This function installs metamethods in the global table _G that prevent * the creation of globals accidentally. * * It should be the last to be called in the scripting engine initialization * sequence, because it may interact with creation of globals. */
| 1101 | * It should be the last to be called in the scripting engine initialization |
| 1102 | * sequence, because it may interact with creation of globals. */ |
| 1103 | void scriptingEnableGlobalsProtection(lua_State *lua) { |
| 1104 | const char *s[32]; |
| 1105 | sds code = sdsempty(); |
| 1106 | int j = 0; |
| 1107 | |
| 1108 | /* strict.lua from: http://metalua.luaforge.net/src/lib/strict.lua.html. |
| 1109 | * Modified to be adapted to Redis. */ |
| 1110 | s[j++]="local dbg=debug\n"; |
| 1111 | s[j++]="local mt = {}\n"; |
| 1112 | s[j++]="setmetatable(_G, mt)\n"; |
| 1113 | s[j++]="mt.__newindex = function (t, n, v)\n"; |
| 1114 | s[j++]=" if dbg.getinfo(2) then\n"; |
| 1115 | s[j++]=" local w = dbg.getinfo(2, \"S\").what\n"; |
| 1116 | s[j++]=" if w ~= \"main\" and w ~= \"C\" then\n"; |
| 1117 | s[j++]=" error(\"Script attempted to create global variable '\"..tostring(n)..\"'\", 2)\n"; |
| 1118 | s[j++]=" end\n"; |
| 1119 | s[j++]=" end\n"; |
| 1120 | s[j++]=" rawset(t, n, v)\n"; |
| 1121 | s[j++]="end\n"; |
| 1122 | s[j++]="mt.__index = function (t, n)\n"; |
| 1123 | s[j++]=" if dbg.getinfo(2) and dbg.getinfo(2, \"S\").what ~= \"C\" then\n"; |
| 1124 | s[j++]=" error(\"Script attempted to access nonexistent global variable '\"..tostring(n)..\"'\", 2)\n"; |
| 1125 | s[j++]=" end\n"; |
| 1126 | s[j++]=" return rawget(t, n)\n"; |
| 1127 | s[j++]="end\n"; |
| 1128 | s[j++]="debug = nil\n"; |
| 1129 | s[j++]=NULL; |
| 1130 | |
| 1131 | for (j = 0; s[j] != NULL; j++) code = sdscatlen(code,s[j],strlen(s[j])); |
| 1132 | luaL_loadbuffer(lua,code,sdslen(code),"@enable_strict_lua"); |
| 1133 | lua_pcall(lua,0,0,0); |
| 1134 | sdsfree(code); |
| 1135 | } |
| 1136 | |
| 1137 | /* Initialize the scripting environment. |
| 1138 | * |
no test coverage detected