+/* Returns a table with a single field 'field' set to the string value
+ * passed as argument. This helper function is handy when returning
+ * a Redis Protocol error or status reply from Lua:
+ *
+ * return redis.error_reply("ERR Some Error")
+ * return redis.status_reply("ERR Some Error")
+ */
+int luaRedisReturnSingleFieldTable(lua_State *lua, char *field) {
+ if (lua_gettop(lua) != 1 || lua_type(lua,-1) != LUA_TSTRING) {
+ luaPushError(lua, "wrong number or type of arguments");
+ return 1;
+ }
+
+ lua_newtable(lua);
+ lua_pushstring(lua, field);
+ lua_pushvalue(lua, -3);
+ lua_settable(lua, -3);
+ return 1;
+}
+
+int luaRedisErrorReplyCommand(lua_State *lua) {
+ return luaRedisReturnSingleFieldTable(lua,"err");
+}
+
+int luaRedisStatusReplyCommand(lua_State *lua) {
+ return luaRedisReturnSingleFieldTable(lua,"ok");
+}
+
+int luaLogCommand(lua_State *lua) {
+ int j, argc = lua_gettop(lua);
+ int level;
+ sds log;
+
+ if (argc < 2) {
+ luaPushError(lua, "redis.log() requires two arguments or more.");
+ return 1;
+ } else if (!lua_isnumber(lua,-argc)) {
+ luaPushError(lua, "First argument must be a number (log level).");
+ return 1;
+ }
+ level = lua_tonumber(lua,-argc);
+ if (level < REDIS_DEBUG || level > REDIS_WARNING) {
+ luaPushError(lua, "Invalid debug level.");
+ return 1;
+ }
+
+ /* Glue together all the arguments */
+ log = sdsempty();
+ for (j = 1; j < argc; j++) {
+ size_t len;
+ char *s;
+
+ s = (char*)lua_tolstring(lua,(-argc)+j,&len);
+ if (s) {
+ if (j != 1) log = sdscatlen(log," ",1);
+ log = sdscatlen(log,s,len);
+ }
+ }
+ redisLogRaw(level,log);
+ sdsfree(log);
+ return 0;
+}
+
+void luaMaskCountHook(lua_State *lua, lua_Debug *ar) {
+ long long elapsed;
+ REDIS_NOTUSED(ar);
+ REDIS_NOTUSED(lua);
+
+ elapsed = (ustime()/1000) - server.lua_time_start;
+ if (elapsed >= server.lua_time_limit && server.lua_timedout == 0) {
+ redisLog(REDIS_WARNING,"Lua slow script detected: still in execution after %lld milliseconds. You can try killing the script using the SCRIPT KILL command.",elapsed);
+ server.lua_timedout = 1;
+ /* Once the script timeouts we reenter the event loop to permit others
+ * to call SCRIPT KILL or SHUTDOWN NOSAVE if needed. For this reason
+ * we need to mask the client executing the script from the event loop.
+ * If we don't do that the client may disconnect and could no longer be
+ * here when the EVAL command will return. */
+ aeDeleteFileEvent(server.el, server.lua_caller->fd, AE_READABLE);
+ }
+ if (server.lua_timedout)
+ aeProcessEvents(server.el, AE_FILE_EVENTS|AE_DONT_WAIT);
+ if (server.lua_kill) {
+ redisLog(REDIS_WARNING,"Lua script killed by user with SCRIPT KILL.");
+ lua_pushstring(lua,"Script killed by user with SCRIPT KILL...");
+ lua_error(lua);
+ }
+}
+
+void luaLoadLib(lua_State *lua, const char *libname, lua_CFunction luafunc) {
+ lua_pushcfunction(lua, luafunc);
+ lua_pushstring(lua, libname);
+ lua_call(lua, 1, 0);
+}
+
+LUALIB_API int (luaopen_cjson) (lua_State *L);
+LUALIB_API int (luaopen_struct) (lua_State *L);
+LUALIB_API int (luaopen_cmsgpack) (lua_State *L);
+
+void luaLoadLibraries(lua_State *lua) {
+ luaLoadLib(lua, "", luaopen_base);
+ luaLoadLib(lua, LUA_TABLIBNAME, luaopen_table);
+ luaLoadLib(lua, LUA_STRLIBNAME, luaopen_string);
+ luaLoadLib(lua, LUA_MATHLIBNAME, luaopen_math);
+ luaLoadLib(lua, LUA_DBLIBNAME, luaopen_debug);
+ luaLoadLib(lua, "cjson", luaopen_cjson);
+ luaLoadLib(lua, "struct", luaopen_struct);
+ luaLoadLib(lua, "cmsgpack", luaopen_cmsgpack);
+
+#if 0 /* Stuff that we don't load currently, for sandboxing concerns. */
+ luaLoadLib(lua, LUA_LOADLIBNAME, luaopen_package);
+ luaLoadLib(lua, LUA_OSLIBNAME, luaopen_os);
+#endif
+}
+
+/* Remove a functions that we don't want to expose to the Redis scripting
+ * environment. */
+void luaRemoveUnsupportedFunctions(lua_State *lua) {
+ lua_pushnil(lua);
+ lua_setglobal(lua,"loadfile");
+}
+
+/* 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. */
+void scriptingEnableGlobalsProtection(lua_State *lua) {
+ char *s[32];
+ sds code = sdsempty();
+ int j = 0;
+
+ /* strict.lua from: http://metalua.luaforge.net/src/lib/strict.lua.html.
+ * Modified to be adapted to Redis. */
+ s[j++]="local mt = {}\n";
+ s[j++]="setmetatable(_G, mt)\n";
+ s[j++]="mt.__newindex = function (t, n, v)\n";
+ s[j++]=" if debug.getinfo(2) then\n";
+ s[j++]=" local w = debug.getinfo(2, \"S\").what\n";
+ s[j++]=" if w ~= \"main\" and w ~= \"C\" then\n";
+ s[j++]=" error(\"Script attempted to create global variable '\"..tostring(n)..\"'\", 2)\n";
+ s[j++]=" end\n";
+ s[j++]=" end\n";
+ s[j++]=" rawset(t, n, v)\n";
+ s[j++]="end\n";
+ s[j++]="mt.__index = function (t, n)\n";
+ s[j++]=" if debug.getinfo(2) and debug.getinfo(2, \"S\").what ~= \"C\" then\n";
+ s[j++]=" error(\"Script attempted to access unexisting global variable '\"..tostring(n)..\"'\", 2)\n";
+ s[j++]=" end\n";
+ s[j++]=" return rawget(t, n)\n";
+ s[j++]="end\n";
+ s[j++]=NULL;
+
+ for (j = 0; s[j] != NULL; j++) code = sdscatlen(code,s[j],strlen(s[j]));
+ luaL_loadbuffer(lua,code,sdslen(code),"@enable_strict_lua");
+ lua_pcall(lua,0,0,0);
+ sdsfree(code);
+}
+
+/* Initialize the scripting environment.
+ * It is possible to call this function to reset the scripting environment
+ * assuming that we call scriptingRelease() before.
+ * See scriptingReset() for more information. */
projects / redis.git / blobdiff