_code="",
sdata={},
subscribers={},
}
setmetatable(newenv, {__index=env_proto})
return newenv
end
function atlatc.env_load(name, data)
local newenv={}
setmetatable(newenv, {__index=env_proto})
newenv:load(name, data)
return newenv
end
function atlatc.run_initcode()
for envname, env in pairs(atlatc.envs) do
env:run_initcode()
end
end