minetest-mods/MoreMesecons
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Code Issues Releases Wiki Activity

LuaBlock: Major changes in mod storage usage

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Data associated to a LuaBlock is redundantly stored in both its metadata
and in the mod storage so that it is not possible to hack a LuaBlock by
changing its metadata or copying it using WorldEdit. This commit changes
how it is done:
* Store full code instead of storing MD5 checksum, which avoids bug
caused by serializing non-ASCII strings using minetest.serialize,
* Also store owner,
* Use `minetest.hash_node_position` instead of deprecated vector_extras
set_data_to_pos etc,
* Remove mod storage data associated with the LuaBlock when destroying
it,
* Create helper functions for manipulating the mod storage in
moremesecons_utils, I will soon update other parts of MoreMesecons as well to use them.

This commit breaks backwards compatibility: previously created LuaBlocks
will have to be reset by opening the formspec and pressing the `Submit`
button.

This commit also fixes an unrelated bug: code in the formspec was not
correctly escaped using minetest.formspec_escape.
This commit is contained in:
upsilon
2020-04-09 16:13:51 +02:00
parent 2b2faeca02
commit 7cf99da1a5
12 changed files with 50 additions and 652 deletions
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44
moremesecons_luablock/init.lua
View File

@ -1,20 +1,21 @@
local md5 = dofile(minetest.get_modpath(minetest.get_current_modname()).."/md5_lua/md5.lua")
local storage = minetest.get_mod_storage()
local hash_table = minetest.deserialize(storage:get_string("hash_table")) or {}
local pos_data = moremesecons.get_storage_data(storage, "pos_data")
local function set_md5(pos, code)
vector.set_data_to_pos(hash_table, pos.z,pos.y,pos.x, md5.sum(code))
storage:set_string("hash_table", minetest.serialize(hash_table))
local function set_data(pos, code, owner)
local data = {
code = code,
owner = owner
}
moremesecons.set_data_to_pos(pos_data, pos, data)
end
local function check_md5(pos, code)
local stored_sum = vector.get_data_from_pos(hash_table, pos.z,pos.y,pos.x)
if not stored_sum then
-- Legacy
set_md5(pos, code)
return true
local function check_data(pos, code, owner)
local stored_data = moremesecons.get_data_from_pos(pos_data, pos)
if not stored_data then
return false
end
if md5.sum(code) ~= stored_sum then
if code ~= stored_data.code
or owner ~= stored_data.owner then
return false
end
return true
@ -22,11 +23,11 @@ end
local function make_formspec(meta, pos)
local code = meta:get_string("code")
local code = minetest.formspec_escape(meta:get_string("code"))
local errmsg = minetest.formspec_escape(meta:get_string("errmsg"))
meta:set_string("formspec",
"size[10,8;]" ..
"textarea[0.5,0.5;10,7;code;Code;"..code.."]" ..
"textarea[0.5,0.5;9.5,7;code;Code;"..code.."]" ..
"label[0.1,7;"..errmsg.."]" ..
"button_exit[4,7.5;2,1;submit;Submit]")
end
@ -97,22 +98,26 @@ minetest.register_node("moremesecons_luablock:luablock", {
end
meta:set_string("code", fields.code)
set_md5(pos, fields.code)
set_data(pos, fields.code, name)
make_formspec(meta, pos)
end,
can_dig = function(pos, player)
local meta = minetest.get_meta(pos)
return meta:get_string("owner") == player:get_player_name()
end,
on_destruct = function(pos)
moremesecons.remove_data_from_pos(pos_data, pos)
end,
mesecons = {effector = {
action_on = function(npos, node)
local meta = minetest.get_meta(npos)
local code = meta:get_string("code")
local owner = meta:get_string("owner")
if code == "" then
return
end
if not check_md5(npos, code) then
minetest.log("warning", "[moremesecons_luablock] Code of LuaBlock at pos "..minetest.pos_to_string(npos).." does not match with its md5 checksum!")
if not check_data(npos, code, owner) then
minetest.log("warning", "[moremesecons_luablock] Metadata of LuaBlock at pos "..minetest.pos_to_string(npos).." does not match its mod storage data!")
return
end
-- We do absolutely no check there.
@ -127,7 +132,10 @@ minetest.register_node("moremesecons_luablock:luablock", {
return
end
-- Set the "pos" global
local old_pos = pos -- In case there's already an existing "pos" global
local old_pos
if minetest.global_exists("pos") then
old_pos = pos -- In case there's already an existing "pos" global
end
pos = table.copy(npos)
local good, err = pcall(func)
pos = old_pos