Testcode for unsafe functions

test_unsafe_functions.lua

local os_functiontable =  {
	-- fct,     allowed,   p1, p2, p3
	{ "clock",       true, nil, nil, nil },
	{ "date",        true, nil, nil, nil },
	{ "difftime",    true, 10000, 9000, nil },
	{ "execute",    false, "/bin/true", nil, nil },
	{ "getenv",     false, "SHELL", nil, nil },
	{ "rename",     false, "/tmp/somefile", "/tmp/someotherfile", nil },
	{ "remove",     false, "/tmp/someotherfile", nil, nil },
	{ "setlocale",  false, "de_DE.utf8", "all", nil },
	{ "time",        true, nil, nil, nil },
	{ "tmpname",    false, nil, nil, nil },
	{ "exit",       false, 0, nil, nil }
}


local check_function_table = function(fcttable, pkgname, pkg)

	for i=1, #fcttable, 1 do
		minetest.log("action", "Testing for " .. pkgname .. "." .. fcttable[i][1] .. "...")
		if type(pkg[fcttable[i][1]]) == "function" then
		
			minetest.log("action", "\tfunction present")
			local call_successfull = false
			local message = "\tfunction "
		
			local fctretval = pkg[fcttable[i][1]](fcttable[i][3], fcttable[i][4], fcttable[i][5])
		
			if fctretval then
				call_successfull = true
				message = message .. "works "
			else
				message = message .. "does not work "
			end
			
			if call_successfull ~= fcttable[i][2] then
				message = message .. "==> BAD!"
			end
		
			minetest.log("error", message)
			minetest.log("error", "\tfunction returned: " .. dump(fctretval))
		end
	end
end


local check_function = function(fct, name, shallwork, p1, p2, p3)
	minetest.log("action", "Testing for " .. name .. "...")
	if type(fct) == "function" then
		minetest.log("action", "\tfunction present")
		local call_successfull = false
		local message = "\tfunction "
		
		local fctretval = fct(p1,p2,p3)
		
		if fctretval then
			call_successfull = true
			message = message .. "works "
		else
			message = message .. "does not work "
		end
			
		if call_successfull ~= shallwork then
			message = message .. "==> BAD!"
		end
		
		minetest.log("error", message)
		minetest.log("error", "\tfunction returned: " .. dump(fctretval))
	end
end

local package_functiontable =  {
	-- fct,        allowed,   p1, p2, p3
	{ "config",      false, nil, nil, nil },
	{ "cpath",       false, nil, nil, nil },
	{ "loaded",      false, nil, nil, nil },
	{ "loadlib",     false, nil, nil, nil },
	{ "path",        false, nil, nil, nil },
	{ "preload",     false, nil, nil, nil },
	{ "searchers",   false, nil, nil, nil },
	{ "searchpath",  false, nil, nil, nil },
}

local sethooktest = function()
	if called_once == nil then
		print("Sethooktest is now called everytime a function is called!")
		called_once = 1
	end
end

local debug_functiontable =  {
	-- fct,     allowed,   p1, p2, p3
	{      "gethook",     false, nil, nil, nil },
	{      "getinfo",     false,   1, nil, nil },
	{     "getlocal",     false,   1,   1, nil },
	{ "getmetatable",     false,  os, nil, nil },
	{  "getregistry",     false, nil, nil, nil },
	{   "getupvalue",     false, nil, nil, nil },
	{ "getuservalue",     false, nil, nil, nil },
	{      "sethook",     false, sethooktest, "c", nil },
	{ "setmetatable",     false, nil, nil, nil },
	{ "setuservalue",     false, nil, nil, nil },
	{    "traceback",     false, nil, nil, nil },
	{    "upvalueid",     false, nil, nil, nil },
	{  "upvaluejoin",     false, nil, nil, nil },
-- will stop application so user will find out
--	{        "debug",     false, nil, nil, nil },
}

local loadfcttest = function()

end

-- check builtins
-- bad makes test hang
check_function(dofile,             "dofile", false, "/tmp/somefile")
check_function(getmetatable, "getmetatable", false, _G)
check_function(load,                 "load", false, loadfcttest, "local dummy=1")
check_function(loadfile,         "loadfile", false, "/tmp/somefile")
--prevented by modsecurity atm but in a way breaking test
--check_function(require,           "require", false, "/tmp/somefile")

-- check standard libs
check_function_table(debug_functiontable, "debug", debug)
check_function_table(package_functiontable, "package", package)
check_function_table(os_functiontable, "os", os)