1 files changed, 167 insertions, 0 deletions
diff --git a/script/sandbox.lua b/script/sandbox.lua
new file mode 100644
index 00000000..6b2f2a32
--- /dev/null
+++ b/script/sandbox.lua
@@ -0,0 +1,167 @@
+local function standard(loaded, env)
+    local r = env or {}
+    for _, s in ipairs {
+        --'package',
+        'coroutine',
+        'table',
+        --'io',
+        'os',
+        'string',
+        'math',
+        'utf8',
+        'debug',
+    } do
+        r[s] = _G[s]
+        loaded[s] = _G[s]
+    end
+    for _, s in ipairs {
+        'assert',
+        'collectgarbage',
+        --'dofile',
+        'error',
+        'getmetatable',
+        'ipairs',
+        --'loadfile',
+        'load',
+        'next',
+        'pairs',
+        'pcall',
+        'print',
+        'rawequal',
+        'rawlen',
+        'rawget',
+        'rawset',
+        'select',
+        'setmetatable',
+        'tonumber',
+        'tostring',
+        'type',
+        'xpcall',
+        '_VERSION',
+        --'require',
+    } do
+        r[s] = _G[s]
+    end
+    return r
+end
+
+local function sandbox_env(loadlua, openfile, loaded, env)
+    local _LOADED = loaded or {}
+    local _E = standard(_LOADED, env)
+    local _PRELOAD = {}
+
+    _E.io = {
+        open = openfile,
+    }
+
+    local function searchpath(name, path)
+        local err = ''
+        name = string.gsub(name, '%.', '/')
+        for c in string.gmatch(path, '[^;]+') do
+            local filename = string.gsub(c, '%?', name)
+            local f = openfile(filename)
+            if f then
+                f:close()
+                return filename
+            end
+            err = err .. ("\n\tno file '%s'"):format(filename)
+        end
+        return nil, err
+    end
+
+    local function searcher_preload(name)
+        assert(type(_PRELOAD) == "table", "'package.preload' must be a table")
+        if _PRELOAD[name] == nil then
+            return ("\n\tno field package.preload['%s']"):format(name)
+        end
+        return _PRELOAD[name]
+    end
+
+    local function searcher_lua(name)
+        assert(type(_E.package.path) == "string", "'package.path' must be a string")
+        local filename, err = searchpath(name, _E.package.path)
+        if not filename then
+            return err
+        end
+        local f, err = loadlua(filename)
+        if not f then
+            error(("error loading module '%s' from file '%s':\n\t%s"):format(name, filename, err))
+        end
+        return f, filename
+    end
+
+    local function require_load(name)
+        local msg = ''
+        local _SEARCHERS = _E.package.searchers
+        assert(type(_SEARCHERS) == "table", "'package.searchers' must be a table")
+        for _, searcher in ipairs(_SEARCHERS) do
+            local f, extra = searcher(name)
+            if type(f) == 'function' then
+                return f, extra
+            elseif type(f) == 'string' then
+                msg = msg .. f
+            end
+        end
+        error(("module '%s' not found:%s"):format(name, msg))
+    end
+
+    _E.require = function(name)
+        assert(type(name) == "string", ("bad argument #1 to 'require' (string expected, got %s)"):format(type(name)))
+        local p = _LOADED[name]
+        if p ~= nil then
+            return p
+        end
+        local init, extra = require_load(name)
+        if debug.getupvalue(init, 1) == '_ENV' then
+            debug.setupvalue(init, 1, _E)
+        end
+        local res = init(name, extra)
+        if res ~= nil then
+            _LOADED[name] = res
+        end
+        if _LOADED[name] == nil then
+            _LOADED[name] = true
+        end
+        return _LOADED[name]
+    end
+    _E.package = {
+        config = [[
+            \
+            ;
+            ?
+            !
+            -
+        ]],
+        loaded = _LOADED,
+        path = '?.lua',
+        preload = _PRELOAD,
+        searchers = { searcher_preload, searcher_lua },
+        searchpath = searchpath
+    }
+    return _E
+end
+
+return function(name, root, io_open, loaded, env)
+    if not root:sub(-1):find '[/\\]' then
+        root = root .. '/'
+    end
+    local function openfile(name, mode)
+        return io_open(root .. name, mode)
+    end
+    local function loadlua(name)
+        local f = openfile(name, 'r')
+        if f then
+            local str = f:read 'a'
+            f:close()
+            return load(str, '@' .. root .. name)
+        end
+    end
+    local init = loadlua(name)
+    if not init then
+        return
+    end
+    if debug.getupvalue(init, 1) == '_ENV' then
+        debug.setupvalue(init, 1, sandbox_env(loadlua, openfile, loaded, env))
+    end
+    return init()
+end