Create a filesystem abstraction layer for CSM and only allow accessin…

…g files that are scanned into it. (#5965) * Load client-side mods into memory before executing them. This removes the remaining filesystem access that client-sided mods had and it will hopefully make then more secure. * Lua Virtual filesystem: don't load the files into memory just scan the filenames into memory. * Fix the issues with backtrace * fix most of the issues * fix code style. * add a comment
minetest · Jun 30, 2017 · f3ad756 · f3ad756
1 parent 2e53801
commit f3ad756
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Showing 24 changed files with 230 additions and 101 deletions.
diff --git a/builtin/client/init.lua b/builtin/client/init.lua
@@ -1,5 +1,5 @@
 -- Minetest: builtin/client/init.lua
-local scriptpath = core.get_builtin_path()..DIR_DELIM
+local scriptpath = core.get_builtin_path()
 local clientpath = scriptpath.."client"..DIR_DELIM
 local commonpath = scriptpath.."common"..DIR_DELIM
 

diff --git a/builtin/game/init.lua b/builtin/game/init.lua
@@ -1,5 +1,5 @@
 
-local scriptpath = core.get_builtin_path()..DIR_DELIM
+local scriptpath = core.get_builtin_path()
 local commonpath = scriptpath.."common"..DIR_DELIM
 local gamepath = scriptpath.."game"..DIR_DELIM
 

diff --git a/builtin/init.lua b/builtin/init.lua
@@ -25,7 +25,7 @@ os.setlocale("C", "numeric")
 minetest = core
 
 -- Load other files
-local scriptdir = core.get_builtin_path() .. DIR_DELIM
+local scriptdir = core.get_builtin_path()
 local gamepath = scriptdir .. "game" .. DIR_DELIM
 local clientpath = scriptdir .. "client" .. DIR_DELIM
 local commonpath = scriptdir .. "common" .. DIR_DELIM

diff --git a/builtin/mainmenu/dlg_settings_advanced.lua b/builtin/mainmenu/dlg_settings_advanced.lua
@@ -264,7 +264,7 @@ end
 -- read_all: whether to ignore certain setting types for GUI or not
 -- parse_mods: whether to parse settingtypes.txt in mods and games
 local function parse_config_file(read_all, parse_mods)
-	local builtin_path = core.get_builtin_path() .. DIR_DELIM .. FILENAME
+	local builtin_path = core.get_builtin_path() .. FILENAME
 	local file = io.open(builtin_path, "r")
 	local settings = {}
 	if not file then
@@ -775,4 +775,4 @@ end
 
 -- Generate minetest.conf.example and settings_translation_file.cpp
 
---assert(loadfile(core.get_builtin_path()..DIR_DELIM.."mainmenu"..DIR_DELIM.."generate_from_settingtypes.lua"))(parse_config_file(true, false))
+--assert(loadfile(core.get_builtin_path().."mainmenu"..DIR_DELIM.."generate_from_settingtypes.lua"))(parse_config_file(true, false))
diff --git a/builtin/mainmenu/init.lua b/builtin/mainmenu/init.lua
@@ -27,12 +27,12 @@ local basepath = core.get_builtin_path()
 defaulttexturedir = core.get_texturepath_share() .. DIR_DELIM .. "base" ..
 					DIR_DELIM .. "pack" .. DIR_DELIM
 
-dofile(basepath .. DIR_DELIM .. "common" .. DIR_DELIM .. "async_event.lua")
-dofile(basepath .. DIR_DELIM .. "common" .. DIR_DELIM .. "filterlist.lua")
-dofile(basepath .. DIR_DELIM .. "fstk" .. DIR_DELIM .. "buttonbar.lua")
-dofile(basepath .. DIR_DELIM .. "fstk" .. DIR_DELIM .. "dialog.lua")
-dofile(basepath .. DIR_DELIM .. "fstk" .. DIR_DELIM .. "tabview.lua")
-dofile(basepath .. DIR_DELIM .. "fstk" .. DIR_DELIM .. "ui.lua")
+dofile(basepath .. "common" .. DIR_DELIM .. "async_event.lua")
+dofile(basepath .. "common" .. DIR_DELIM .. "filterlist.lua")
+dofile(basepath .. "fstk" .. DIR_DELIM .. "buttonbar.lua")
+dofile(basepath .. "fstk" .. DIR_DELIM .. "dialog.lua")
+dofile(basepath .. "fstk" .. DIR_DELIM .. "tabview.lua")
+dofile(basepath .. "fstk" .. DIR_DELIM .. "ui.lua")
 dofile(menupath .. DIR_DELIM .. "common.lua")
 dofile(menupath .. DIR_DELIM .. "gamemgr.lua")
 dofile(menupath .. DIR_DELIM .. "modmgr.lua")

diff --git a/builtin/profiler/init.lua b/builtin/profiler/init.lua
@@ -23,7 +23,7 @@ local function get_bool_default(name, default)
 	return val
 end
 
-local profiler_path = core.get_builtin_path()..DIR_DELIM.."profiler"..DIR_DELIM
+local profiler_path = core.get_builtin_path().."profiler"..DIR_DELIM
 local profiler = {}
 local sampler = assert(loadfile(profiler_path .. "sampling.lua"))(profiler)
 local instrumentation  = assert(loadfile(profiler_path .. "instrumentation.lua"))(profiler, sampler, get_bool_default)

diff --git a/clientmods/preview/example.lua b/clientmods/preview/example.lua
@@ -0,0 +1,2 @@
+print("Loaded example file!, loading more examples")
+dofile("preview:examples/first.lua")
diff --git a/clientmods/preview/examples/first.lua b/clientmods/preview/examples/first.lua
@@ -0,0 +1 @@
+print("loaded first.lua example file")
diff --git a/clientmods/preview/init.lua b/clientmods/preview/init.lua
@@ -1,6 +1,7 @@
 local modname = core.get_current_modname() or "??"
 local modstorage = core.get_mod_storage()
 
+dofile("preview:example.lua")
 -- This is an example function to ensure it's working properly, should be removed before merge
 core.register_on_shutdown(function()
 	print("[PREVIEW] shutdown client")

diff --git a/src/client.cpp b/src/client.cpp
@@ -104,17 +104,17 @@ Client::Client(
 	m_script->setEnv(&m_env);
 }
 
-void Client::initMods()
+void Client::loadMods()
 {
-	m_script->loadMod(getBuiltinLuaPath() + DIR_DELIM "init.lua", BUILTIN_MOD_NAME);
+	// Load builtin
+	scanModIntoMemory(BUILTIN_MOD_NAME, getBuiltinLuaPath());
 
 	// If modding is not enabled, don't load mods, just builtin
 	if (!m_modding_enabled) {
 		return;
 	}
-
 	ClientModConfiguration modconf(getClientModsLuaPath());
-	std::vector<ModSpec> mods = modconf.getMods();
+	m_mods = modconf.getMods();
 	std::vector<ModSpec> unsatisfied_mods = modconf.getUnsatisfiedMods();
 	// complain about mods with unsatisfied dependencies
 	if (!modconf.isConsistent()) {
@@ -123,28 +123,52 @@ void Client::initMods()
 
 	// Print mods
 	infostream << "Client Loading mods: ";
-	for (std::vector<ModSpec>::const_iterator i = mods.begin();
-		i != mods.end(); ++i) {
-		infostream << (*i).name << " ";
-	}
-
+	for (const ModSpec &mod : m_mods)
+		infostream << mod.name << " ";
 	infostream << std::endl;
+
 	// Load and run "mod" scripts
-	for (std::vector<ModSpec>::const_iterator it = mods.begin();
-		it != mods.end(); ++it) {
-		const ModSpec &mod = *it;
+	for (const ModSpec &mod : m_mods) {
 		if (!string_allowed(mod.name, MODNAME_ALLOWED_CHARS)) {
 			throw ModError("Error loading mod \"" + mod.name +
 				"\": Mod name does not follow naming conventions: "
 					"Only characters [a-z0-9_] are allowed.");
 		}
-		std::string script_path = mod.path + DIR_DELIM + "init.lua";
-		infostream << "  [" << padStringRight(mod.name, 12) << "] [\""
-			<< script_path << "\"]" << std::endl;
-		m_script->loadMod(script_path, mod.name);
+		scanModIntoMemory(mod.name, mod.path);
+	}
+}
+
+void Client::scanModSubfolder(const std::string &mod_name, const std::string &mod_path,
+			std::string mod_subpath)
+{
+	std::string full_path = mod_path + DIR_DELIM + mod_subpath;
+	std::vector<fs::DirListNode> mod = fs::GetDirListing(full_path);
+	for (unsigned int j=0; j < mod.size(); j++){
+		std::string filename = mod[j].name;
+		if (mod[j].dir) {
+			scanModSubfolder(mod_name, mod_path, mod_subpath
+					+ filename + DIR_DELIM);
+			continue;
+		}
+		std::replace( mod_subpath.begin(), mod_subpath.end(), DIR_DELIM_CHAR, '/');
+		m_mod_files[mod_name + ":" + mod_subpath + filename] = full_path  + filename;
 	}
 }
 
+void Client::initMods()
+{
+	m_script->loadModFromMemory(BUILTIN_MOD_NAME);
+
+	// If modding is not enabled, don't load mods, just builtin
+	if (!m_modding_enabled) {
+		return;
+	}
+
+	// Load and run "mod" scripts
+	for (const ModSpec &mod : m_mods)
+		m_script->loadModFromMemory(mod.name);
+}
+
 const std::string &Client::getBuiltinLuaPath()
 {
 	static const std::string builtin_dir = porting::path_share + DIR_DELIM + "builtin";
@@ -1898,6 +1922,17 @@ scene::IAnimatedMesh* Client::getMesh(const std::string &filename)
 	return mesh;
 }
 
+const std::string* Client::getModFile(const std::string &filename)
+{
+	StringMap::const_iterator it = m_mod_files.find(filename);
+	if (it == m_mod_files.end()) {
+		errorstream << "Client::getModFile(): File not found: \"" << filename
+			<< "\"" << std::endl;
+		return NULL;
+	}
+	return &it->second;
+}
+
 bool Client::registerModStorage(ModMetadata *storage)
 {
 	if (m_mod_storages.find(storage->getModName()) != m_mod_storages.end()) {

diff --git a/src/client.h b/src/client.h
@@ -37,6 +37,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "mapnode.h"
 #include "tileanimation.h"
 #include "mesh_generator_thread.h"
+#include <fstream>
+#include "filesys.h"
 
 #define CLIENT_CHAT_MESSAGE_LIMIT_PER_10S 10.0f
 
@@ -273,6 +275,16 @@ class Client : public con::PeerHandler, public InventoryManager, public IGameDef
 	~Client();
 	DISABLE_CLASS_COPY(Client);
 
+	// Load local mods into memory
+	void loadMods();
+	void scanModSubfolder(const std::string &mod_name, const std::string &mod_path,
+				std::string mod_subpath);
+	inline void scanModIntoMemory(const std::string &mod_name, const std::string &mod_path)
+	{
+		scanModSubfolder(mod_name, mod_path, "");
+	}
+
+	// Initizle the mods
 	void initMods();
 
 	/*
@@ -492,6 +504,7 @@ class Client : public con::PeerHandler, public InventoryManager, public IGameDef
 	bool checkLocalPrivilege(const std::string &priv)
 	{ return checkPrivilege(priv); }
 	virtual scene::IAnimatedMesh* getMesh(const std::string &filename);
+	const std::string* getModFile(const std::string &filename);
 
 	virtual std::string getModStoragePath() const;
 	virtual bool registerModStorage(ModMetadata *meta);
@@ -672,6 +685,8 @@ class Client : public con::PeerHandler, public InventoryManager, public IGameDef
 	// Storage for mesh data for creating multiple instances of the same mesh
 	StringMap m_mesh_data;
 
+	StringMap m_mod_files;
+
 	// own state
 	LocalClientState m_state;
 
@@ -684,6 +699,7 @@ class Client : public con::PeerHandler, public InventoryManager, public IGameDef
 	bool m_modding_enabled;
 	std::unordered_map<std::string, ModMetadata *> m_mod_storages;
 	float m_mod_storage_save_timer = 10.0f;
+	std::vector<ModSpec> m_mods;
 	GameUIFlags *m_game_ui_flags;
 
 	bool m_shutdown = false;

diff --git a/src/game.cpp b/src/game.cpp
@@ -2121,6 +2121,7 @@ bool Game::connectToServer(const std::string &playername,
 
 		fps_control.last_time = RenderingEngine::get_timer_time();
 
+		client->loadMods();
 		client->initMods();
 
 		while (RenderingEngine::run()) {

diff --git a/src/script/common/c_internal.cpp b/src/script/common/c_internal.cpp
@@ -24,37 +24,9 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 std::string script_get_backtrace(lua_State *L)
 {
-	std::string s;
-	lua_getglobal(L, "debug");
-	if(lua_istable(L, -1)){
-		lua_getfield(L, -1, "traceback");
-		if(lua_isfunction(L, -1)) {
-			lua_call(L, 0, 1);
-			if(lua_isstring(L, -1)){
-				s = lua_tostring(L, -1);
-			}
-		}
-		lua_pop(L, 1);
-	}
-	lua_pop(L, 1);
-	return s;
-}
-
-int script_error_handler(lua_State *L) {
-	lua_getglobal(L, "debug");
-	if (!lua_istable(L, -1)) {
-		lua_pop(L, 1);
-		return 1;
-	}
-	lua_getfield(L, -1, "traceback");
-	if (!lua_isfunction(L, -1)) {
-		lua_pop(L, 2);
-		return 1;
-	}
-	lua_pushvalue(L, 1);
-	lua_pushinteger(L, 2);
-	lua_call(L, 2, 1);
-	return 1;
+	lua_rawgeti(L, LUA_REGISTRYINDEX, CUSTOM_RIDX_BACKTRACE);
+	lua_call(L, 0, 1);
+	return luaL_checkstring(L, -1);
 }
 
 int script_exception_wrapper(lua_State *L, lua_CFunction f)

diff --git a/src/script/common/c_internal.h b/src/script/common/c_internal.h
@@ -53,11 +53,11 @@ extern "C" {
 #define CUSTOM_RIDX_SCRIPTAPI           (CUSTOM_RIDX_BASE)
 #define CUSTOM_RIDX_GLOBALS_BACKUP      (CUSTOM_RIDX_BASE + 1)
 #define CUSTOM_RIDX_CURRENT_MOD_NAME    (CUSTOM_RIDX_BASE + 2)
-#define CUSTOM_RIDX_ERROR_HANDLER       (CUSTOM_RIDX_BASE + 3)
+#define CUSTOM_RIDX_BACKTRACE           (CUSTOM_RIDX_BASE + 3)
 
 // Pushes the error handler onto the stack and returns its index
 #define PUSH_ERROR_HANDLER(L) \
-	(lua_rawgeti((L), LUA_REGISTRYINDEX, CUSTOM_RIDX_ERROR_HANDLER), lua_gettop((L)))
+	(lua_rawgeti((L), LUA_REGISTRYINDEX, CUSTOM_RIDX_BACKTRACE), lua_gettop((L)))
 
 #define PCALL_RESL(L, RES) do {                         \
 	int result_ = (RES);                                \

diff --git a/src/script/cpp_api/s_base.cpp b/src/script/cpp_api/s_base.cpp
@@ -89,8 +89,10 @@ ScriptApiBase::ScriptApiBase()
 	lua_rawseti(m_luastack, LUA_REGISTRYINDEX, CUSTOM_RIDX_SCRIPTAPI);
 
 	// Add and save an error handler
-	lua_pushcfunction(m_luastack, script_error_handler);
-	lua_rawseti(m_luastack, LUA_REGISTRYINDEX, CUSTOM_RIDX_ERROR_HANDLER);
+	lua_getglobal(m_luastack, "debug");
+	lua_getfield(m_luastack, -1, "traceback");
+	lua_rawseti(m_luastack, LUA_REGISTRYINDEX, CUSTOM_RIDX_BACKTRACE);
+	lua_pop(m_luastack, 1); // pop debug
 
 	// If we are using LuaJIT add a C++ wrapper function to catch
 	// exceptions thrown in Lua -> C++ calls
@@ -158,6 +160,35 @@ void ScriptApiBase::loadScript(const std::string &script_path)
 	lua_pop(L, 1); // Pop error handler
 }
 
+#ifndef SERVER
+void ScriptApiBase::loadModFromMemory(const std::string &mod_name)
+{
+	ModNameStorer mod_name_storer(getStack(), mod_name);
+
+	const std::string *init_filename = getClient()->getModFile(mod_name + ":init.lua");
+	const std::string display_filename = mod_name + ":init.lua";
+	if(init_filename == NULL)
+		throw ModError("Mod:\"" + mod_name + "\" lacks init.lua");
+
+	verbosestream << "Loading and running script " << display_filename << std::endl;
+
+	lua_State *L = getStack();
+
+	int error_handler = PUSH_ERROR_HANDLER(L);
+
+	bool ok = ScriptApiSecurity::safeLoadFile(L, init_filename->c_str(), display_filename.c_str());
+	if (ok)
+		ok = !lua_pcall(L, 0, 0, error_handler);
+	if (!ok) {
+		std::string error_msg = luaL_checkstring(L, -1);
+		lua_pop(L, 2); // Pop error message and error handler
+		throw ModError("Failed to load and run mod \"" +
+				mod_name + "\":\n" + error_msg);
+	}
+	lua_pop(L, 1); // Pop error handler
+}
+#endif
+
 // Push the list of callbacks (a lua table).
 // Then push nargs arguments.
 // Then call this function, which

diff --git a/src/script/cpp_api/s_base.h b/src/script/cpp_api/s_base.h
@@ -54,6 +54,12 @@ extern "C" {
 #define setOriginFromTable(index) \
 	setOriginFromTableRaw(index, __FUNCTION__)
 
+enum class ScriptingType: u8 {
+	Client,
+	Server,
+	MainMenu
+};
+
 class Server;
 #ifndef SERVER
 class Client;
@@ -73,6 +79,10 @@ class ScriptApiBase {
 	void loadMod(const std::string &script_path, const std::string &mod_name);
 	void loadScript(const std::string &script_path);
 
+#ifndef SERVER
+	void loadModFromMemory(const std::string &mod_name);
+#endif
+
 	void runCallbacksRaw(int nargs,
 		RunCallbacksMode mode, const char *fxn);
 
@@ -82,6 +92,8 @@ class ScriptApiBase {
 
 	IGameDef *getGameDef() { return m_gamedef; }
 	Server* getServer();
+	void setType(ScriptingType type) { m_type = type; }
+	ScriptingType getType() { return m_type; }
 #ifndef SERVER
 	Client* getClient();
 #endif
@@ -133,6 +145,7 @@ class ScriptApiBase {
 	IGameDef       *m_gamedef = nullptr;
 	Environment    *m_environment = nullptr;
 	GUIEngine      *m_guiengine = nullptr;
+	ScriptingType  m_type;
 };
 
 #endif /* S_BASE_H_ */