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script_lua.c
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script_lua.c
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/*
* Copyright (c) 2009-2021, Redis Ltd.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Redis nor the names of its contributors may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "script_lua.h"
#include "fpconv_dtoa.h"
#include "server.h"
#include "sha1.h"
#include "rand.h"
#include "cluster.h"
#include "monotonic.h"
#include "resp_parser.h"
#include "version.h"
#include <lauxlib.h>
#include <lualib.h>
#include <ctype.h>
#include <math.h>
/* Globals that are added by the Lua libraries */
static char *libraries_allow_list[] = {
"string", "cjson", "bit", "cmsgpack", "math", "table", "struct", "os", NULL,
};
/* Lua API globals */
static char *redis_api_allow_list[] = {
SERVER_API_NAME,
REDIS_API_NAME,
"__redis__err__handler", /* error handler for eval, currently located on globals.
Should move to registry. */
NULL,
};
/* Lua builtins */
static char *lua_builtins_allow_list[] = {
"xpcall", "tostring", "getfenv", "setmetatable", "next", "assert", "tonumber",
"rawequal", "collectgarbage", "getmetatable", "rawset", "pcall", "coroutine", "type",
"_G", "select", "unpack", "gcinfo", "pairs", "rawget", "loadstring",
"ipairs", "_VERSION", "setfenv", "load", "error", NULL,
};
/* Lua builtins which are not documented on the Lua documentation */
static char *lua_builtins_not_documented_allow_list[] = {
"newproxy",
NULL,
};
/* Lua builtins which are allowed on initialization but will be removed right after */
static char *lua_builtins_removed_after_initialization_allow_list[] = {
"debug", /* debug will be set to nil after the error handler will be created */
NULL,
};
/* Those allow lists was created from the globals that was
* available to the user when the allow lists was first introduce.
* Because we do not want to break backward compatibility we keep
* all the globals. The allow lists will prevent us from accidentally
* creating unwanted globals in the future.
*
* Also notice that the allow list is only checked on start time,
* after that the global table is locked so not need to check anything.*/
static char **allow_lists[] = {
libraries_allow_list,
redis_api_allow_list,
lua_builtins_allow_list,
lua_builtins_not_documented_allow_list,
lua_builtins_removed_after_initialization_allow_list,
NULL,
};
/* Deny list contains elements which we know we do not want to add to globals
* and there is no need to print a warning message form them. We will print a
* log message only if an element was added to the globals and the element is
* not on the allow list nor on the back list. */
static char *deny_list[] = {
"dofile",
"loadfile",
"print",
NULL,
};
static int redis_math_random(lua_State *L);
static int redis_math_randomseed(lua_State *L);
static void redisProtocolToLuaType_Int(void *ctx, long long val, const char *proto, size_t proto_len);
static void
redisProtocolToLuaType_BulkString(void *ctx, const char *str, size_t len, const char *proto, size_t proto_len);
static void redisProtocolToLuaType_NullBulkString(void *ctx, const char *proto, size_t proto_len);
static void redisProtocolToLuaType_NullArray(void *ctx, const char *proto, size_t proto_len);
static void redisProtocolToLuaType_Status(void *ctx, const char *str, size_t len, const char *proto, size_t proto_len);
static void redisProtocolToLuaType_Error(void *ctx, const char *str, size_t len, const char *proto, size_t proto_len);
static void redisProtocolToLuaType_Array(struct ReplyParser *parser, void *ctx, size_t len, const char *proto);
static void redisProtocolToLuaType_Map(struct ReplyParser *parser, void *ctx, size_t len, const char *proto);
static void redisProtocolToLuaType_Set(struct ReplyParser *parser, void *ctx, size_t len, const char *proto);
static void redisProtocolToLuaType_Null(void *ctx, const char *proto, size_t proto_len);
static void redisProtocolToLuaType_Bool(void *ctx, int val, const char *proto, size_t proto_len);
static void redisProtocolToLuaType_Double(void *ctx, double d, const char *proto, size_t proto_len);
static void
redisProtocolToLuaType_BigNumber(void *ctx, const char *str, size_t len, const char *proto, size_t proto_len);
static void redisProtocolToLuaType_VerbatimString(void *ctx,
const char *format,
const char *str,
size_t len,
const char *proto,
size_t proto_len);
static void redisProtocolToLuaType_Attribute(struct ReplyParser *parser, void *ctx, size_t len, const char *proto);
static void luaReplyToRedisReply(client *c, client *script_client, lua_State *lua);
/*
* Save the give pointer on Lua registry, used to save the Lua context and
* function context so we can retrieve them from lua_State.
*/
void luaSaveOnRegistry(lua_State *lua, const char *name, void *ptr) {
lua_pushstring(lua, name);
if (ptr) {
lua_pushlightuserdata(lua, ptr);
} else {
lua_pushnil(lua);
}
lua_settable(lua, LUA_REGISTRYINDEX);
}
/*
* Get a saved pointer from registry
*/
void *luaGetFromRegistry(lua_State *lua, const char *name) {
lua_pushstring(lua, name);
lua_gettable(lua, LUA_REGISTRYINDEX);
if (lua_isnil(lua, -1)) {
lua_pop(lua, 1); /* pops the value */
return NULL;
}
/* must be light user data */
serverAssert(lua_islightuserdata(lua, -1));
void *ptr = (void *)lua_topointer(lua, -1);
serverAssert(ptr);
/* pops the value */
lua_pop(lua, 1);
return ptr;
}
/* ---------------------------------------------------------------------------
* Server reply to Lua type conversion functions.
* ------------------------------------------------------------------------- */
/* Take a server reply in the RESP format and convert it into a
* Lua type. Thanks to this function, and the introduction of not connected
* clients, it is trivial to implement the redis() lua function.
*
* Basically we take the arguments, execute the command in the context
* of a non connected client, then take the generated reply and convert it
* into a suitable Lua type. With this trick the scripting feature does not
* need the introduction of a full server internals API. The script
* 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 the server directly. This allows us to go faster.
*
* Errors are returned as a table with a single 'err' field set to the
* error string.
*/
static const ReplyParserCallbacks DefaultLuaTypeParserCallbacks = {
.null_array_callback = redisProtocolToLuaType_NullArray,
.bulk_string_callback = redisProtocolToLuaType_BulkString,
.null_bulk_string_callback = redisProtocolToLuaType_NullBulkString,
.error_callback = redisProtocolToLuaType_Error,
.simple_str_callback = redisProtocolToLuaType_Status,
.long_callback = redisProtocolToLuaType_Int,
.array_callback = redisProtocolToLuaType_Array,
.set_callback = redisProtocolToLuaType_Set,
.map_callback = redisProtocolToLuaType_Map,
.bool_callback = redisProtocolToLuaType_Bool,
.double_callback = redisProtocolToLuaType_Double,
.null_callback = redisProtocolToLuaType_Null,
.big_number_callback = redisProtocolToLuaType_BigNumber,
.verbatim_string_callback = redisProtocolToLuaType_VerbatimString,
.attribute_callback = redisProtocolToLuaType_Attribute,
.error = NULL,
};
static void redisProtocolToLuaType(lua_State *lua, char *reply) {
ReplyParser parser = {.curr_location = reply, .callbacks = DefaultLuaTypeParserCallbacks};
parseReply(&parser, lua);
}
static void redisProtocolToLuaType_Int(void *ctx, long long val, const char *proto, size_t proto_len) {
UNUSED(proto);
UNUSED(proto_len);
if (!ctx) {
return;
}
lua_State *lua = ctx;
if (!lua_checkstack(lua, 1)) {
/* Increase the Lua stack if needed, to make sure there is enough room
* to push elements to the stack. On failure, exit with panic. */
serverPanic("lua stack limit reach when parsing server.call reply");
}
lua_pushnumber(lua, (lua_Number)val);
}
static void redisProtocolToLuaType_NullBulkString(void *ctx, const char *proto, size_t proto_len) {
UNUSED(proto);
UNUSED(proto_len);
if (!ctx) {
return;
}
lua_State *lua = ctx;
if (!lua_checkstack(lua, 1)) {
/* Increase the Lua stack if needed, to make sure there is enough room
* to push elements to the stack. On failure, exit with panic. */
serverPanic("lua stack limit reach when parsing server.call reply");
}
lua_pushboolean(lua, 0);
}
static void redisProtocolToLuaType_NullArray(void *ctx, const char *proto, size_t proto_len) {
UNUSED(proto);
UNUSED(proto_len);
if (!ctx) {
return;
}
lua_State *lua = ctx;
if (!lua_checkstack(lua, 1)) {
/* Increase the Lua stack if needed, to make sure there is enough room
* to push elements to the stack. On failure, exit with panic. */
serverPanic("lua stack limit reach when parsing server.call reply");
}
lua_pushboolean(lua, 0);
}
static void
redisProtocolToLuaType_BulkString(void *ctx, const char *str, size_t len, const char *proto, size_t proto_len) {
UNUSED(proto);
UNUSED(proto_len);
if (!ctx) {
return;
}
lua_State *lua = ctx;
if (!lua_checkstack(lua, 1)) {
/* Increase the Lua stack if needed, to make sure there is enough room
* to push elements to the stack. On failure, exit with panic. */
serverPanic("lua stack limit reach when parsing server.call reply");
}
lua_pushlstring(lua, str, len);
}
static void redisProtocolToLuaType_Status(void *ctx, const char *str, size_t len, const char *proto, size_t proto_len) {
UNUSED(proto);
UNUSED(proto_len);
if (!ctx) {
return;
}
lua_State *lua = ctx;
if (!lua_checkstack(lua, 3)) {
/* Increase the Lua stack if needed, to make sure there is enough room
* to push elements to the stack. On failure, exit with panic. */
serverPanic("lua stack limit reach when parsing server.call reply");
}
lua_newtable(lua);
lua_pushstring(lua, "ok");
lua_pushlstring(lua, str, len);
lua_settable(lua, -3);
}
static void redisProtocolToLuaType_Error(void *ctx, const char *str, size_t len, const char *proto, size_t proto_len) {
UNUSED(proto);
UNUSED(proto_len);
if (!ctx) {
return;
}
lua_State *lua = ctx;
if (!lua_checkstack(lua, 3)) {
/* Increase the Lua stack if needed, to make sure there is enough room
* to push elements to the stack. On failure, exit with panic. */
serverPanic("lua stack limit reach when parsing server.call reply");
}
sds err_msg = sdscatlen(sdsnew("-"), str, len);
luaPushErrorBuff(lua, err_msg);
/* push a field indicate to ignore updating the stats on this error
* because it was already updated when executing the command. */
lua_pushstring(lua, "ignore_error_stats_update");
lua_pushboolean(lua, 1);
lua_settable(lua, -3);
}
static void redisProtocolToLuaType_Map(struct ReplyParser *parser, void *ctx, size_t len, const char *proto) {
UNUSED(proto);
lua_State *lua = ctx;
if (lua) {
if (!lua_checkstack(lua, 3)) {
/* Increase the Lua stack if needed, to make sure there is enough room
* to push elements to the stack. On failure, exit with panic. */
serverPanic("lua stack limit reach when parsing server.call reply");
}
lua_newtable(lua);
lua_pushstring(lua, "map");
lua_newtable(lua);
}
for (size_t j = 0; j < len; j++) {
parseReply(parser, lua);
parseReply(parser, lua);
if (lua) lua_settable(lua, -3);
}
if (lua) lua_settable(lua, -3);
}
static void redisProtocolToLuaType_Set(struct ReplyParser *parser, void *ctx, size_t len, const char *proto) {
UNUSED(proto);
lua_State *lua = ctx;
if (lua) {
if (!lua_checkstack(lua, 3)) {
/* Increase the Lua stack if needed, to make sure there is enough room
* to push elements to the stack. On failure, exit with panic. */
serverPanic("lua stack limit reach when parsing server.call reply");
}
lua_newtable(lua);
lua_pushstring(lua, "set");
lua_newtable(lua);
}
for (size_t j = 0; j < len; j++) {
parseReply(parser, lua);
if (lua) {
if (!lua_checkstack(lua, 1)) {
/* Increase the Lua stack if needed, to make sure there is enough room
* to push elements to the stack. On failure, exit with panic.
* Notice that here we need to check the stack again because the recursive
* call to redisProtocolToLuaType might have use the room allocated in the stack*/
serverPanic("lua stack limit reach when parsing server.call reply");
}
lua_pushboolean(lua, 1);
lua_settable(lua, -3);
}
}
if (lua) lua_settable(lua, -3);
}
static void redisProtocolToLuaType_Array(struct ReplyParser *parser, void *ctx, size_t len, const char *proto) {
UNUSED(proto);
lua_State *lua = ctx;
if (lua) {
if (!lua_checkstack(lua, 2)) {
/* Increase the Lua stack if needed, to make sure there is enough room
* to push elements to the stack. On failure, exit with panic. */
serverPanic("lua stack limit reach when parsing server.call reply");
}
lua_newtable(lua);
}
for (size_t j = 0; j < len; j++) {
if (lua) lua_pushnumber(lua, j + 1);
parseReply(parser, lua);
if (lua) lua_settable(lua, -3);
}
}
static void redisProtocolToLuaType_Attribute(struct ReplyParser *parser, void *ctx, size_t len, const char *proto) {
UNUSED(proto);
/* Parse the attribute reply.
* Currently, we do not expose the attribute to the Lua script so
* we just need to continue parsing and ignore it (the NULL ensures that the
* reply will be ignored). */
for (size_t j = 0; j < len; j++) {
parseReply(parser, NULL);
parseReply(parser, NULL);
}
/* Parse the reply itself. */
parseReply(parser, ctx);
}
static void redisProtocolToLuaType_VerbatimString(void *ctx,
const char *format,
const char *str,
size_t len,
const char *proto,
size_t proto_len) {
UNUSED(proto);
UNUSED(proto_len);
if (!ctx) {
return;
}
lua_State *lua = ctx;
if (!lua_checkstack(lua, 5)) {
/* Increase the Lua stack if needed, to make sure there is enough room
* to push elements to the stack. On failure, exit with panic. */
serverPanic("lua stack limit reach when parsing server.call reply");
}
lua_newtable(lua);
lua_pushstring(lua, "verbatim_string");
lua_newtable(lua);
lua_pushstring(lua, "string");
lua_pushlstring(lua, str, len);
lua_settable(lua, -3);
lua_pushstring(lua, "format");
lua_pushlstring(lua, format, 3);
lua_settable(lua, -3);
lua_settable(lua, -3);
}
static void
redisProtocolToLuaType_BigNumber(void *ctx, const char *str, size_t len, const char *proto, size_t proto_len) {
UNUSED(proto);
UNUSED(proto_len);
if (!ctx) {
return;
}
lua_State *lua = ctx;
if (!lua_checkstack(lua, 3)) {
/* Increase the Lua stack if needed, to make sure there is enough room
* to push elements to the stack. On failure, exit with panic. */
serverPanic("lua stack limit reach when parsing server.call reply");
}
lua_newtable(lua);
lua_pushstring(lua, "big_number");
lua_pushlstring(lua, str, len);
lua_settable(lua, -3);
}
static void redisProtocolToLuaType_Null(void *ctx, const char *proto, size_t proto_len) {
UNUSED(proto);
UNUSED(proto_len);
if (!ctx) {
return;
}
lua_State *lua = ctx;
if (!lua_checkstack(lua, 1)) {
/* Increase the Lua stack if needed, to make sure there is enough room
* to push elements to the stack. On failure, exit with panic. */
serverPanic("lua stack limit reach when parsing server.call reply");
}
lua_pushnil(lua);
}
static void redisProtocolToLuaType_Bool(void *ctx, int val, const char *proto, size_t proto_len) {
UNUSED(proto);
UNUSED(proto_len);
if (!ctx) {
return;
}
lua_State *lua = ctx;
if (!lua_checkstack(lua, 1)) {
/* Increase the Lua stack if needed, to make sure there is enough room
* to push elements to the stack. On failure, exit with panic. */
serverPanic("lua stack limit reach when parsing server.call reply");
}
lua_pushboolean(lua, val);
}
static void redisProtocolToLuaType_Double(void *ctx, double d, const char *proto, size_t proto_len) {
UNUSED(proto);
UNUSED(proto_len);
if (!ctx) {
return;
}
lua_State *lua = ctx;
if (!lua_checkstack(lua, 3)) {
/* Increase the Lua stack if needed, to make sure there is enough room
* to push elements to the stack. On failure, exit with panic. */
serverPanic("lua stack limit reach when parsing server.call reply");
}
lua_newtable(lua);
lua_pushstring(lua, "double");
lua_pushnumber(lua, d);
lua_settable(lua, -3);
}
/* This function is used in order to push an error on the Lua stack in the
* format used by server.pcall to return errors, which is a lua table
* with an "err" field set to the error string including the error code.
* Note that this table is never a valid reply by proper commands,
* since the returned tables are otherwise always indexed by integers, never by strings.
*
* The function takes ownership on the given err_buffer. */
void luaPushErrorBuff(lua_State *lua, sds err_buffer) {
sds msg;
sds error_code;
/* If debugging is active and in step mode, log errors resulting from
* server commands. */
if (ldbIsEnabled()) {
ldbLog(sdscatprintf(sdsempty(), "<error> %s", err_buffer));
}
/* There are two possible formats for the received `error` string:
* 1) "-CODE msg": in this case we remove the leading '-' since we don't store it as part of the lua error format.
* 2) "msg": in this case we prepend a generic 'ERR' code since all error statuses need some error code.
* We support format (1) so this function can reuse the error messages used in other places.
* We support format (2) so it'll be easy to pass descriptive errors to this function without worrying about format.
*/
if (err_buffer[0] == '-') {
/* derive error code from the message */
char *err_msg = strstr(err_buffer, " ");
if (!err_msg) {
msg = sdsnew(err_buffer + 1);
error_code = sdsnew("ERR");
} else {
*err_msg = '\0';
msg = sdsnew(err_msg + 1);
error_code = sdsnew(err_buffer + 1);
}
sdsfree(err_buffer);
} else {
msg = err_buffer;
error_code = sdsnew("ERR");
}
/* Trim newline at end of string. If we reuse the ready-made error objects (case 1 above) then we might
* have a newline that needs to be trimmed. In any case the lua server error table shouldn't end with a newline. */
msg = sdstrim(msg, "\r\n");
sds final_msg = sdscatfmt(error_code, " %s", msg);
lua_newtable(lua);
lua_pushstring(lua, "err");
lua_pushstring(lua, final_msg);
lua_settable(lua, -3);
sdsfree(msg);
sdsfree(final_msg);
}
void luaPushError(lua_State *lua, const char *error) {
luaPushErrorBuff(lua, sdsnew(error));
}
/* In case the error set into the Lua stack by luaPushError() was generated
* by the non-error-trapping version of server.pcall(), which is server.call(),
* this function will raise the Lua error so that the execution of the
* script will be halted. */
int luaError(lua_State *lua) {
return lua_error(lua);
}
/* ---------------------------------------------------------------------------
* Lua reply to server reply conversion functions.
* ------------------------------------------------------------------------- */
/* Reply to client 'c' converting the top element in the Lua stack to a
* server reply. As a side effect the element is consumed from the stack. */
static void luaReplyToRedisReply(client *c, client *script_client, lua_State *lua) {
int t = lua_type(lua, -1);
if (!lua_checkstack(lua, 4)) {
/* Increase the Lua stack if needed to make sure there is enough room
* to push 4 elements to the stack. On failure, return error.
* Notice that we need, in the worst case, 4 elements because returning a map might
* require push 4 elements to the Lua stack.*/
addReplyError(c, "reached lua stack limit");
lua_pop(lua, 1); /* pop the element from the stack */
return;
}
switch (t) {
case LUA_TSTRING: addReplyBulkCBuffer(c, (char *)lua_tostring(lua, -1), lua_strlen(lua, -1)); break;
case LUA_TBOOLEAN:
if (script_client->resp == 2)
addReply(c, lua_toboolean(lua, -1) ? shared.cone : shared.null[c->resp]);
else
addReplyBool(c, lua_toboolean(lua, -1));
break;
case LUA_TNUMBER: addReplyLongLong(c, (long long)lua_tonumber(lua, -1)); break;
case LUA_TTABLE:
/* We need to check if it is an array, an error, or a status reply.
* Error are returned as a single element table with 'err' field.
* Status replies are returned as single element table with 'ok'
* field. */
/* Handle error reply. */
/* we took care of the stack size on function start */
lua_pushstring(lua, "err");
lua_rawget(lua, -2);
t = lua_type(lua, -1);
if (t == LUA_TSTRING) {
lua_pop(lua,
1); /* pop the error message, we will use luaExtractErrorInformation to get error information */
errorInfo err_info = {0};
luaExtractErrorInformation(lua, &err_info);
addReplyErrorFormatEx(
c, ERR_REPLY_FLAG_CUSTOM | (err_info.ignore_err_stats_update ? ERR_REPLY_FLAG_NO_STATS_UPDATE : 0),
"-%s", err_info.msg);
luaErrorInformationDiscard(&err_info);
lua_pop(lua, 1); /* pop the result table */
return;
}
lua_pop(lua, 1); /* Discard field name pushed before. */
/* Handle status reply. */
lua_pushstring(lua, "ok");
lua_rawget(lua, -2);
t = lua_type(lua, -1);
if (t == LUA_TSTRING) {
sds ok = sdsnew(lua_tostring(lua, -1));
sdsmapchars(ok, "\r\n", " ", 2);
addReplyStatusLength(c, ok, sdslen(ok));
sdsfree(ok);
lua_pop(lua, 2);
return;
}
lua_pop(lua, 1); /* Discard field name pushed before. */
/* Handle double reply. */
lua_pushstring(lua, "double");
lua_rawget(lua, -2);
t = lua_type(lua, -1);
if (t == LUA_TNUMBER) {
addReplyDouble(c, lua_tonumber(lua, -1));
lua_pop(lua, 2);
return;
}
lua_pop(lua, 1); /* Discard field name pushed before. */
/* Handle big number reply. */
lua_pushstring(lua, "big_number");
lua_rawget(lua, -2);
t = lua_type(lua, -1);
if (t == LUA_TSTRING) {
sds big_num = sdsnewlen(lua_tostring(lua, -1), lua_strlen(lua, -1));
sdsmapchars(big_num, "\r\n", " ", 2);
addReplyBigNum(c, big_num, sdslen(big_num));
sdsfree(big_num);
lua_pop(lua, 2);
return;
}
lua_pop(lua, 1); /* Discard field name pushed before. */
/* Handle verbatim reply. */
lua_pushstring(lua, "verbatim_string");
lua_rawget(lua, -2);
t = lua_type(lua, -1);
if (t == LUA_TTABLE) {
lua_pushstring(lua, "format");
lua_rawget(lua, -2);
t = lua_type(lua, -1);
if (t == LUA_TSTRING) {
char *format = (char *)lua_tostring(lua, -1);
lua_pushstring(lua, "string");
lua_rawget(lua, -3);
t = lua_type(lua, -1);
if (t == LUA_TSTRING) {
size_t len;
char *str = (char *)lua_tolstring(lua, -1, &len);
addReplyVerbatim(c, str, len, format);
lua_pop(lua, 4);
return;
}
lua_pop(lua, 1);
}
lua_pop(lua, 1);
}
lua_pop(lua, 1); /* Discard field name pushed before. */
/* Handle map reply. */
lua_pushstring(lua, "map");
lua_rawget(lua, -2);
t = lua_type(lua, -1);
if (t == LUA_TTABLE) {
int maplen = 0;
void *replylen = addReplyDeferredLen(c);
/* we took care of the stack size on function start */
lua_pushnil(lua); /* Use nil to start iteration. */
while (lua_next(lua, -2)) {
/* Stack now: table, key, value */
lua_pushvalue(lua, -2); /* Dup key before consuming. */
luaReplyToRedisReply(c, script_client, lua); /* Return key. */
luaReplyToRedisReply(c, script_client, lua); /* Return value. */
/* Stack now: table, key. */
maplen++;
}
setDeferredMapLen(c, replylen, maplen);
lua_pop(lua, 2);
return;
}
lua_pop(lua, 1); /* Discard field name pushed before. */
/* Handle set reply. */
lua_pushstring(lua, "set");
lua_rawget(lua, -2);
t = lua_type(lua, -1);
if (t == LUA_TTABLE) {
int setlen = 0;
void *replylen = addReplyDeferredLen(c);
/* we took care of the stack size on function start */
lua_pushnil(lua); /* Use nil to start iteration. */
while (lua_next(lua, -2)) {
/* Stack now: table, key, true */
lua_pop(lua, 1); /* Discard the boolean value. */
lua_pushvalue(lua, -1); /* Dup key before consuming. */
luaReplyToRedisReply(c, script_client, lua); /* Return key. */
/* Stack now: table, key. */
setlen++;
}
setDeferredSetLen(c, replylen, setlen);
lua_pop(lua, 2);
return;
}
lua_pop(lua, 1); /* Discard field name pushed before. */
/* Handle the array reply. */
void *replylen = addReplyDeferredLen(c);
int j = 1, mbulklen = 0;
while (1) {
/* we took care of the stack size on function start */
lua_pushnumber(lua, j++);
lua_rawget(lua, -2);
t = lua_type(lua, -1);
if (t == LUA_TNIL) {
lua_pop(lua, 1);
break;
}
luaReplyToRedisReply(c, script_client, lua);
mbulklen++;
}
setDeferredArrayLen(c, replylen, mbulklen);
break;
default: addReplyNull(c);
}
lua_pop(lua, 1);
}
/* ---------------------------------------------------------------------------
* Lua server.* functions implementations.
* ------------------------------------------------------------------------- */
void freeLuaRedisArgv(robj **argv, int argc, int argv_len);
/* Cached argv array across calls. */
static robj **lua_argv = NULL;
static int lua_argv_size = 0;
/* Cache of recently used small arguments to avoid malloc calls. */
static robj *lua_args_cached_objects[LUA_CMD_OBJCACHE_SIZE];
static size_t lua_args_cached_objects_len[LUA_CMD_OBJCACHE_SIZE];
static robj **luaArgsToRedisArgv(lua_State *lua, int *argc, int *argv_len) {
int j;
/* Require at least one argument */
*argc = lua_gettop(lua);
if (*argc == 0) {
luaPushError(lua, "Please specify at least one argument for this call");
return NULL;
}
/* Build the arguments vector (reuse a cached argv from last call) */
if (lua_argv_size < *argc) {
lua_argv = zrealloc(lua_argv, sizeof(robj *) * *argc);
lua_argv_size = *argc;
}
*argv_len = lua_argv_size;
for (j = 0; j < *argc; j++) {
char *obj_s;
size_t obj_len;
char dbuf[64];
if (lua_type(lua, j + 1) == LUA_TNUMBER) {
/* We can't use lua_tolstring() for number -> string conversion
* since Lua uses a format specifier that loses precision. */
lua_Number num = lua_tonumber(lua, j + 1);
/* Integer printing function is much faster, check if we can safely use it.
* Since lua_Number is not explicitly an integer or a double, we need to make an effort
* to convert it as an integer when that's possible, since the string could later be used
* in a context that doesn't support scientific notation (e.g. 1e9 instead of 100000000). */
long long lvalue;
if (double2ll((double)num, &lvalue))
obj_len = ll2string(dbuf, sizeof(dbuf), lvalue);
else {
obj_len = fpconv_dtoa((double)num, dbuf);
dbuf[obj_len] = '\0';
}
obj_s = dbuf;
} else {
obj_s = (char *)lua_tolstring(lua, j + 1, &obj_len);
if (obj_s == NULL) break; /* Not a string. */
}
/* Try to use a cached object. */
if (j < LUA_CMD_OBJCACHE_SIZE && lua_args_cached_objects[j] && lua_args_cached_objects_len[j] >= obj_len) {
sds s = lua_args_cached_objects[j]->ptr;
lua_argv[j] = lua_args_cached_objects[j];
lua_args_cached_objects[j] = NULL;
memcpy(s, obj_s, obj_len + 1);
sdssetlen(s, obj_len);
} else {
lua_argv[j] = createStringObject(obj_s, obj_len);
}
}
/* Pop all arguments from the stack, we do not need them anymore
* and this way we guaranty we will have room on the stack for the result. */
lua_pop(lua, *argc);
/* Check if one of the arguments passed by the Lua script
* is not a string or an integer (lua_isstring() return true for
* integers as well). */
if (j != *argc) {
freeLuaRedisArgv(lua_argv, j, lua_argv_size);
luaPushError(lua, "Command arguments must be strings or integers");
return NULL;
}
return lua_argv;
}
void freeLuaRedisArgv(robj **argv, int argc, int argv_len) {
int j;
for (j = 0; j < argc; j++) {
robj *o = argv[j];
/* Try to cache the object in the lua_args_cached_objects array.
* The object must be small, SDS-encoded, and with refcount = 1
* (we must be the only owner) for us to cache it. */
if (j < LUA_CMD_OBJCACHE_SIZE && o->refcount == 1 &&
(o->encoding == OBJ_ENCODING_RAW || o->encoding == OBJ_ENCODING_EMBSTR) &&
sdslen(o->ptr) <= LUA_CMD_OBJCACHE_MAX_LEN) {
sds s = o->ptr;
if (lua_args_cached_objects[j]) decrRefCount(lua_args_cached_objects[j]);
lua_args_cached_objects[j] = o;
lua_args_cached_objects_len[j] = sdsalloc(s);
} else {
decrRefCount(o);
}
}
if (argv != lua_argv || argv_len != lua_argv_size) {
/* The command changed argv, scrap the cache and start over. */
zfree(argv);
lua_argv = NULL;
lua_argv_size = 0;
}
}
static int luaRedisGenericCommand(lua_State *lua, int raise_error) {
int j;
scriptRunCtx *rctx = luaGetFromRegistry(lua, REGISTRY_RUN_CTX_NAME);
serverAssert(rctx); /* Only supported inside script invocation */
sds err = NULL;
client *c = rctx->c;
sds reply;
c->argv = luaArgsToRedisArgv(lua, &c->argc, &c->argv_len);
if (c->argv == NULL) {
return raise_error ? luaError(lua) : 1;
}
static int inuse = 0; /* Recursive calls detection. */
/* By using Lua debug hooks it is possible to trigger a recursive call
* to luaRedisGenericCommand(), which normally should never happen.
* To make this function reentrant is futile and makes it slower, but
* we should at least detect such a misuse, and abort. */
if (inuse) {
char *recursion_warning = "luaRedisGenericCommand() recursive call detected. "
"Are you doing funny stuff with Lua debug hooks?";
serverLog(LL_WARNING, "%s", recursion_warning);
luaPushError(lua, recursion_warning);
return 1;
}
inuse++;
/* Log the command if debugging is active. */
if (ldbIsEnabled()) {
sds cmdlog = sdsnew("<command>");
for (j = 0; j < c->argc; j++) {
if (j == 10) {
cmdlog = sdscatprintf(cmdlog, " ... (%d more)", c->argc - j - 1);
break;
} else {
cmdlog = sdscatlen(cmdlog, " ", 1);
cmdlog = sdscatsds(cmdlog, c->argv[j]->ptr);
}
}
ldbLog(cmdlog);
}
scriptCall(rctx, &err);
if (err) {
luaPushError(lua, err);
sdsfree(err);
/* push a field indicate to ignore updating the stats on this error
* because it was already updated when executing the command. */
lua_pushstring(lua, "ignore_error_stats_update");
lua_pushboolean(lua, 1);
lua_settable(lua, -3);
goto cleanup;
}
/* Convert the result of the command into a suitable Lua type.
* The first thing we need is to create a single string from the client
* output buffers. */
if (listLength(c->reply) == 0 && (size_t)c->bufpos < c->buf_usable_size) {
/* This is a fast path for the common case of a reply inside the
* client static buffer. Don't create an SDS string but just use
* the client buffer directly. */
c->buf[c->bufpos] = '\0';
reply = c->buf;
c->bufpos = 0;
} else {
reply = sdsnewlen(c->buf, c->bufpos);
c->bufpos = 0;
while (listLength(c->reply)) {
clientReplyBlock *o = listNodeValue(listFirst(c->reply));
reply = sdscatlen(reply, o->buf, o->used);
listDelNode(c->reply, listFirst(c->reply));
}
}
if (raise_error && reply[0] != '-') raise_error = 0;
redisProtocolToLuaType(lua, reply);
/* If the debugger is active, log the reply from the server. */
if (ldbIsEnabled()) ldbLogRespReply(reply);
if (reply != c->buf) sdsfree(reply);
c->reply_bytes = 0;
cleanup:
/* Clean up. Command code may have changed argv/argc so we use the
* argv/argc of the client instead of the local variables. */
freeLuaRedisArgv(c->argv, c->argc, c->argv_len);
c->argc = c->argv_len = 0;
c->user = NULL;
c->argv = NULL;
resetClient(c);
inuse--;
if (raise_error) {
/* If we are here we should have an error in the stack, in the
* form of a table with an "err" field. Extract the string to
* return the plain error. */
return luaError(lua);
}
return 1;
}
/* Our implementation to lua pcall.
* We need this implementation for backward
* comparability with older Redis OSS versions.
*
* On Redis OSS 7, the error object is a table,
* compare to older version where the error
* object is a string. To keep backward
* comparability we catch the table object
* and just return the error message. */
static int luaRedisPcall(lua_State *lua) {
int argc = lua_gettop(lua);
lua_pushboolean(lua, 1); /* result place holder */
lua_insert(lua, 1);
if (lua_pcall(lua, argc - 1, LUA_MULTRET, 0)) {
/* Error */
lua_remove(lua, 1); /* remove the result place holder, now we have room for at least one element */
if (lua_istable(lua, -1)) {
lua_getfield(lua, -1, "err");
if (lua_isstring(lua, -1)) {
lua_replace(lua, -2); /* replace the error message with the table */
}
}
lua_pushboolean(lua, 0); /* push result */
lua_insert(lua, 1);
}
return lua_gettop(lua);
}