From 737f366741f54659b17bd9c96e2232eedb9735ee Mon Sep 17 00:00:00 2001
From: Thomas Rudin <thomas@rudin.li>
Date: Sat, 29 Dec 2018 21:48:32 +0100
Subject: [PATCH] LuaC: add lightweight interrupts (#449)
---
mesecons_luacontroller/init.lua | 67 ++++++++++++++++++++++-----------
settingtypes.txt | 4 ++
2 files changed, 48 insertions(+), 23 deletions(-)
diff --git a/mesecons_luacontroller/init.lua b/mesecons_luacontroller/init.lua
index 19b6479..1c93e48 100644
--- a/mesecons_luacontroller/init.lua
+++ b/mesecons_luacontroller/init.lua
@@ -266,32 +266,45 @@ local function remove_functions(x)
return x
end
--- itbl: Flat table of functions to run after sandbox cleanup, used to prevent various security hazards
-local function get_interrupt(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 return 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, "lc_interrupt", {luac_id, iid}, time, iid, 1)
- else
- send_warning("An interrupt ID was too large!")
- end
+-- 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
- return interrupt
+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, "lc_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).
@@ -414,7 +427,6 @@ local function get_digiline_send(pos, itbl, send_warning)
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",
@@ -651,6 +663,14 @@ local function reset(pos)
set_port_states(pos, {a=false, b=false, c=false, d=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 --
-----------------------
@@ -823,6 +843,7 @@ for d = 0, 1 do
mesecon.receptor_off(pos, output_rules)
end,
is_luacontroller = true,
+ on_timer = node_timer,
on_blast = mesecon.on_blastnode,
})
end
diff --git a/settingtypes.txt b/settingtypes.txt
index 8be7be6..9259a83 100644
--- a/settingtypes.txt
+++ b/settingtypes.txt
@@ -24,6 +24,10 @@ mesecon.luacontroller_digiline_maxlen (Digiline message size limit) int 50000 10
mesecon.luacontroller_maxevents (Controller execution time limit) int 10000 1000 100000
mesecon.luacontroller_memsize (Controller memory limit) int 100000 10000 1000000
+# Use node timer for interrupts (runs in active blocks only).
+# IID is ignored and at most one interrupt may be queued if this setting is enabled.
+mesecon.luacontroller_lightweight_interrupts (Lightweight interrupts) bool false
+
[mesecons_movestones]
--
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