Rebase lua_tube onto upstream luacontroller

Adds:
 - various bug fixes
 - error label on the formspec
 - lightweight interrupts
This commit is contained in:
groxxda 2020-06-21 20:32:56 +00:00
parent 9eefe9c7bb
commit ee6c9991b9
1 changed files with 276 additions and 70 deletions

View File

@ -13,8 +13,10 @@
-- 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
-- run_inner(pos, code, event): runs code on the controller at pos and event
-- reset_formspec(pos, code, errmsg): installs new code and prints error messages, without resetting LCID
-- reset_meta(pos, code, errmsg): performs a software-reset, installs new code and prints error message
-- run(pos, event): a wrapper for run_inner which gets code & handles errors via reset_meta
-- resetn(pos): performs a hardware reset, turns off all ports
--
-- The Sandbox
@ -168,7 +170,7 @@ local function set_port_states(pos, ports)
-- 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 {}
local ign = minetest.deserialize(meta:get_string("ignore_offevents"), true) or {}
if ports.red and not vports.red and not mesecon.is_powered(pos, rules.red) then ign.red = true end
if ports.blue and not vports.blue and not mesecon.is_powered(pos, rules.blue) then ign.blue = true end
if ports.yellow and not vports.yellow and not mesecon.is_powered(pos, rules.yellow) then ign.yellow = true end
@ -214,7 +216,7 @@ end
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 {}
local ignore_offevents = minetest.deserialize(meta:get_string("ignore_offevents"), true) or {}
if ignore_offevents[event.pin.name] then
ignore_offevents[event.pin.name] = nil
meta:set_string("ignore_offevents", minetest.serialize(ignore_offevents))
@ -227,7 +229,11 @@ end
-------------------------
local function safe_print(param)
local string_meta = getmetatable("")
local sandbox = string_meta.__index
string_meta.__index = string -- Leave string sandbox temporarily
print(dump(param))
string_meta.__index = sandbox -- Restore string sandbox
end
local function safe_date()
@ -267,6 +273,7 @@ local function remove_functions(x)
local seen = {}
local function rfuncs(x)
if x == nil then return end
if seen[x] then return end
seen[x] = true
if type(x) ~= "table" then return end
@ -290,49 +297,174 @@ local function remove_functions(x)
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, "pipeworks:lc_tube_interrupt", {luac_id, iid}, time, iid, 1)
-- The setting affects API so is not intended to be changeable at runtime
local get_interrupt
if mesecon.setting("luacontroller_lightweight_interrupts", false) then
-- use node timer
get_interrupt = function(pos, itbl, send_warning)
return (function(time, iid)
if type(time) ~= "number" then error("Delay must be a number") end
if iid ~= nil then send_warning("Interrupt IDs are disabled on this server") end
table.insert(itbl, function() minetest.get_node_timer(pos):start(time) end)
end)
end
else
-- use global action queue
-- itbl: Flat table of functions to run after sandbox cleanup, used to prevent various security hazards
get_interrupt = function(pos, itbl, send_warning)
-- iid = interrupt id
local function interrupt(time, iid)
-- NOTE: This runs within string metatable sandbox, so don't *rely* on anything of the form (""):y
-- Hence the values get moved out. Should take less time than original, so totally compatible
if type(time) ~= "number" then error("Delay must be a number") end
table.insert(itbl, function ()
-- Outside string metatable sandbox, can safely run this now
local luac_id = minetest.get_meta(pos):get_int("luac_id")
-- Check if IID is dodgy, so you can't use interrupts to store an infinite amount of data.
-- Note that this is safe from alter-after-free because this code gets run after the sandbox has ended.
-- This runs outside of the timer and *shouldn't* harm perf. unless dodgy data is being sent in the first place
iid = remove_functions(iid)
local msg_ser = minetest.serialize(iid)
if #msg_ser <= mesecon.setting("luacontroller_interruptid_maxlen", 256) then
mesecon.queue:add_action(pos, "pipeworks:lc_tube_interrupt", {luac_id, iid}, time, iid, 1)
else
send_warning("An interrupt ID was too large!")
end
end)
end
return interrupt
end
end
-- Given a message object passed to digiline_send, clean it up into a form
-- which is safe to transmit over the network and compute its "cost" (a very
-- rough estimate of its memory usage).
--
-- The cleaning comprises the following:
-- 1. Functions (and userdata, though user scripts ought not to get hold of
-- those in the first place) are removed, because they break the model of
-- Digilines as a network that carries basic data, and they could exfiltrate
-- references to mutable objects from one Luacontroller to another, allowing
-- inappropriate high-bandwidth, no-wires communication.
-- 2. Tables are duplicated because, being mutable, they could otherwise be
-- modified after the send is complete in order to change what data arrives
-- at the recipient, perhaps in violation of the previous cleaning rule or
-- in violation of the message size limit.
--
-- The cost indication is only approximate; its not a perfect measurement of
-- the number of bytes of memory used by the message object.
--
-- Parameters:
-- msg -- the message to clean
-- back_references -- for internal use only; do not provide
--
-- Returns:
-- 1. The cleaned object.
-- 2. The approximate cost of the object.
local function clean_and_weigh_digiline_message(msg, back_references)
local t = type(msg)
if t == "string" then
-- Strings are immutable so can be passed by reference, and cost their
-- length plus the size of the Lua object header (24 bytes on a 64-bit
-- platform) plus one byte for the NUL terminator.
return msg, #msg + 25
elseif t == "number" then
-- Numbers are passed by value so need not be touched, and cost 8 bytes
-- as all numbers in Lua are doubles.
return msg, 8
elseif t == "boolean" then
-- Booleans are passed by value so need not be touched, and cost 1
-- byte.
return msg, 1
elseif t == "table" then
-- Tables are duplicated. Check if this table has been seen before
-- (self-referential or shared table); if so, reuse the cleaned value
-- of the previous occurrence, maintaining table topology and avoiding
-- infinite recursion, and charge zero bytes for this as the object has
-- already been counted.
back_references = back_references or {}
local bref = back_references[msg]
if bref then
return bref, 0
end
-- Construct a new table by cleaning all the keys and values and adding
-- up their costs, plus 8 bytes as a rough estimate of table overhead.
local cost = 8
local ret = {}
back_references[msg] = ret
for k, v in pairs(msg) do
local k_cost, v_cost
k, k_cost = clean_and_weigh_digiline_message(k, back_references)
v, v_cost = clean_and_weigh_digiline_message(v, back_references)
if k ~= nil and v ~= nil then
-- Only include an element if its key and value are of legal
-- types.
ret[k] = v
end
-- If we only counted the cost of a table element when we actually
-- used it, we would be vulnerable to the following attack:
-- 1. Construct a huge table (too large to pass the cost limit).
-- 2. Insert it somewhere in a table, with a function as a key.
-- 3. Insert it somewhere in another table, with a number as a key.
-- 4. The first occurrence doesnt pay the cost because functions
-- are stripped and therefore the element is dropped.
-- 5. The second occurrence doesnt pay the cost because its in
-- back_references.
-- By counting the costs regardless of whether the objects will be
-- included, we avoid this attack; it may overestimate the cost of
-- some messages, but only those that wont be delivered intact
-- anyway because they contain illegal object types.
cost = cost + k_cost + v_cost
end
return ret, cost
else
return nil, 0
end
return interrupt
end
local function get_digiline_send(pos)
if not digiline then return end
-- itbl: Flat table of functions to run after sandbox cleanup, used to prevent various security hazards
local function get_digiline_send(pos, itbl, send_warning)
if not minetest.global_exists("digilines") then return end
local chan_maxlen = mesecon.setting("luacontroller_digiline_channel_maxlen", 256)
local maxlen = mesecon.setting("luacontroller_digiline_maxlen", 50000)
return function(channel, msg)
-- NOTE: This runs within string metatable sandbox, so don't *rely* on anything of the form (""):y
-- or via anything that could.
-- Make sure channel is string, number or boolean
if (type(channel) ~= "string" and type(channel) ~= "number" and type(channel) ~= "boolean") then
if type(channel) == "string" then
if #channel > chan_maxlen then
send_warning("Channel string too long.")
return false
end
elseif (type(channel) ~= "string" and type(channel) ~= "number" and type(channel) ~= "boolean") then
send_warning("Channel must be string, number or boolean.")
return false
end
-- It is technically possible to send functions over the wire since
-- the high performance impact of stripping those from the data has
-- been decided to not be worth the added realism.
-- Make sure serialized version of the data is not insanely long to
-- prevent DoS-like attacks
local msg_ser = minetest.serialize(msg)
if #msg_ser > mesecon.setting("luacontroller_digiline_maxlen", 50000) then
local msg_cost
msg, msg_cost = clean_and_weigh_digiline_message(msg)
if msg == nil or msg_cost > maxlen then
send_warning("Message was too complex, or contained invalid data.")
return false
end
minetest.after(0, function()
digilines.receptor_send(pos, digiline_rules_luatube, channel, msg)
table.insert(itbl, function ()
-- Runs outside of string metatable sandbox
local luac_id = minetest.get_meta(pos):get_int("luac_id")
mesecon.queue:add_action(pos, "pipeworks:lt_digiline_relay", {channel, luac_id, msg})
end)
return true
end
end
local safe_globals = {
-- Don't add pcall/xpcall unless willing to deal with the consequences (unless very careful, incredibly likely to allow killing server indirectly)
"assert", "error", "ipairs", "next", "pairs", "select",
"tonumber", "tostring", "type", "unpack", "_VERSION"
}
local function create_environment(pos, mem, event)
local function create_environment(pos, mem, event, itbl, send_warning)
-- Make sure the tube hasn't broken.
local vports = minetest.registered_nodes[minetest.get_node(pos).name].virtual_portstates
if not vports then return {} end
@ -352,8 +484,8 @@ local function create_environment(pos, mem, event)
heat = mesecon.get_heat(pos),
heat_max = mesecon.setting("overheat_max", 20),
print = safe_print,
interrupt = get_interrupt(pos),
digiline_send = get_digiline_send(pos),
interrupt = get_interrupt(pos, itbl, send_warning),
digiline_send = get_digiline_send(pos, itbl, send_warning),
string = {
byte = string.byte,
char = string.char,
@ -441,10 +573,11 @@ local function create_sandbox(code, env)
jit.off(f, true)
end
local maxevents = mesecon.setting("luacontroller_maxevents", 10000)
return function(...)
-- NOTE: This runs within string metatable sandbox, so the setting's been moved out for safety
-- Use instruction counter to stop execution
-- after luacontroller_maxevents
local maxevents = mesecon.setting("luacontroller_maxevents", 10000)
debug.sethook(timeout, "", maxevents)
local ok, ret = pcall(f, ...)
debug.sethook() -- Clear hook
@ -455,7 +588,7 @@ end
local function load_memory(meta)
return minetest.deserialize(meta:get_string("lc_memory")) or {}
return minetest.deserialize(meta:get_string("lc_memory"), true) or {}
end
@ -465,6 +598,7 @@ local function save_memory(pos, meta, mem)
if (#memstring <= memsize_max) then
meta:set_string("lc_memory", memstring)
meta:mark_as_private("lc_memory")
else
print("Error: lua_tube memory overflow. "..memsize_max.." bytes available, "
..#memstring.." required. Controller overheats.")
@ -472,26 +606,42 @@ local function save_memory(pos, meta, mem)
end
end
local function run(pos, event)
-- Returns success (boolean), errmsg (string), retval(any, return value of the user supplied code)
-- run (as opposed to run_inner) is responsible for setting up meta according to this output
local function run_inner(pos, code, event)
local meta = minetest.get_meta(pos)
if overheat(pos) then return end
if ignore_event(event, meta) then return end
-- Note: These return success, presumably to avoid changing LC ID.
if overheat(pos) then return true, "", nil end
if ignore_event(event, meta) then return true, "", nil end
-- Load code & mem from meta
local mem = load_memory(meta)
local code = meta:get_string("code")
-- 'Last warning' label.
local warning = ""
local function send_warning(str)
warning = "Warning: " .. str
end
-- Create environment
local env = create_environment(pos, mem, event)
local itbl = {}
local env = create_environment(pos, mem, event, itbl, send_warning)
-- Create the sandbox and execute code
local f, msg = create_sandbox(code, env)
if not f then return false, msg end
local succ, msg = pcall(f)
if not succ then return false, msg end
if not f then return false, msg, nil end
-- Start string true sandboxing
local onetruestring = getmetatable("")
-- If a string sandbox is already up yet inconsistent, something is very wrong
assert(onetruestring.__index == string)
onetruestring.__index = env.string
local success, msg = pcall(f)
onetruestring.__index = string
-- End string true sandboxing
if not success then return false, msg, nil end
if type(env.port) ~= "table" then
return false, "Ports set are invalid."
return false, "Ports set are invalid.", nil
end
-- Actually set the ports
@ -500,35 +650,81 @@ local function run(pos, event)
-- Save memory. This may burn the luacontroller if a memory overflow occurs.
save_memory(pos, meta, env.mem)
return succ, msg
-- Execute deferred tasks
for _, v in ipairs(itbl) do
local failure = v()
if failure then
return false, failure, nil
end
end
return true, warning, msg
end
mesecon.queue:add_function("pipeworks:lc_tube_interrupt", function (pos, luac_id, iid)
-- There is no lua_tube 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_formspec(meta, code, errmsg)
meta:set_string("code", code)
meta:mark_as_private("code")
code = minetest.formspec_escape(code or "")
errmsg = minetest.formspec_escape(tostring(errmsg or ""))
meta:set_string("formspec", "size[12,10]"
.."background[-0.2,-0.25;12.4,10.75;jeija_luac_background.png]"
.."label[0.1,8.3;"..errmsg.."]"
.."textarea[0.2,0.2;12.2,9.5;code;;"..code.."]"
.."image_button[4.75,8.75;2.5,1;jeija_luac_runbutton.png;program;]"
.."image_button_exit[11.72,-0.25;0.425,0.4;jeija_close_window.png;exit;]"
)
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(tostring(errmsg or ""))
meta:set_string("formspec", "size[12,10]"..
"background[-0.2,-0.25;12.4,10.75;jeija_luac_background.png]"..
"textarea[0.2,0.2;12.2,9.5;code;;"..code.."]"..
"image_button[4.75,8.75;2.5,1;jeija_luac_runbutton.png;program;]"..
"image_button_exit[11.72,-0.25;0.425,0.4;jeija_close_window.png;exit;]"..
"label[0.1,9;"..errmsg.."]")
reset_formspec(meta, code, errmsg)
meta:set_int("luac_id", math.random(1, 65535))
end
-- Wraps run_inner with LC-reset-on-error
local function run(pos, event)
local meta = minetest.get_meta(pos)
local code = meta:get_string("code")
local ok, errmsg, retval = run_inner(pos, code, event)
if not ok then
reset_meta(pos, code, errmsg)
else
reset_formspec(meta, code, errmsg)
end
return ok, errmsg, retval
end
local function reset(pos)
set_port_states(pos, {red = false, blue = false, yellow = false,
green = false, black = false, white = false})
end
local function node_timer(pos)
if minetest.registered_nodes[minetest.get_node(pos).name].is_burnt then
return false
end
run(pos, {type="interrupt"})
return false
end
-----------------------
-- A.Queue callbacks --
-----------------------
mesecon.queue:add_function("pipeworks:lc_tube_interrupt", function (pos, luac_id, iid)
-- There is no lua_tube 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)
mesecon.queue:add_function("pipeworks:lt_digiline_relay", function (pos, channel, luac_id, msg)
if not digiline then return end
-- This check is only really necessary because in case of server crash, old actions can be thrown into the future
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
-- The actual work
digiline:receptor_send(pos, digiline_rules_luatube, channel, msg)
end)
-----------------------
-- Node Registration --
@ -558,6 +754,7 @@ local digiline = {
receptor = {},
effector = {
action = function(pos, node, channel, msg)
msg = clean_and_weigh_digiline_message(msg)
run(pos, {type = "digiline", channel = channel, msg = msg})
end
},
@ -565,6 +762,18 @@ local digiline = {
rules = pipeworks.digilines_rules
},
}
local function get_program(pos)
local meta = minetest.get_meta(pos)
return meta:get_string("code")
end
local function set_program(pos, code)
reset(pos)
reset_meta(pos, code)
return run(pos, {type="program"})
end
local function on_receive_fields(pos, form_name, fields, sender)
if not fields.program then
return
@ -574,12 +783,10 @@ local function on_receive_fields(pos, form_name, fields, sender)
minetest.record_protection_violation(pos, name)
return
end
reset(pos)
reset_meta(pos, fields.code)
local succ, err = run(pos, {type="program"})
if not succ then
print(err)
reset_meta(pos, fields.code, err)
local ok, err = set_program(pos, fields.code)
if not ok then
-- it's not an error from the server perspective
minetest.log("action", "Lua controller programming error: " .. tostring(err))
end
end
@ -715,7 +922,11 @@ for white = 0, 1 do
receptor = {
state = mesecon.state.on,
rules = output_rules[cid]
}
},
luacontroller = {
get_program = get_program,
set_program = set_program,
},
}
minetest.register_node(node_name, {
@ -723,6 +934,7 @@ for white = 0, 1 do
drawtype = "nodebox",
tiles = tiles,
paramtype = "light",
is_ground_content = false,
groups = groups,
drop = BASENAME.."000000",
sunlight_propagates = true,
@ -749,6 +961,7 @@ for white = 0, 1 do
pipeworks.after_dig(pos, node)
end,
is_luacontroller = true,
on_timer = node_timer,
tubelike = 1,
tube = {
connect_sides = {front = 1, back = 1, left = 1, right = 1, top = 1, bottom = 1},
@ -762,7 +975,7 @@ for white = 0, 1 do
break
end
end
local succ, msg = run(pos, {
local succ, _, msg = run(pos, {
type = "item",
pin = src,
itemstring = stack:to_string(),
@ -785,14 +998,6 @@ for white = 0, 1 do
minetest.swap_node(pos, {name = "pipeworks:broken_tube_1"})
pipeworks.scan_for_tube_objects(pos)
end,
on_blast = function(pos, intensity)
if not intensity or intensity > 1 + 3^0.5 then
minetest.remove_node(pos)
return {string.format("%s_%s", name, dropname)}
end
minetest.swap_node(pos, {name = "pipeworks:broken_tube_1"})
pipeworks.scan_for_tube_objects(pos)
end,
})
end
end
@ -836,6 +1041,7 @@ minetest.register_node(BASENAME .. "_burnt", {
tiles = tiles_burnt,
is_burnt = true,
paramtype = "light",
is_ground_content = false,
groups = {snappy = 3, tube = 1, tubedevice = 1, not_in_creative_inventory=1},
drop = BASENAME.."000000",
sunlight_propagates = true,