AP_Scripting: Reduce memory associated with the sandbox

libraries/AP_Scripting/lua/src/lbaselib.c

@@ -452,33 +452,33 @@ static int luaB_tostring (lua_State *L) {
 
 static const luaL_Reg base_funcs[] = {
   {"assert", luaB_assert},
-  {"collectgarbage", luaB_collectgarbage},
-  {"dofile", luaB_dofile},
+//  {"collectgarbage", luaB_collectgarbage},
+//  {"dofile", luaB_dofile},
   {"error", luaB_error},
-  {"getmetatable", luaB_getmetatable},
+//  {"getmetatable", luaB_getmetatable},
   {"ipairs", luaB_ipairs},
-  {"loadfile", luaB_loadfile},
-  {"load", luaB_load},
+//  {"loadfile", luaB_loadfile},
+//  {"load", luaB_load},
 #if defined(LUA_COMPAT_LOADSTRING)
   {"loadstring", luaB_load},
 #endif
   {"next", luaB_next},
   {"pairs", luaB_pairs},
   {"pcall", luaB_pcall},
-  {"print", luaB_print},
-  {"rawequal", luaB_rawequal},
-  {"rawlen", luaB_rawlen},
-  {"rawget", luaB_rawget},
-  {"rawset", luaB_rawset},
-  {"select", luaB_select},
-  {"setmetatable", luaB_setmetatable},
+//  {"print", luaB_print},
+//  {"rawequal", luaB_rawequal},
+//  {"rawlen", luaB_rawlen},
+//  {"rawget", luaB_rawget},
+//  {"rawset", luaB_rawset},
+//  {"select", luaB_select},
+//  {"setmetatable", luaB_setmetatable},
   {"tonumber", luaB_tonumber},
   {"tostring", luaB_tostring},
   {"type", luaB_type},
-  {"xpcall", luaB_xpcall},
+//  {"xpcall", luaB_xpcall},
   /* placeholders */
-  {"_G", NULL},
-  {"_VERSION", NULL},
+//  {"_G", NULL},
+//  {"_VERSION", NULL},
   {NULL, NULL}
 };
 
@@ -496,3 +496,8 @@ LUAMOD_API int luaopen_base (lua_State *L) {
   return 1;
 }
 
+LUAMOD_API int luaopen_base_sandbox(lua_State *L) {
+  luaL_setfuncs(L, base_funcs, 0);
+  return 1;
+}
+

libraries/AP_Scripting/lua/src/liolib.c

@@ -705,9 +705,9 @@ static const luaL_Reg iolib[] = {
   {"lines", io_lines},
   {"open", io_open},
   {"output", io_output},
-  {"popen", io_popen},
+//  {"popen", io_popen},
   {"read", io_read},
-  {"tmpfile", io_tmpfile},
+//  {"tmpfile", io_tmpfile},
   {"type", io_type},
   {"write", io_write},
   {NULL, NULL}

libraries/AP_Scripting/lua/src/lstrlib.c

@@ -1542,7 +1542,7 @@ static int str_unpack (lua_State *L) {
 static const luaL_Reg strlib[] = {
   {"byte", str_byte},
   {"char", str_char},
-  {"dump", str_dump},
+//  {"dump", str_dump},
   {"find", str_find},
   {"format", str_format},
   {"gmatch", gmatch},

libraries/AP_Scripting/lua/src/lualib.h

@@ -16,6 +16,7 @@
 
 
 LUAMOD_API int (luaopen_base) (lua_State *L);
+LUAMOD_API int (luaopen_base_sandbox) (lua_State *L);
 
 #define LUA_COLIBNAME	"coroutine"
 LUAMOD_API int (luaopen_coroutine) (lua_State *L);

libraries/AP_Scripting/lua_bindings.cpp

@@ -52,6 +52,12 @@ static int lua_millis(lua_State *L) {
     return 1;
 }
 
+static const luaL_Reg global_functions[] =
+{
+    {"millis", lua_millis},
+    {NULL, NULL}
+};
+
 static const luaL_Reg servo_functions[] =
 {
     {"set_output_pwm", lua_servo_set_output_pwm},
@@ -59,12 +65,10 @@ static const luaL_Reg servo_functions[] =
 };
 
 void load_lua_bindings(lua_State *L) {
+    lua_pushstring(L, "servo");
     luaL_newlib(L, servo_functions);
-    lua_setglobal(L, "servo");
+    lua_settable(L, -3);
 
-    load_generated_bindings(L);
-
-    lua_pushcfunction(L, lua_millis);
-    lua_setglobal(L, "millis");
+    luaL_setfuncs(L, global_functions, 0);
 }
 

libraries/AP_Scripting/lua_scripts.cpp

@@ -17,7 +17,6 @@
 #include <AP_HAL/AP_HAL.h>
 #include <GCS_MAVLink/GCS.h>
 #include "AP_Scripting.h"
-#include <AP_ROMFS/AP_ROMFS.h>
 
 #include "lua_generated_bindings.h"
 
@@ -94,12 +93,24 @@ lua_scripts::script_info *lua_scripts::load_script(lua_State *L, char *filename)
 
 
     // find and create a sandbox for the new chunk
-    lua_getglobal(L, "get_sandbox_env");
-    if (lua_pcall(L, 0, LUA_MULTRET, 0)) {
-        gcs().send_text(MAV_SEVERITY_CRITICAL, "Scripting: Could not create sandbox: %s", lua_tostring(L, -1));
-        hal.console->printf("Lua: Scripting: Could not create sandbox: %s", lua_tostring(L, -1));
-        return nullptr;
-    }
+    lua_newtable(L);
+    luaopen_base_sandbox(L);
+    lua_pushstring(L, "math");
+    luaopen_math(L);
+    lua_settable(L, -3);
+    lua_pushstring(L, "table");
+    luaopen_table(L);
+    lua_settable(L, -3);
+    lua_pushstring(L, "string");
+    luaopen_string(L);
+    lua_settable(L, -3);
+    lua_pushstring(L, "io");
+    luaopen_io(L);
+    lua_settable(L, -3);
+    lua_pushstring(L, "utf8");
+    luaopen_utf8(L);
+    lua_settable(L, -3);
+    load_lua_bindings(L);
     load_generated_sandbox(L);
     lua_setupvalue(L, -2, 1);
 
@@ -334,22 +345,9 @@ void lua_scripts::run(void) {
         return;
     }
     lua_atpanic(L, atpanic);
-    luaL_openlibs(L);
-    load_lua_bindings(L);
-
-    // load the sandbox creation function
-    uint32_t sandbox_size;
-    const char *sandbox_data = (const char *)AP_ROMFS::find_decompress("sandbox.lua", sandbox_size);
-    if (sandbox_data == nullptr) {
-        gcs().send_text(MAV_SEVERITY_CRITICAL, "Scripting: Could not find sandbox");
-        return;
-    }
-
-    if (luaL_dostring(L, sandbox_data)) {
-        gcs().send_text(MAV_SEVERITY_CRITICAL, "Scripting: Loading sandbox: %s", lua_tostring(L, -1));
-        return;
-    }
-    AP_ROMFS::free((const uint8_t *)sandbox_data);
+//    luaL_openlibs(L);
+//    load_lua_bindings(L);
+    load_generated_bindings(L);
 
     // Scan the filesystem in an appropriate manner and autostart scripts
     load_all_scripts_in_dir(L, SCRIPTING_DIRECTORY);

libraries/AP_Scripting/scripts/sandbox.lua

@@ -1,37 +0,0 @@
--- sample sandbox environment
-function get_sandbox_env ()
-  return {
-          ipairs = ipairs,
-          next = next,
-          pairs = pairs,
-          pcall = pcall,
-          tonumber = tonumber,
-          tostring = tostring,
-          type = type,
-          error = error,
-          unpack = unpack,
-          io = { close = io.close, flush = io.flush, input = io.input, open = io.open, output = io.output,
-                 popen = io.popen, read = io.read, type = io.type, write = io.write},
-          string = { byte = string.byte, char = string.char, find = string.find, 
-                     format = string.format, gmatch = string.gmatch, gsub = string.gsub, 
-                     len = string.len, lower = string.lower, match = string.match, 
-                     rep = string.rep, reverse = string.reverse, sub = string.sub, 
-                     upper = string.upper },
-          math = { abs = math.abs, acos = math.acos, asin = math.asin, 
-                   atan = math.atan, atan2 = math.atan2, ceil = math.ceil, cos = math.cos, 
-                   cosh = math.cosh, deg = math.deg, exp = math.exp, floor = math.floor, 
-                   fmod = math.fmod, frexp = math.frexp, huge = math.huge, 
-                   ldexp = math.ldexp, log = math.log, log10 = math.log10, max = math.max, 
-                   min = math.min, modf = math.modf, pi = math.pi, pow = math.pow, 
-                   rad = math.rad, random = math.random, sin = math.sin, sinh = math.sinh, 
-                   sqrt = math.sqrt, tan = math.tan, tanh = math.tanh },
-          table = { insert = table.insert, maxn = table.maxn, remove = table.remove, 
-                    sort = table.sort, unpack = table.unpack },
-          utf8 = { char = utf8.char, charpattern = utf8.charpattern, codes = utf8.codes,
-                   codepoint = utf8.codepoint, len = utf8.len, offsets = utf8.offsets},
-
-          -- ArduPilot specific
-          millis = millis,
-          servo = { set_output_pwm = servo.set_output_pwm},
-        }
-end