diff options
Diffstat (limited to 'liblogdiag')
| -rw-r--r-- | liblogdiag/ld-lua.c | 185 |
1 files changed, 98 insertions, 87 deletions
diff --git a/liblogdiag/ld-lua.c b/liblogdiag/ld-lua.c index d16f327..18bf9ce 100644 --- a/liblogdiag/ld-lua.c +++ b/liblogdiag/ld-lua.c @@ -2,7 +2,7 @@ * ld-lua.c * * This file is a part of logdiag. - * Copyright Přemysl Janouch 2010 - 2011. All rights reserved. + * Copyright Přemysl Janouch 2010, 2011, 2012. All rights reserved. * * See the file LICENSE for licensing information. * @@ -44,9 +44,10 @@ struct _LdLuaPrivate * -> The rendering function */ -#define LD_LUA_LIBRARY_NAME "logdiag" -#define LD_LUA_DATA_INDEX LD_LUA_LIBRARY_NAME "_data" -#define LD_LUA_SYMBOLS_INDEX LD_LUA_LIBRARY_NAME "_symbols" +#define LD_LUA_LIBRARY_NAME "logdiag" +#define LD_LUA_DATA_INDEX LD_LUA_LIBRARY_NAME "_data" +#define LD_LUA_SYMBOLS_INDEX LD_LUA_LIBRARY_NAME "_symbols" +#define LD_LUA_META_INDEX LD_LUA_LIBRARY_NAME "_meta" /* * LdLuaData: @@ -88,7 +89,6 @@ static gboolean read_symbol_area (lua_State *L, int index, LdRectangle *area); static gboolean read_terminals (lua_State *L, int index, LdPointArray **terminals); -static void push_cairo_object (lua_State *L, LdLuaDrawData *draw_data); static gdouble get_cairo_scale (cairo_t *cr); static int ld_lua_cairo_save (lua_State *L); static int ld_lua_cairo_restore (lua_State *L); @@ -164,6 +164,24 @@ ld_lua_class_init (LdLuaClass *klass) } static void +push_cairo_metatable (lua_State *L) +{ + luaL_Reg *fn; + + luaL_newmetatable (L, LD_LUA_META_INDEX); + + /* Create a method table. */ + lua_newtable (L); + for (fn = ld_lua_cairo_table; fn->name; fn++) + { + lua_pushcfunction (L, fn->func); + lua_setfield (L, -2, fn->name); + } + + lua_setfield (L, -2, "__index"); +} + +static void ld_lua_init (LdLua *self) { lua_State *L; @@ -175,7 +193,7 @@ ld_lua_init (LdLua *self) L = self->priv->L = lua_newstate (ld_lua_alloc, NULL); g_return_if_fail (L != NULL); - /* TODO: lua_atpanic () */ + /* XXX: Might not be a bad idea to use lua_atpanic(). */ /* Load some safe libraries. */ lua_pushcfunction (L, luaopen_string); @@ -191,7 +209,7 @@ ld_lua_init (LdLua *self) luaL_register (L, LD_LUA_LIBRARY_NAME, ld_lua_logdiag_lib); /* Store user data to the registry. */ - ud = lua_newuserdata (L, sizeof (LdLuaData)); + ud = lua_newuserdata (L, sizeof *ud); ud->self = self; ud->load_callback = NULL; ud->load_user_data = NULL; @@ -201,6 +219,8 @@ ld_lua_init (LdLua *self) /* Create an empty symbol table. */ lua_newtable (L); lua_setfield (L, LUA_REGISTRYINDEX, LD_LUA_SYMBOLS_INDEX); + + push_cairo_metatable (L); } static void @@ -278,7 +298,7 @@ ld_lua_load_file (LdLua *self, const gchar *filename, g_return_val_if_fail (filename != NULL, FALSE); g_return_val_if_fail (callback != NULL, FALSE); - /* XXX: If something from the following fails, Lua will call exit(). */ + /* XXX: If something from the following fails, Lua will panic. */ lua_getfield (self->priv->L, LUA_REGISTRYINDEX, LD_LUA_DATA_INDEX); ud = lua_touserdata (self->priv->L, -1); lua_pop (self->priv->L, 1); @@ -344,7 +364,7 @@ ld_lua_private_draw (LdLua *self, LdLuaSymbol *symbol, cairo_t *cr) static int ld_lua_private_draw_cb (lua_State *L) { - LdLuaDrawData *data; + LdLuaDrawData *data, *luadata; data = lua_touserdata (L, -1); @@ -357,9 +377,28 @@ ld_lua_private_draw_cb (lua_State *L) lua_getfield (L, -1, "render"); luaL_checktype (L, -1, LUA_TFUNCTION); - /* Call the function do draw the symbol. */ - push_cairo_object (L, data); - lua_pcall (L, 1, 0, 0); + /* Create a Cairo wrapper object. */ + luadata = lua_newuserdata (L, sizeof *data); + memcpy (luadata, data, sizeof *data); + lua_getfield (L, LUA_REGISTRYINDEX, LD_LUA_META_INDEX); + lua_setmetatable (L, -2); + + /* Force it to stay alive for a bit longer. */ + lua_pushvalue (L, -1); + lua_insert (L, 1); + + /* Draw the symbol. */ + if (lua_pcall (L, 1, 0, 0)) + { + g_warning ("Lua error: %s", lua_tostring (L, -1)); + lua_pop (L, 1); + } + + /* Copy the userdata back and invalidate it, so that malicious Lua + * scripts won't succeed at drawing onto a long invalid Cairo context. + */ + memcpy (data, luadata, sizeof *data); + memset (luadata, 0, sizeof *data); return 0; } @@ -562,7 +601,7 @@ read_symbol_area (lua_State *L, int index, LdRectangle *area) area->x = MIN (x1, x2); area->y = MIN (y1, y2); - area->width = ABS (x2 - x1); + area->width = ABS (x2 - x1); area->height = ABS (y2 - y1); lua_pop (L, 4); @@ -622,32 +661,6 @@ read_terminals_fail: /* ===== Cairo ============================================================= */ -static void -push_cairo_object (lua_State *L, LdLuaDrawData *draw_data) -{ - luaL_Reg *fn; - - /* Create a table. */ - lua_newtable (L); - - /* Add methods. */ - /* XXX: The light user data pointer gets invalid after the end of - * "render" function invocation. If the script stores the "cr" object - * in some global variable and then tries to reuse it the next time, - * the application may go SIGSEGV. - * - * The solution is creating a full user data instead, referencing - * the cairo object and dereferencing it upon garbage collection - * of the user data object. - */ - for (fn = ld_lua_cairo_table; fn->name; fn++) - { - lua_pushlightuserdata (L, draw_data); - lua_pushcclosure (L, fn->func, 1); - lua_setfield (L, -2, fn->name); - } -} - static gdouble get_cairo_scale (cairo_t *cr) { @@ -657,6 +670,11 @@ get_cairo_scale (cairo_t *cr) return dx; } +#define LD_LUA_CAIRO_GET_DATA \ + data = luaL_checkudata (L, 1, LD_LUA_META_INDEX); \ + if (!data->cr) \ + return luaL_error (L, "Tried to use an invalid Cairo object"); + #define LD_LUA_CAIRO_BEGIN(name) \ static int \ ld_lua_cairo_ ## name (lua_State *L) \ @@ -669,7 +687,7 @@ ld_lua_cairo_ ## name (lua_State *L) \ #define LD_LUA_CAIRO_TRIVIAL(name) \ LD_LUA_CAIRO_BEGIN (name) \ - data = lua_touserdata (L, lua_upvalueindex (1)); \ + LD_LUA_CAIRO_GET_DATA \ cairo_ ## name (data->cr); \ LD_LUA_CAIRO_END (0) @@ -685,7 +703,7 @@ LD_LUA_CAIRO_TRIVIAL (clip) LD_LUA_CAIRO_TRIVIAL (clip_preserve) LD_LUA_CAIRO_BEGIN (save) - data = lua_touserdata (L, lua_upvalueindex (1)); + LD_LUA_CAIRO_GET_DATA if (data->save_count + 1) { data->save_count++; @@ -694,7 +712,7 @@ LD_LUA_CAIRO_BEGIN (save) LD_LUA_CAIRO_END (0) LD_LUA_CAIRO_BEGIN (restore) - data = lua_touserdata (L, lua_upvalueindex (1)); + LD_LUA_CAIRO_GET_DATA if (data->save_count) { data->save_count--; @@ -703,24 +721,23 @@ LD_LUA_CAIRO_BEGIN (restore) LD_LUA_CAIRO_END (0) LD_LUA_CAIRO_BEGIN (get_line_width) - data = lua_touserdata (L, lua_upvalueindex (1)); + LD_LUA_CAIRO_GET_DATA lua_pushnumber (L, cairo_get_line_width (data->cr) * get_cairo_scale (data->cr)); LD_LUA_CAIRO_END (1) LD_LUA_CAIRO_BEGIN (set_line_width) - data = lua_touserdata (L, lua_upvalueindex (1)); - cairo_set_line_width (data->cr, luaL_checknumber (L, 1) + LD_LUA_CAIRO_GET_DATA + cairo_set_line_width (data->cr, luaL_checknumber (L, 2) / get_cairo_scale (data->cr)); LD_LUA_CAIRO_END (0) LD_LUA_CAIRO_BEGIN (translate) lua_Number x, y; - data = lua_touserdata (L, lua_upvalueindex (1)); - - x = luaL_checknumber (L, 1); - y = luaL_checknumber (L, 2); + LD_LUA_CAIRO_GET_DATA + x = luaL_checknumber (L, 2); + y = luaL_checknumber (L, 3); cairo_translate (data->cr, x, y); LD_LUA_CAIRO_END (0) @@ -728,10 +745,9 @@ LD_LUA_CAIRO_END (0) LD_LUA_CAIRO_BEGIN (scale) lua_Number sx, sy; - data = lua_touserdata (L, lua_upvalueindex (1)); - - sx = luaL_checknumber (L, 1); - sy = luaL_checknumber (L, 2); + LD_LUA_CAIRO_GET_DATA + sx = luaL_checknumber (L, 2); + sy = luaL_checknumber (L, 3); cairo_scale (data->cr, sx, sy); LD_LUA_CAIRO_END (0) @@ -739,18 +755,17 @@ LD_LUA_CAIRO_END (0) LD_LUA_CAIRO_BEGIN (rotate) lua_Number angle; - data = lua_touserdata (L, lua_upvalueindex (1)); - angle = luaL_checknumber (L, 1); + LD_LUA_CAIRO_GET_DATA + angle = luaL_checknumber (L, 2); cairo_rotate (data->cr, angle); LD_LUA_CAIRO_END (0) LD_LUA_CAIRO_BEGIN (move_to) lua_Number x, y; - data = lua_touserdata (L, lua_upvalueindex (1)); - - x = luaL_checknumber (L, 1); - y = luaL_checknumber (L, 2); + LD_LUA_CAIRO_GET_DATA + x = luaL_checknumber (L, 2); + y = luaL_checknumber (L, 3); cairo_move_to (data->cr, x, y); LD_LUA_CAIRO_END (0) @@ -758,10 +773,9 @@ LD_LUA_CAIRO_END (0) LD_LUA_CAIRO_BEGIN (line_to) lua_Number x, y; - data = lua_touserdata (L, lua_upvalueindex (1)); - - x = luaL_checknumber (L, 1); - y = luaL_checknumber (L, 2); + LD_LUA_CAIRO_GET_DATA + x = luaL_checknumber (L, 2); + y = luaL_checknumber (L, 3); cairo_line_to (data->cr, x, y); LD_LUA_CAIRO_END (0) @@ -769,14 +783,13 @@ LD_LUA_CAIRO_END (0) LD_LUA_CAIRO_BEGIN (curve_to) lua_Number x1, y1, x2, y2, x3, y3; - data = lua_touserdata (L, lua_upvalueindex (1)); - - x1 = luaL_checknumber (L, 1); - y1 = luaL_checknumber (L, 2); - x2 = luaL_checknumber (L, 3); - y2 = luaL_checknumber (L, 4); - x3 = luaL_checknumber (L, 5); - y3 = luaL_checknumber (L, 6); + LD_LUA_CAIRO_GET_DATA + x1 = luaL_checknumber (L, 2); + y1 = luaL_checknumber (L, 3); + x2 = luaL_checknumber (L, 4); + y2 = luaL_checknumber (L, 5); + x3 = luaL_checknumber (L, 6); + y3 = luaL_checknumber (L, 7); cairo_curve_to (data->cr, x1, y1, x2, y2, x3, y3); LD_LUA_CAIRO_END (0) @@ -784,13 +797,12 @@ LD_LUA_CAIRO_END (0) LD_LUA_CAIRO_BEGIN (arc) lua_Number xc, yc, radius, angle1, angle2; - data = lua_touserdata (L, lua_upvalueindex (1)); - - xc = luaL_checknumber (L, 1); - yc = luaL_checknumber (L, 2); - radius = luaL_checknumber (L, 3); - angle1 = luaL_checknumber (L, 4); - angle2 = luaL_checknumber (L, 5); + LD_LUA_CAIRO_GET_DATA + xc = luaL_checknumber (L, 2); + yc = luaL_checknumber (L, 3); + radius = luaL_checknumber (L, 4); + angle1 = luaL_checknumber (L, 5); + angle2 = luaL_checknumber (L, 6); cairo_arc (data->cr, xc, yc, radius, angle1, angle2); LD_LUA_CAIRO_END (0) @@ -798,13 +810,12 @@ LD_LUA_CAIRO_END (0) LD_LUA_CAIRO_BEGIN (arc_negative) lua_Number xc, yc, radius, angle1, angle2; - data = lua_touserdata (L, lua_upvalueindex (1)); - - xc = luaL_checknumber (L, 1); - yc = luaL_checknumber (L, 2); - radius = luaL_checknumber (L, 3); - angle1 = luaL_checknumber (L, 4); - angle2 = luaL_checknumber (L, 5); + LD_LUA_CAIRO_GET_DATA + xc = luaL_checknumber (L, 2); + yc = luaL_checknumber (L, 3); + radius = luaL_checknumber (L, 4); + angle1 = luaL_checknumber (L, 5); + angle2 = luaL_checknumber (L, 6); cairo_arc_negative (data->cr, xc, yc, radius, angle1, angle2); LD_LUA_CAIRO_END (0) @@ -816,8 +827,8 @@ LD_LUA_CAIRO_BEGIN (show_text) int width, height; double x, y; - data = lua_touserdata (L, lua_upvalueindex (1)); - text = luaL_checkstring (L, 1); + LD_LUA_CAIRO_GET_DATA + text = luaL_checkstring (L, 2); layout = pango_cairo_create_layout (data->cr); pango_layout_set_text (layout, text, -1); |