X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/2c861050c17237a61fdaff4da2777c5d18ce979a..7eb850ef0e437323e2d84157ddc2e6e82af57bbc:/src/scripting.c diff --git a/src/scripting.c b/src/scripting.c index 2eac840c..35b654f7 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 @@ -166,6 +167,13 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) { redisClient *c = server.lua_client; sds reply; + /* Require at least one argument */ + if (argc == 0) { + luaPushError(lua, + "Please specify at least one argument for redis.call()"); + return 1; + } + /* Build the arguments vector */ argv = zmalloc(sizeof(robj*)*argc); for (j = 0; j < argc; j++) { @@ -206,22 +214,53 @@ 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 @@ -243,11 +282,10 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) { * 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); + c->reply_bytes = 0; cleanup: /* Clean up. Command code may have changed argv/argc so we use the @@ -275,6 +313,25 @@ 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; @@ -342,6 +399,8 @@ 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); @@ -349,7 +408,9 @@ 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); @@ -357,13 +418,59 @@ void luaLoadLibraries(lua_State *lua) { #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. */ void scriptingInit(void) { lua_State *lua = lua_open(); + luaLoadLibraries(lua); + luaRemoveUnsupportedFunctions(lua); /* Initialize a dictionary we use to map SHAs to scripts. * This is useful for replication, as we need to replicate EVALSHA @@ -404,6 +511,11 @@ 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"); @@ -428,7 +540,7 @@ void scriptingInit(void) { " 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; } @@ -456,10 +573,13 @@ 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"; @@ -571,7 +691,7 @@ int luaCreateFunction(redisClient *c, lua_State *lua, char *funcname, robj *body funcdef = sdscatlen(funcdef,body->ptr,sdslen(body->ptr)); funcdef = sdscatlen(funcdef," end",4); - if (luaL_loadbuffer(lua,funcdef,sdslen(funcdef),"func definition")) { + 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); @@ -602,6 +722,7 @@ void evalGenericCommand(redisClient *c, int evalsha) { lua_State *lua = server.lua; char funcname[43]; long long numkeys; + int delhook = 0; /* We want the same PRNG sequence at every call so that our PRNG is * not affected by external state. */ @@ -632,7 +753,7 @@ 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; @@ -672,19 +793,19 @@ 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. */ + server.lua_caller = c; + server.lua_time_start = ustime()/1000; + server.lua_kill = 0; if (server.lua_time_limit > 0 && server.masterhost == NULL) { lua_sethook(lua,luaMaskCountHook,LUA_MASKCOUNT,100000); - } else { - lua_sethook(lua,luaMaskCountHook,0,0); + delhook = 1; } /* 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 (delhook) lua_sethook(lua,luaMaskCountHook,0,0); /* Disable hook */ if (server.lua_timedout) { server.lua_timedout = 0; /* Restore the readable handler that was unregistered when the @@ -700,6 +821,7 @@ void evalGenericCommand(redisClient *c, int evalsha) { lua_gc(lua,LUA_GCCOLLECT,0); return; } + if (delhook) lua_sethook(lua,luaMaskCountHook,0,0); /* Disable hook */ server.lua_timedout = 0; server.lua_caller = NULL; selectDb(c,server.lua_client->db->id); /* set DB ID from Lua client */ @@ -806,7 +928,7 @@ void scriptCommand(redisClient *c) { funcname[0] = 'f'; funcname[1] = '_'; - hashScript(funcname+2,c->argv[2]->ptr,sdslen(c->argv[2]->ptr)); + 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])