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2389 lines (2145 loc) · 84.7 KB
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/*
* Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
* 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 "server.h"
#include "sha1.h"
#include "rand.h"
#include "cluster.h"
#include <lua.h>
#include <lauxlib.h>
#include <lualib.h>
#include <ctype.h>
#include <math.h>
char *redisProtocolToLuaType_Int(lua_State *lua, char *reply);
char *redisProtocolToLuaType_Bulk(lua_State *lua, char *reply);
char *redisProtocolToLuaType_Status(lua_State *lua, char *reply);
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 ldbInit(void);
void ldbDisable(client *c);
void ldbEnable(client *c);
void evalGenericCommandWithDebugging(client *c, int evalsha);
void luaLdbLineHook(lua_State *lua, lua_Debug *ar);
void ldbLog(sds entry);
void ldbLogRedisReply(char *reply);
sds ldbCatStackValue(sds s, lua_State *lua, int idx);
/* Debugger shared state is stored inside this global structure. */
#define LDB_BREAKPOINTS_MAX 64 /* Max number of breakpoints. */
#define LDB_MAX_LEN_DEFAULT 256 /* Default len limit for replies / var dumps. */
struct ldbState {
int fd; /* Socket of the debugging client. */
int active; /* Are we debugging EVAL right now? */
int forked; /* Is this a fork()ed debugging session? */
list *logs; /* List of messages to send to the client. */
list *traces; /* Messages about Redis commands executed since last stop.*/
list *children; /* All forked debugging sessions pids. */
int bp[LDB_BREAKPOINTS_MAX]; /* An array of breakpoints line numbers. */
int bpcount; /* Number of valid entries inside bp. */
int step; /* Stop at next line ragardless of breakpoints. */
int luabp; /* Stop at next line because redis.breakpoint() was called. */
sds *src; /* Lua script source code split by line. */
int lines; /* Number of lines in 'src'. */
int currentline; /* Current line number. */
sds cbuf; /* Debugger client command buffer. */
size_t maxlen; /* Max var dump / reply length. */
int maxlen_hint_sent; /* Did we already hint about "set maxlen"? */
} ldb;
/* ---------------------------------------------------------------------------
* Utility functions.
* ------------------------------------------------------------------------- */
/* Perform the SHA1 of the input string. We use this both for hashing 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 sha1hex(char *digest, char *script, size_t len) {
SHA1_CTX ctx;
unsigned char hash[20];
char *cset = "0123456789abcdef";
int j;
SHA1Init(&ctx);
SHA1Update(&ctx,(unsigned char*)script,len);
SHA1Final(hash,&ctx);
for (j = 0; j < 20; j++) {
digest[j*2] = cset[((hash[j]&0xF0)>>4)];
digest[j*2+1] = cset[(hash[j]&0xF)];
}
digest[40] = '\0';
}
/* ---------------------------------------------------------------------------
* Redis reply to Lua type conversion functions.
* ------------------------------------------------------------------------- */
/* 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
* clients, it is trivial to implement the redis() lua function.
*
* Basically we take the arguments, execute the Redis 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 Redis 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 Redis directly. This allows us to go faster.
*
* Errors are returned as a table with a single 'err' field set to the
* error string.
*/
char *redisProtocolToLuaType(lua_State *lua, char* reply) {
char *p = reply;
switch(*p) {
case ':': p = redisProtocolToLuaType_Int(lua,reply); break;
case '$': p = redisProtocolToLuaType_Bulk(lua,reply); break;
case '+': p = redisProtocolToLuaType_Status(lua,reply); break;
case '-': p = redisProtocolToLuaType_Error(lua,reply); break;
case '*': p = redisProtocolToLuaType_MultiBulk(lua,reply); break;
}
return p;
}
char *redisProtocolToLuaType_Int(lua_State *lua, char *reply) {
char *p = strchr(reply+1,'\r');
long long value;
string2ll(reply+1,p-reply-1,&value);
lua_pushnumber(lua,(lua_Number)value);
return p+2;
}
char *redisProtocolToLuaType_Bulk(lua_State *lua, char *reply) {
char *p = strchr(reply+1,'\r');
long long bulklen;
string2ll(reply+1,p-reply-1,&bulklen);
if (bulklen == -1) {
lua_pushboolean(lua,0);
return p+2;
} else {
lua_pushlstring(lua,p+2,bulklen);
return p+2+bulklen+2;
}
}
char *redisProtocolToLuaType_Status(lua_State *lua, char *reply) {
char *p = strchr(reply+1,'\r');
lua_newtable(lua);
lua_pushstring(lua,"ok");
lua_pushlstring(lua,reply+1,p-reply-1);
lua_settable(lua,-3);
return p+2;
}
char *redisProtocolToLuaType_Error(lua_State *lua, char *reply) {
char *p = strchr(reply+1,'\r');
lua_newtable(lua);
lua_pushstring(lua,"err");
lua_pushlstring(lua,reply+1,p-reply-1);
lua_settable(lua,-3);
return p+2;
}
char *redisProtocolToLuaType_MultiBulk(lua_State *lua, char *reply) {
char *p = strchr(reply+1,'\r');
long long mbulklen;
int j = 0;
string2ll(reply+1,p-reply-1,&mbulklen);
p += 2;
if (mbulklen == -1) {
lua_pushboolean(lua,0);
return p;
}
lua_newtable(lua);
for (j = 0; j < mbulklen; j++) {
lua_pushnumber(lua,j+1);
p = redisProtocolToLuaType(lua,p);
lua_settable(lua,-3);
}
return p;
}
/* This function is used in order to push an error on the Lua stack in the
* format used by redis.pcall to return errors, which is a lua table
* with a single "err" field set to the error string. 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. */
void luaPushError(lua_State *lua, char *error) {
lua_Debug dbg;
/* If debugging is active and in step mode, log errors resulting from
* Redis commands. */
if (ldb.active && ldb.step) {
ldbLog(sdscatprintf(sdsempty(),"<error> %s",error));
}
lua_newtable(lua);
lua_pushstring(lua,"err");
/* Attempt to figure out where this function was called, if possible */
if(lua_getstack(lua, 1, &dbg) && lua_getinfo(lua, "nSl", &dbg)) {
sds msg = sdscatprintf(sdsempty(), "%s: %d: %s",
dbg.source, dbg.currentline, error);
lua_pushstring(lua, msg);
sdsfree(msg);
} else {
lua_pushstring(lua, error);
}
lua_settable(lua,-3);
}
/* In case the error set into the Lua stack by luaPushError() was generated
* by the non-error-trapping version of redis.pcall(), which is redis.call(),
* this function will raise the Lua error so that the execution of the
* script will be halted. */
int luaRaiseError(lua_State *lua) {
lua_pushstring(lua,"err");
lua_gettable(lua,-2);
return lua_error(lua);
}
/* 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) */
}
/* ---------------------------------------------------------------------------
* Lua reply to Redis reply conversion functions.
* ------------------------------------------------------------------------- */
void luaReplyToRedisReply(client *c, lua_State *lua) {
int t = lua_type(lua,-1);
switch(t) {
case LUA_TSTRING:
addReplyBulkCBuffer(c,(char*)lua_tostring(lua,-1),lua_strlen(lua,-1));
break;
case LUA_TBOOLEAN:
addReply(c,lua_toboolean(lua,-1) ? shared.cone : shared.nullbulk);
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. */
lua_pushstring(lua,"err");
lua_gettable(lua,-2);
t = lua_type(lua,-1);
if (t == LUA_TSTRING) {
sds err = sdsnew(lua_tostring(lua,-1));
sdsmapchars(err,"\r\n"," ",2);
addReplySds(c,sdscatprintf(sdsempty(),"-%s\r\n",err));
sdsfree(err);
lua_pop(lua,2);
return;
}
lua_pop(lua,1);
lua_pushstring(lua,"ok");
lua_gettable(lua,-2);
t = lua_type(lua,-1);
if (t == LUA_TSTRING) {
sds ok = sdsnew(lua_tostring(lua,-1));
sdsmapchars(ok,"\r\n"," ",2);
addReplySds(c,sdscatprintf(sdsempty(),"+%s\r\n",ok));
sdsfree(ok);
lua_pop(lua,1);
} else {
void *replylen = addDeferredMultiBulkLength(c);
int j = 1, mbulklen = 0;
lua_pop(lua,1); /* Discard the 'ok' field value we popped */
while(1) {
lua_pushnumber(lua,j++);
lua_gettable(lua,-2);
t = lua_type(lua,-1);
if (t == LUA_TNIL) {
lua_pop(lua,1);
break;
}
luaReplyToRedisReply(c, lua);
mbulklen++;
}
setDeferredMultiBulkLength(c,replylen,mbulklen);
}
break;
default:
addReply(c,shared.nullbulk);
}
lua_pop(lua,1);
}
/* ---------------------------------------------------------------------------
* Lua redis.* functions implementations.
* ------------------------------------------------------------------------- */
#define LUA_CMD_OBJCACHE_SIZE 32
#define LUA_CMD_OBJCACHE_MAX_LEN 64
int luaRedisGenericCommand(lua_State *lua, int raise_error) {
int j, argc = lua_gettop(lua);
struct redisCommand *cmd;
client *c = server.lua_client;
sds reply;
/* Cached across calls. */
static robj **argv = NULL;
static int argv_size = 0;
static robj *cached_objects[LUA_CMD_OBJCACHE_SIZE];
static size_t cached_objects_len[LUA_CMD_OBJCACHE_SIZE];
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++;
/* Require at least one argument */
if (argc == 0) {
luaPushError(lua,
"Please specify at least one argument for redis.call()");
inuse--;
return raise_error ? luaRaiseError(lua) : 1;
}
/* Build the arguments vector */
if (argv_size < argc) {
argv = zrealloc(argv,sizeof(robj*)*argc);
argv_size = argc;
}
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);
obj_len = snprintf(dbuf,sizeof(dbuf),"%.17g",(double)num);
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 && cached_objects[j] &&
cached_objects_len[j] >= obj_len)
{
sds s = cached_objects[j]->ptr;
argv[j] = cached_objects[j];
cached_objects[j] = NULL;
memcpy(s,obj_s,obj_len+1);
sdssetlen(s, obj_len);
} else {
argv[j] = createStringObject(obj_s, obj_len);
}
}
/* 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) {
j--;
while (j >= 0) {
decrRefCount(argv[j]);
j--;
}
luaPushError(lua,
"Lua redis() command arguments must be strings or integers");
inuse--;
return raise_error ? luaRaiseError(lua) : 1;
}
/* Setup our fake client for command execution */
c->argv = argv;
c->argc = argc;
/* Log the command if debugging is active. */
if (ldb.active && ldb.step) {
sds cmdlog = sdsnew("<redis>");
for (j = 0; j < c->argc; j++) {
if (j == 10) {
cmdlog = sdscatprintf(cmdlog," ... (%d more)",
c->argc-j-1);
} else {
cmdlog = sdscatlen(cmdlog," ",1);
cmdlog = sdscatsds(cmdlog,c->argv[j]->ptr);
}
}
ldbLog(cmdlog);
}
/* Command lookup */
cmd = lookupCommand(argv[0]->ptr);
if (!cmd || ((cmd->arity > 0 && cmd->arity != argc) ||
(argc < -cmd->arity)))
{
if (cmd)
luaPushError(lua,
"Wrong number of args calling Redis command From Lua script");
else
luaPushError(lua,"Unknown Redis command called from Lua script");
goto cleanup;
}
c->cmd = c->lastcmd = cmd;
/* There are commands that are not allowed inside scripts. */
if (cmd->flags & CMD_NOSCRIPT) {
luaPushError(lua, "This Redis command is not allowed from scripts");
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 & CMD_WRITE) {
if (server.lua_random_dirty && !server.lua_replicate_commands) {
luaPushError(lua,
"Write commands not allowed after non deterministic commands. Call redis.replicate_commands() at the start of your script in order to switch to single commands replication mode.");
goto cleanup;
} else if (server.masterhost && server.repl_slave_ro &&
!server.loading &&
!(server.lua_caller->flags & CLIENT_MASTER))
{
luaPushError(lua, shared.roslaveerr->ptr);
goto cleanup;
} else if (server.stop_writes_on_bgsave_err &&
server.saveparamslen > 0 &&
server.lastbgsave_status == C_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 & CMD_DENYOOM))
{
if (freeMemoryIfNeeded() == C_ERR) {
luaPushError(lua, shared.oomerr->ptr);
goto cleanup;
}
}
if (cmd->flags & CMD_RANDOM) server.lua_random_dirty = 1;
if (cmd->flags & CMD_WRITE) server.lua_write_dirty = 1;
/* If this is a Redis Cluster node, we need to make sure Lua is not
* trying to access non-local keys, with the exception of commands
* received from our master or when loading the AOF back in memory. */
if (server.cluster_enabled && !server.loading &&
!(server.lua_caller->flags & CLIENT_MASTER))
{
/* Duplicate relevant flags in the lua client. */
c->flags &= ~(CLIENT_READONLY|CLIENT_ASKING);
c->flags |= server.lua_caller->flags & (CLIENT_READONLY|CLIENT_ASKING);
if (getNodeByQuery(c,c->cmd,c->argv,c->argc,NULL,NULL) !=
server.cluster->myself)
{
luaPushError(lua,
"Lua script attempted to access a non local key in a "
"cluster node");
goto cleanup;
}
}
/* If we are using single commands replication, we need to wrap what
* we propagate into a MULTI/EXEC block, so that it will be atomic like
* a Lua script in the context of AOF and slaves. */
if (server.lua_replicate_commands &&
!server.lua_multi_emitted &&
server.lua_write_dirty &&
server.lua_repl != PROPAGATE_NONE)
{
execCommandPropagateMulti(server.lua_caller);
server.lua_multi_emitted = 1;
}
/* Run the command */
int call_flags = CMD_CALL_SLOWLOG | CMD_CALL_STATS;
if (server.lua_replicate_commands) {
/* Set flags according to redis.set_repl() settings. */
if (server.lua_repl & PROPAGATE_AOF)
call_flags |= CMD_CALL_PROPAGATE_AOF;
if (server.lua_repl & PROPAGATE_REPL)
call_flags |= CMD_CALL_PROPAGATE_REPL;
}
call(c,call_flags);
/* 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
* output buffers. */
if (listLength(c->reply) == 0 && c->bufpos < PROTO_REPLY_CHUNK_BYTES) {
/* 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)) {
sds o = listNodeValue(listFirst(c->reply));
reply = sdscatsds(reply,o);
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 Redis. */
if (ldb.active && ldb.step)
ldbLogRedisReply(reply);
/* Sort the output array if needed, assuming it is a non-null multi bulk
* reply as expected. */
if ((cmd->flags & CMD_SORT_FOR_SCRIPT) &&
(server.lua_replicate_commands == 0) &&
(reply[0] == '*' && reply[1] != '-')) {
luaSortArray(lua);
}
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. */
for (j = 0; j < c->argc; j++) {
robj *o = c->argv[j];
/* Try to cache the object in the 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 (cached_objects[j]) decrRefCount(cached_objects[j]);
cached_objects[j] = o;
cached_objects_len[j] = sdsalloc(s);
} else {
decrRefCount(o);
}
}
if (c->argv != argv) {
zfree(c->argv);
argv = NULL;
argv_size = 0;
}
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. */
inuse--;
return luaRaiseError(lua);
}
inuse--;
return 1;
}
/* redis.call() */
int luaRedisCallCommand(lua_State *lua) {
return luaRedisGenericCommand(lua,1);
}
/* redis.pcall() */
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) {
lua_pushstring(lua, "wrong number of arguments");
return lua_error(lua);
}
s = (char*)lua_tolstring(lua,1,&len);
sha1hex(digest,s,len);
lua_pushstring(lua,digest);
return 1;
}
/* 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;
}
/* redis.error_reply() */
int luaRedisErrorReplyCommand(lua_State *lua) {
return luaRedisReturnSingleFieldTable(lua,"err");
}
/* redis.status_reply() */
int luaRedisStatusReplyCommand(lua_State *lua) {
return luaRedisReturnSingleFieldTable(lua,"ok");
}
/* redis.replicate_commands()
*
* Turn on single commands replication if the script never called
* a write command so far, and returns true. Otherwise if the script
* already started to write, returns false and stick to whole scripts
* replication, which is our default. */
int luaRedisReplicateCommandsCommand(lua_State *lua) {
if (server.lua_write_dirty) {
lua_pushboolean(lua,0);
} else {
server.lua_replicate_commands = 1;
/* When we switch to single commands replication, we can provide
* different math.random() sequences at every call, which is what
* the user normally expects. */
redisSrand48(rand());
lua_pushboolean(lua,1);
}
return 1;
}
/* redis.breakpoint()
*
* Allows to stop execution during a debuggign session from within
* the Lua code implementation, like if a breakpoint was set in the code
* immediately after the function. */
int luaRedisBreakpointCommand(lua_State *lua) {
if (ldb.active) {
ldb.luabp = 1;
lua_pushboolean(lua,1);
} else {
lua_pushboolean(lua,0);
}
return 1;
}
/* redis.debug()
*
* Log a string message into the output console.
* Can take multiple arguments that will be separated by commas.
* Nothing is returned to the caller. */
int luaRedisDebugCommand(lua_State *lua) {
if (!ldb.active) return 0;
int argc = lua_gettop(lua);
sds log = sdscatprintf(sdsempty(),"<debug> line %d: ", ldb.currentline);
while(argc--) {
log = ldbCatStackValue(log,lua,-1 - argc);
if (argc != 0) log = sdscatlen(log,", ",2);
}
ldbLog(log);
return 0;
}
/* redis.set_repl()
*
* Set the propagation of write commands executed in the context of the
* script to on/off for AOF and slaves. */
int luaRedisSetReplCommand(lua_State *lua) {
int argc = lua_gettop(lua);
int flags;
if (server.lua_replicate_commands == 0) {
lua_pushstring(lua, "You can set the replication behavior only after turning on single commands replication with redis.replicate_commands().");
return lua_error(lua);
} else if (argc != 1) {
lua_pushstring(lua, "redis.set_repl() requires two arguments.");
return lua_error(lua);
}
flags = lua_tonumber(lua,-1);
if ((flags & ~(PROPAGATE_AOF|PROPAGATE_REPL)) != 0) {
lua_pushstring(lua, "Invalid replication flags. Use REPL_AOF, REPL_SLAVE, REPL_ALL or REPL_NONE.");
return lua_error(lua);
}
server.lua_repl = flags;
return 0;
}
/* redis.log() */
int luaLogCommand(lua_State *lua) {
int j, argc = lua_gettop(lua);
int level;
sds log;
if (argc < 2) {
lua_pushstring(lua, "redis.log() requires two arguments or more.");
return lua_error(lua);
} else if (!lua_isnumber(lua,-argc)) {
lua_pushstring(lua, "First argument must be a number (log level).");
return lua_error(lua);
}
level = lua_tonumber(lua,-argc);
if (level < LL_DEBUG || level > LL_WARNING) {
lua_pushstring(lua, "Invalid debug level.");
return lua_error(lua);
}
/* 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);
}
}
serverLogRaw(level,log);
sdsfree(log);
return 0;
}
/* ---------------------------------------------------------------------------
* Lua engine initialization and reset.
* ------------------------------------------------------------------------- */
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);
LUALIB_API int (luaopen_bit) (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);
luaLoadLib(lua, "bit", luaopen_bit);
#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");
lua_pushnil(lua);
lua_setglobal(lua,"dofile");
}
/* 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 dbg=debug\n";
s[j++]="local mt = {}\n";
s[j++]="setmetatable(_G, mt)\n";
s[j++]="mt.__newindex = function (t, n, v)\n";
s[j++]=" if dbg.getinfo(2) then\n";
s[j++]=" local w = dbg.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 dbg.getinfo(2) and dbg.getinfo(2, \"S\").what ~= \"C\" then\n";
s[j++]=" error(\"Script attempted to access nonexistent global variable '\"..tostring(n)..\"'\", 2)\n";
s[j++]=" end\n";
s[j++]=" return rawget(t, n)\n";
s[j++]="end\n";
s[j++]="debug = nil\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.
*
* This function is called the first time at server startup with
* the 'setup' argument set to 1.
*
* It can be called again multiple times during the lifetime of the Redis
* process, with 'setup' set to 0, and following a scriptingRelease() call,
* in order to reset the Lua scripting environment.
*
* However it is simpler to just call scriptingReset() that does just that. */
void scriptingInit(int setup) {
lua_State *lua = lua_open();
if (setup) {
server.lua_client = NULL;
server.lua_caller = NULL;
server.lua_timedout = 0;
server.lua_always_replicate_commands = 0; /* Only DEBUG can change it.*/
server.lua_time_limit = LUA_SCRIPT_TIME_LIMIT;
ldbInit();
}
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
* as EVAL, so we need to remember the associated script. */
server.lua_scripts = dictCreate(&shaScriptObjectDictType,NULL);
/* Register the redis commands table and fields */
lua_newtable(lua);
/* redis.call */
lua_pushstring(lua,"call");
lua_pushcfunction(lua,luaRedisCallCommand);
lua_settable(lua,-3);
/* redis.pcall */
lua_pushstring(lua,"pcall");
lua_pushcfunction(lua,luaRedisPCallCommand);
lua_settable(lua,-3);
/* redis.log and log levels. */
lua_pushstring(lua,"log");
lua_pushcfunction(lua,luaLogCommand);
lua_settable(lua,-3);
lua_pushstring(lua,"LOG_DEBUG");
lua_pushnumber(lua,LL_DEBUG);
lua_settable(lua,-3);
lua_pushstring(lua,"LOG_VERBOSE");
lua_pushnumber(lua,LL_VERBOSE);
lua_settable(lua,-3);
lua_pushstring(lua,"LOG_NOTICE");
lua_pushnumber(lua,LL_NOTICE);
lua_settable(lua,-3);
lua_pushstring(lua,"LOG_WARNING");
lua_pushnumber(lua,LL_WARNING);
lua_settable(lua,-3);
/* redis.sha1hex */
lua_pushstring(lua, "sha1hex");
lua_pushcfunction(lua, luaRedisSha1hexCommand);
lua_settable(lua, -3);
/* redis.error_reply and redis.status_reply */
lua_pushstring(lua, "error_reply");
lua_pushcfunction(lua, luaRedisErrorReplyCommand);
lua_settable(lua, -3);
lua_pushstring(lua, "status_reply");
lua_pushcfunction(lua, luaRedisStatusReplyCommand);
lua_settable(lua, -3);
/* redis.replicate_commands */
lua_pushstring(lua, "replicate_commands");
lua_pushcfunction(lua, luaRedisReplicateCommandsCommand);
lua_settable(lua, -3);
/* redis.set_repl and associated flags. */
lua_pushstring(lua,"set_repl");
lua_pushcfunction(lua,luaRedisSetReplCommand);
lua_settable(lua,-3);
lua_pushstring(lua,"REPL_NONE");
lua_pushnumber(lua,PROPAGATE_NONE);
lua_settable(lua,-3);
lua_pushstring(lua,"REPL_AOF");
lua_pushnumber(lua,PROPAGATE_AOF);
lua_settable(lua,-3);
lua_pushstring(lua,"REPL_SLAVE");
lua_pushnumber(lua,PROPAGATE_REPL);
lua_settable(lua,-3);
lua_pushstring(lua,"REPL_ALL");
lua_pushnumber(lua,PROPAGATE_AOF|PROPAGATE_REPL);
lua_settable(lua,-3);
/* redis.breakpoint */
lua_pushstring(lua,"breakpoint");
lua_pushcfunction(lua,luaRedisBreakpointCommand);
lua_settable(lua,-3);
/* redis.debug */
lua_pushstring(lua,"debug");
lua_pushcfunction(lua,luaRedisDebugCommand);
lua_settable(lua,-3);
/* Finally set the table as 'redis' global var. */
lua_setglobal(lua,"redis");