X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/070e39454dbe8bcd164e04f7f83da047bd367e22..93a74949d7bb5d0c4115d1bf45f856c368badf31:/src/scripting.c?ds=inline diff --git a/src/scripting.c b/src/scripting.c index 725c123e..4c7de33b 100644 --- a/src/scripting.c +++ b/src/scripting.c @@ -15,6 +15,7 @@ char *redisProtocolToLuaType_Error(lua_State *lua, char *reply); char *redisProtocolToLuaType_MultiBulk(lua_State *lua, char *reply); int redis_math_random (lua_State *L); int redis_math_randomseed (lua_State *L); +void sha1hex(char *digest, char *script, size_t len); /* Take a Redis reply in the Redis protocol format and convert it into a * Lua type. Thanks to this function, and the introduction of not connected @@ -27,7 +28,7 @@ int redis_math_randomseed (lua_State *L); * is like a normal client that bypasses all the slow I/O paths. * * Note: in this function we do not do any sanity check as the reply is - * generated by Redis directly. This allows use to go faster. + * generated by Redis directly. This allows us to go faster. * The reply string can be altered during the parsing as it is discared * after the conversion is completed. * @@ -128,6 +129,37 @@ void luaPushError(lua_State *lua, char *error) { lua_settable(lua,-3); } +/* Sort the array currently in the stack. We do this to make the output + * of commands like KEYS or SMEMBERS something deterministic when called + * from Lua (to play well with AOf/replication). + * + * The array is sorted using table.sort itself, and assuming all the + * list elements are strings. */ +void luaSortArray(lua_State *lua) { + /* Initial Stack: array */ + lua_getglobal(lua,"table"); + lua_pushstring(lua,"sort"); + lua_gettable(lua,-2); /* Stack: array, table, table.sort */ + lua_pushvalue(lua,-3); /* Stack: array, table, table.sort, array */ + if (lua_pcall(lua,1,0,0)) { + /* Stack: array, table, error */ + + /* We are not interested in the error, we assume that the problem is + * that there are 'false' elements inside the array, so we try + * again with a slower function but able to handle this case, that + * is: table.sort(table, __redis__compare_helper) */ + lua_pop(lua,1); /* Stack: array, table */ + lua_pushstring(lua,"sort"); /* Stack: array, table, sort */ + lua_gettable(lua,-2); /* Stack: array, table, table.sort */ + lua_pushvalue(lua,-3); /* Stack: array, table, table.sort, array */ + lua_getglobal(lua,"__redis__compare_helper"); + /* Stack: array, table, table.sort, array, __redis__compare_helper */ + lua_call(lua,2,0); + } + /* Stack: array (sorted), table */ + lua_pop(lua,1); /* Stack: array (sorted) */ +} + int luaRedisGenericCommand(lua_State *lua, int raise_error) { int j, argc = lua_gettop(lua); struct redisCommand *cmd; @@ -175,21 +207,53 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) { goto cleanup; } + /* There are commands that are not allowed inside scripts. */ if (cmd->flags & REDIS_CMD_NOSCRIPT) { luaPushError(lua, "This Redis command is not allowed from scripts"); goto cleanup; } - if (cmd->flags & REDIS_CMD_WRITE && server.lua_random_dirty) { - luaPushError(lua, - "Write commands not allowed after non deterministic commands"); - goto cleanup; + /* Write commands are forbidden against read-only slaves, or if a + * command marked as non-deterministic was already called in the context + * of this script. */ + if (cmd->flags & REDIS_CMD_WRITE) { + if (server.lua_random_dirty) { + luaPushError(lua, + "Write commands not allowed after non deterministic commands"); + goto cleanup; + } else if (server.masterhost && server.repl_slave_ro && + !(server.lua_caller->flags & REDIS_MASTER)) + { + luaPushError(lua, shared.roslaveerr->ptr); + goto cleanup; + } else if (server.stop_writes_on_bgsave_err && + server.saveparamslen > 0 && + server.lastbgsave_status == REDIS_ERR) + { + luaPushError(lua, shared.bgsaveerr->ptr); + goto cleanup; + } + } + + /* If we reached the memory limit configured via maxmemory, commands that + * could enlarge the memory usage are not allowed, but only if this is the + * first write in the context of this script, otherwise we can't stop + * in the middle. */ + if (server.maxmemory && server.lua_write_dirty == 0 && + (cmd->flags & REDIS_CMD_DENYOOM)) + { + if (freeMemoryIfNeeded() == REDIS_ERR) { + luaPushError(lua, shared.oomerr->ptr); + goto cleanup; + } } if (cmd->flags & REDIS_CMD_RANDOM) server.lua_random_dirty = 1; + if (cmd->flags & REDIS_CMD_WRITE) server.lua_write_dirty = 1; /* Run the command */ - cmd->proc(c); + c->cmd = cmd; + call(c,REDIS_CALL_SLOWLOG | REDIS_CALL_STATS); /* Convert the result of the Redis command into a suitable Lua type. * The first thing we need is to create a single string from the client @@ -207,6 +271,14 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) { } if (raise_error && reply[0] != '-') raise_error = 0; redisProtocolToLuaType(lua,reply); + /* Sort the output array if needed, assuming it is a non-null multi bulk + * reply as expected. */ + if ((cmd->flags & REDIS_CMD_SORT_FOR_SCRIPT) && + (reply[0] == '*' && reply[1] != '-')) { + /* Skip this step if command is SORT but output was already sorted */ + if (cmd->proc != sortCommand || server.sort_dontsort) + luaSortArray(lua); + } sdsfree(reply); cleanup: @@ -235,6 +307,25 @@ int luaRedisPCallCommand(lua_State *lua) { return luaRedisGenericCommand(lua,0); } +/* This adds redis.sha1hex(string) to Lua scripts using the same hashing + * function used for sha1ing lua scripts. */ +int luaRedisSha1hexCommand(lua_State *lua) { + int argc = lua_gettop(lua); + char digest[41]; + size_t len; + char *s; + + if (argc != 1) { + luaPushError(lua, "wrong number of arguments"); + return 1; + } + + s = (char*)lua_tolstring(lua,1,&len); + sha1hex(digest,s,len); + lua_pushstring(lua,digest); + return 1; +} + int luaLogCommand(lua_State *lua) { int j, argc = lua_gettop(lua); int level; @@ -273,11 +364,24 @@ int luaLogCommand(lua_State *lua) { 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) { - redisLog(REDIS_NOTICE,"Lua script aborted for max execution time after %lld milliseconds of running time.",elapsed); - lua_pushstring(lua,"Script aborted for max execution time."); + 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); } } @@ -289,6 +393,8 @@ void luaLoadLib(lua_State *lua, const char *libname, lua_CFunction luafunc) { } 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); @@ -296,7 +402,9 @@ void luaLoadLibraries(lua_State *lua) { 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, "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); @@ -304,6 +412,43 @@ void luaLoadLibraries(lua_State *lua) { #endif } +/* 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. @@ -351,6 +496,11 @@ void scriptingInit(void) { lua_pushnumber(lua,REDIS_WARNING); lua_settable(lua,-3); + /* redis.sha1hex */ + lua_pushstring(lua, "sha1hex"); + lua_pushcfunction(lua, luaRedisSha1hexCommand); + lua_settable(lua, -3); + /* Finally set the table as 'redis' global var. */ lua_setglobal(lua,"redis"); @@ -367,6 +517,18 @@ void scriptingInit(void) { lua_setglobal(lua,"math"); + /* Add a helper funciton that we use to sort the multi bulk output of non + * deterministic commands, when containing 'false' elements. */ + { + char *compare_func = "function __redis__compare_helper(a,b)\n" + " if a == false then a = '' end\n" + " if b == false then b = '' end\n" + " return aflags |= REDIS_LUA_CLIENT; } + /* Lua beginners ofter don't use "local", this is likely to introduce + * subtle bugs in their code. To prevent problems we protect accesses + * to global variables. */ + scriptingEnableGlobalsProtection(lua); + server.lua = lua; } @@ -391,10 +558,13 @@ void scriptingReset(void) { scriptingInit(); } -/* Hash the scripit into a SHA1 digest. We use this as Lua function name. - * Digest should point to a 41 bytes buffer: 40 for SHA1 converted into an +/* Perform the SHA1 of the input string. We use this both for hasing script + * bodies in order to obtain the Lua function name, and in the implementation + * of redis.sha1(). + * + * 'digest' should point to a 41 bytes buffer: 40 for SHA1 converted into an * hexadecimal number, plus 1 byte for null term. */ -void hashScript(char *digest, char *script, size_t len) { +void sha1hex(char *digest, char *script, size_t len) { SHA1_CTX ctx; unsigned char hash[20]; char *cset = "0123456789abcdef"; @@ -488,6 +658,51 @@ void luaSetGlobalArray(lua_State *lua, char *var, robj **elev, int elec) { lua_setglobal(lua,var); } +/* Define a lua function with the specified function name and body. + * The function name musts be a 2 characters long string, since all the + * functions we defined in the Lua context are in the form: + * + * f_ + * + * On success REDIS_OK is returned, and nothing is left on the Lua stack. + * On error REDIS_ERR is returned and an appropriate error is set in the + * client context. */ +int luaCreateFunction(redisClient *c, lua_State *lua, char *funcname, robj *body) { + sds funcdef = sdsempty(); + + funcdef = sdscat(funcdef,"function "); + funcdef = sdscatlen(funcdef,funcname,42); + funcdef = sdscatlen(funcdef,"() ",3); + funcdef = sdscatlen(funcdef,body->ptr,sdslen(body->ptr)); + funcdef = sdscatlen(funcdef," end",4); + + if (luaL_loadbuffer(lua,funcdef,sdslen(funcdef),"@user_script")) { + addReplyErrorFormat(c,"Error compiling script (new function): %s\n", + lua_tostring(lua,-1)); + lua_pop(lua,1); + sdsfree(funcdef); + return REDIS_ERR; + } + sdsfree(funcdef); + if (lua_pcall(lua,0,0,0)) { + addReplyErrorFormat(c,"Error running script (new function): %s\n", + lua_tostring(lua,-1)); + lua_pop(lua,1); + return REDIS_ERR; + } + + /* We also save a SHA1 -> Original script map in a dictionary + * so that we can replicate / write in the AOF all the + * EVALSHA commands as EVAL using the original script. */ + { + int retval = dictAdd(server.lua_scripts, + sdsnewlen(funcname+2,40),body); + redisAssertWithInfo(c,NULL,retval == DICT_OK); + incrRefCount(body); + } + return REDIS_OK; +} + void evalGenericCommand(redisClient *c, int evalsha) { lua_State *lua = server.lua; char funcname[43]; @@ -506,6 +721,7 @@ void evalGenericCommand(redisClient *c, int evalsha) { * Thanks to this flag we'll raise an error every time a write command * is called after a random command was used. */ server.lua_random_dirty = 0; + server.lua_write_dirty = 0; /* Get the number of arguments that are keys */ if (getLongLongFromObjectOrReply(c,c->argv[2],&numkeys,NULL) != REDIS_OK) @@ -521,7 +737,7 @@ void evalGenericCommand(redisClient *c, int evalsha) { funcname[1] = '_'; if (!evalsha) { /* Hash the code if this is an EVAL call */ - hashScript(funcname+2,c->argv[1]->ptr,sdslen(c->argv[1]->ptr)); + sha1hex(funcname+2,c->argv[1]->ptr,sdslen(c->argv[1]->ptr)); } else { /* We already have the SHA if it is a EVALSHA */ int j; @@ -532,53 +748,21 @@ void evalGenericCommand(redisClient *c, int evalsha) { funcname[42] = '\0'; } + /* Try to lookup the Lua function */ lua_getglobal(lua, funcname); if (lua_isnil(lua,1)) { - sds funcdef; - + lua_pop(lua,1); /* remove the nil from the stack */ /* Function not defined... let's define it if we have the * body of the funciton. If this is an EVALSHA call we can just * return an error. */ if (evalsha) { addReply(c, shared.noscripterr); - lua_pop(lua,1); /* remove the nil from the stack */ - return; - } - funcdef = sdsempty(); - - lua_pop(lua,1); /* remove the nil from the stack */ - funcdef = sdscat(funcdef,"function "); - funcdef = sdscatlen(funcdef,funcname,42); - funcdef = sdscatlen(funcdef," ()\n",4); - funcdef = sdscatlen(funcdef,c->argv[1]->ptr,sdslen(c->argv[1]->ptr)); - funcdef = sdscatlen(funcdef,"\nend\n",5); - /* printf("Defining:\n%s\n",funcdef); */ - - if (luaL_loadbuffer(lua,funcdef,sdslen(funcdef),"func definition")) { - addReplyErrorFormat(c,"Error compiling script (new function): %s\n", - lua_tostring(lua,-1)); - lua_pop(lua,1); - sdsfree(funcdef); - return; - } - sdsfree(funcdef); - if (lua_pcall(lua,0,0,0)) { - addReplyErrorFormat(c,"Error running script (new function): %s\n", - lua_tostring(lua,-1)); - lua_pop(lua,1); return; } + if (luaCreateFunction(c,lua,funcname,c->argv[1]) == REDIS_ERR) return; + /* Now the following is guaranteed to return non nil */ lua_getglobal(lua, funcname); - - /* We also save a SHA1 -> Original script map in a dictionary - * so that we can replicate / write in the AOF all the - * EVALSHA commands as EVAL using the original script. */ - { - int retval = dictAdd(server.lua_scripts, - sdsnewlen(funcname+2,40),c->argv[1]); - redisAssertWithInfo(c,NULL,retval == DICT_OK); - incrRefCount(c->argv[1]); - } + redisAssert(!lua_isnil(lua,1)); } /* Populate the argv and keys table accordingly to the arguments that @@ -593,9 +777,8 @@ void evalGenericCommand(redisClient *c, int evalsha) { * is running for too much time. * We set the hook only if the time limit is enabled as the hook will * make the Lua script execution slower. */ - if (server.lua_time_limit > 0) { + if (server.lua_time_limit > 0 && server.masterhost == NULL) { lua_sethook(lua,luaMaskCountHook,LUA_MASKCOUNT,100000); - server.lua_time_start = ustime()/1000; } else { lua_sethook(lua,luaMaskCountHook,0,0); } @@ -603,7 +786,18 @@ void evalGenericCommand(redisClient *c, int evalsha) { /* At this point whatever this script was never seen before or if it was * already defined, we can call it. We have zero arguments and expect * a single return value. */ + server.lua_caller = c; + server.lua_time_start = ustime()/1000; + server.lua_kill = 0; if (lua_pcall(lua,0,1,0)) { + if (server.lua_timedout) { + server.lua_timedout = 0; + /* Restore the readable handler that was unregistered when the + * script timeout was detected. */ + aeCreateFileEvent(server.el,c->fd,AE_READABLE, + readQueryFromClient,c); + } + server.lua_caller = NULL; selectDb(c,server.lua_client->db->id); /* set DB ID from Lua client */ addReplyErrorFormat(c,"Error running script (call to %s): %s\n", funcname, lua_tostring(lua,-1)); @@ -611,6 +805,8 @@ void evalGenericCommand(redisClient *c, int evalsha) { lua_gc(lua,LUA_GCCOLLECT,0); return; } + server.lua_timedout = 0; + server.lua_caller = NULL; selectDb(c,server.lua_client->db->id); /* set DB ID from Lua client */ luaReplyToRedisReply(c,lua); lua_gc(lua,LUA_GCSTEP,1); @@ -709,6 +905,32 @@ void scriptCommand(redisClient *c) { else addReply(c,shared.czero); } + } else if (c->argc == 3 && !strcasecmp(c->argv[1]->ptr,"load")) { + char funcname[43]; + sds sha; + + funcname[0] = 'f'; + funcname[1] = '_'; + sha1hex(funcname+2,c->argv[2]->ptr,sdslen(c->argv[2]->ptr)); + sha = sdsnewlen(funcname+2,40); + if (dictFind(server.lua_scripts,sha) == NULL) { + if (luaCreateFunction(c,server.lua,funcname,c->argv[2]) + == REDIS_ERR) { + sdsfree(sha); + return; + } + } + addReplyBulkCBuffer(c,funcname+2,40); + sdsfree(sha); + } else if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"kill")) { + if (server.lua_caller == NULL) { + addReplyError(c,"No scripts in execution right now."); + } else if (server.lua_write_dirty) { + addReplyError(c, "Sorry the script already executed write commands against the dataset. You can either wait the script termination or kill the server in an hard way using the SHUTDOWN NOSAVE command."); + } else { + server.lua_kill = 1; + addReply(c,shared.ok); + } } else { addReplyError(c, "Unknown SCRIPT subcommand or wrong # of args."); }