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eval.c
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1685 lines (1530 loc) · 60.5 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 "monotonic.h"
#include "resp_parser.h"
#include "script_lua.h"
#include <lua.h>
#include <lauxlib.h>
#include <lualib.h>
#include <ctype.h>
#include <math.h>
void ldbInit(void);
void ldbDisable(client *c);
void ldbEnable(client *c);
void evalGenericCommandWithDebugging(client *c, int evalsha);
sds ldbCatStackValue(sds s, lua_State *lua, int idx);
static void dictLuaScriptDestructor(dict *d, void *val) {
UNUSED(d);
if (val == NULL) return; /* Lazy freeing will set value to NULL. */
decrRefCount(((luaScript*)val)->body);
zfree(val);
}
static uint64_t dictStrCaseHash(const void *key) {
return dictGenCaseHashFunction((unsigned char*)key, strlen((char*)key));
}
/* server.lua_scripts sha (as sds string) -> scripts (as luaScript) cache. */
dictType shaScriptObjectDictType = {
dictStrCaseHash, /* hash function */
NULL, /* key dup */
NULL, /* val dup */
dictSdsKeyCaseCompare, /* key compare */
dictSdsDestructor, /* key destructor */
dictLuaScriptDestructor, /* val destructor */
NULL /* allow to expand */
};
/* Lua context */
struct luaCtx {
lua_State *lua; /* The Lua interpreter. We use just one for all clients */
client *lua_client; /* The "fake client" to query Redis from Lua */
dict *lua_scripts; /* A dictionary of SHA1 -> Lua scripts */
unsigned long long lua_scripts_mem; /* Cached scripts' memory + oh */
} lctx;
/* 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 {
connection *conn; /* Connection 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 regardless 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.breakpoint()
*
* Allows to stop execution during a debugging 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.replicate_commands()
*
* DEPRECATED: Now do nothing and always return true.
* 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) {
lua_pushboolean(lua,1);
return 1;
}
/* 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) {
lctx.lua_client = NULL;
server.script_caller = NULL;
server.script_disable_deny_script = 0;
ldbInit();
}
/* 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. */
lctx.lua_scripts = dictCreate(&shaScriptObjectDictType);
lctx.lua_scripts_mem = 0;
luaRegisterRedisAPI(lua);
/* register debug commands */
lua_getglobal(lua,"redis");
/* 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);
/* redis.replicate_commands */
lua_pushstring(lua, "replicate_commands");
lua_pushcfunction(lua, luaRedisReplicateCommandsCommand);
lua_settable(lua, -3);
lua_setglobal(lua,"redis");
/* Add a helper function we use for pcall error reporting.
* Note that when the error is in the C function we want to report the
* information about the caller, that's what makes sense from the point
* of view of the user debugging a script. */
{
char *errh_func = "local dbg = debug\n"
"debug = nil\n"
"function __redis__err__handler(err)\n"
" local i = dbg.getinfo(2,'nSl')\n"
" if i and i.what == 'C' then\n"
" i = dbg.getinfo(3,'nSl')\n"
" end\n"
" if type(err) ~= 'table' then\n"
" err = {err='ERR ' .. tostring(err)}"
" end"
" if i then\n"
" err['source'] = i.source\n"
" err['line'] = i.currentline\n"
" end"
" return err\n"
"end\n";
luaL_loadbuffer(lua,errh_func,strlen(errh_func),"@err_handler_def");
lua_pcall(lua,0,0,0);
}
/* Create the (non connected) client that we use to execute Redis commands
* inside the Lua interpreter.
* Note: there is no need to create it again when this function is called
* by scriptingReset(). */
if (lctx.lua_client == NULL) {
lctx.lua_client = createClient(NULL);
lctx.lua_client->flags |= CLIENT_SCRIPT;
/* We do not want to allow blocking commands inside Lua */
lctx.lua_client->flags |= CLIENT_DENY_BLOCKING;
}
/* Lock the global table from any changes */
lua_pushvalue(lua, LUA_GLOBALSINDEX);
luaSetErrorMetatable(lua);
/* Recursively lock all tables that can be reached from the global table */
luaSetTableProtectionRecursively(lua);
lua_pop(lua, 1);
lctx.lua = lua;
}
/* Release resources related to Lua scripting.
* This function is used in order to reset the scripting environment. */
void scriptingRelease(int async) {
if (async)
freeLuaScriptsAsync(lctx.lua_scripts);
else
dictRelease(lctx.lua_scripts);
lctx.lua_scripts_mem = 0;
lua_close(lctx.lua);
}
void scriptingReset(int async) {
scriptingRelease(async);
scriptingInit(0);
}
/* ---------------------------------------------------------------------------
* EVAL and SCRIPT commands implementation
* ------------------------------------------------------------------------- */
static void evalCalcFunctionName(int evalsha, sds script, char *out_funcname) {
/* We obtain the script SHA1, then check if this function is already
* defined into the Lua state */
out_funcname[0] = 'f';
out_funcname[1] = '_';
if (!evalsha) {
/* Hash the code if this is an EVAL call */
sha1hex(out_funcname+2,script,sdslen(script));
} else {
/* We already have the SHA if it is an EVALSHA */
int j;
char *sha = script;
/* Convert to lowercase. We don't use tolower since the function
* managed to always show up in the profiler output consuming
* a non trivial amount of time. */
for (j = 0; j < 40; j++)
out_funcname[j+2] = (sha[j] >= 'A' && sha[j] <= 'Z') ?
sha[j]+('a'-'A') : sha[j];
out_funcname[42] = '\0';
}
}
/* Helper function to try and extract shebang flags from the script body.
* If no shebang is found, return with success and COMPAT mode flag.
* The err arg is optional, can be used to get a detailed error string.
* The out_shebang_len arg is optional, can be used to trim the shebang from the script.
* Returns C_OK on success, and C_ERR on error. */
int evalExtractShebangFlags(sds body, uint64_t *out_flags, ssize_t *out_shebang_len, sds *err) {
ssize_t shebang_len = 0;
uint64_t script_flags = SCRIPT_FLAG_EVAL_COMPAT_MODE;
if (!strncmp(body, "#!", 2)) {
int numparts,j;
char *shebang_end = strchr(body, '\n');
if (shebang_end == NULL) {
if (err)
*err = sdsnew("Invalid script shebang");
return C_ERR;
}
shebang_len = shebang_end - body;
sds shebang = sdsnewlen(body, shebang_len);
sds *parts = sdssplitargs(shebang, &numparts);
sdsfree(shebang);
if (!parts || numparts == 0) {
if (err)
*err = sdsnew("Invalid engine in script shebang");
sdsfreesplitres(parts, numparts);
return C_ERR;
}
/* Verify lua interpreter was specified */
if (strcmp(parts[0], "#!lua")) {
if (err)
*err = sdscatfmt(sdsempty(), "Unexpected engine in script shebang: %s", parts[0]);
sdsfreesplitres(parts, numparts);
return C_ERR;
}
script_flags &= ~SCRIPT_FLAG_EVAL_COMPAT_MODE;
for (j = 1; j < numparts; j++) {
if (!strncmp(parts[j], "flags=", 6)) {
sdsrange(parts[j], 6, -1);
int numflags, jj;
sds *flags = sdssplitlen(parts[j], sdslen(parts[j]), ",", 1, &numflags);
for (jj = 0; jj < numflags; jj++) {
scriptFlag *sf;
for (sf = scripts_flags_def; sf->flag; sf++) {
if (!strcmp(flags[jj], sf->str)) break;
}
if (!sf->flag) {
if (err)
*err = sdscatfmt(sdsempty(), "Unexpected flag in script shebang: %s", flags[jj]);
sdsfreesplitres(flags, numflags);
sdsfreesplitres(parts, numparts);
return C_ERR;
}
script_flags |= sf->flag;
}
sdsfreesplitres(flags, numflags);
} else {
/* We only support function flags options for lua scripts */
if (err)
*err = sdscatfmt(sdsempty(), "Unknown lua shebang option: %s", parts[j]);
sdsfreesplitres(parts, numparts);
return C_ERR;
}
}
sdsfreesplitres(parts, numparts);
}
if (out_shebang_len)
*out_shebang_len = shebang_len;
*out_flags = script_flags;
return C_OK;
}
/* Try to extract command flags if we can, returns the modified flags.
* Note that it does not guarantee the command arguments are right. */
uint64_t evalGetCommandFlags(client *c, uint64_t cmd_flags) {
char funcname[43];
int evalsha = c->cmd->proc == evalShaCommand || c->cmd->proc == evalShaRoCommand;
if (evalsha && sdslen(c->argv[1]->ptr) != 40)
return cmd_flags;
uint64_t script_flags;
evalCalcFunctionName(evalsha, c->argv[1]->ptr, funcname);
char *lua_cur_script = funcname + 2;
c->cur_script = dictFind(lctx.lua_scripts, lua_cur_script);
if (!c->cur_script) {
if (evalsha)
return cmd_flags;
if (evalExtractShebangFlags(c->argv[1]->ptr, &script_flags, NULL, NULL) == C_ERR)
return cmd_flags;
} else {
luaScript *l = dictGetVal(c->cur_script);
script_flags = l->flags;
}
if (script_flags & SCRIPT_FLAG_EVAL_COMPAT_MODE)
return cmd_flags;
return scriptFlagsToCmdFlags(cmd_flags, script_flags);
}
/* Define a Lua function with the specified body.
* The function name will be generated in the following form:
*
* f_<hex sha1 sum>
*
* The function increments the reference count of the 'body' object as a
* side effect of a successful call.
*
* On success a pointer to an SDS string representing the function SHA1 of the
* just added function is returned (and will be valid until the next call
* to scriptingReset() function), otherwise NULL is returned.
*
* The function handles the fact of being called with a script that already
* exists, and in such a case, it behaves like in the success case.
*
* If 'c' is not NULL, on error the client is informed with an appropriate
* error describing the nature of the problem and the Lua interpreter error. */
sds luaCreateFunction(client *c, robj *body) {
char funcname[43];
dictEntry *de;
uint64_t script_flags;
funcname[0] = 'f';
funcname[1] = '_';
sha1hex(funcname+2,body->ptr,sdslen(body->ptr));
if ((de = dictFind(lctx.lua_scripts,funcname+2)) != NULL) {
return dictGetKey(de);
}
/* Handle shebang header in script code */
ssize_t shebang_len = 0;
sds err = NULL;
if (evalExtractShebangFlags(body->ptr, &script_flags, &shebang_len, &err) == C_ERR) {
addReplyErrorSds(c, err);
return NULL;
}
/* Note that in case of a shebang line we skip it but keep the line feed to conserve the user's line numbers */
if (luaL_loadbuffer(lctx.lua,(char*)body->ptr + shebang_len,sdslen(body->ptr) - shebang_len,"@user_script")) {
if (c != NULL) {
addReplyErrorFormat(c,
"Error compiling script (new function): %s",
lua_tostring(lctx.lua,-1));
}
lua_pop(lctx.lua,1);
return NULL;
}
serverAssert(lua_isfunction(lctx.lua, -1));
lua_setfield(lctx.lua, LUA_REGISTRYINDEX, 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. */
luaScript *l = zcalloc(sizeof(luaScript));
l->body = body;
l->flags = script_flags;
sds sha = sdsnewlen(funcname+2,40);
int retval = dictAdd(lctx.lua_scripts,sha,l);
serverAssertWithInfo(c ? c : lctx.lua_client,NULL,retval == DICT_OK);
lctx.lua_scripts_mem += sdsZmallocSize(sha) + getStringObjectSdsUsedMemory(body);
incrRefCount(body);
return sha;
}
void prepareLuaClient(void) {
/* Select the right DB in the context of the Lua client */
selectDb(lctx.lua_client,server.script_caller->db->id);
lctx.lua_client->resp = 2; /* Default is RESP2, scripts can change it. */
/* If we are in MULTI context, flag Lua client as CLIENT_MULTI. */
if (server.script_caller->flags & CLIENT_MULTI) {
lctx.lua_client->flags |= CLIENT_MULTI;
}
}
void resetLuaClient(void) {
/* After the script done, remove the MULTI state. */
lctx.lua_client->flags &= ~CLIENT_MULTI;
}
void evalGenericCommand(client *c, int evalsha) {
lua_State *lua = lctx.lua;
char funcname[43];
long long numkeys;
/* Get the number of arguments that are keys */
if (getLongLongFromObjectOrReply(c,c->argv[2],&numkeys,NULL) != C_OK)
return;
if (numkeys > (c->argc - 3)) {
addReplyError(c,"Number of keys can't be greater than number of args");
return;
} else if (numkeys < 0) {
addReplyError(c,"Number of keys can't be negative");
return;
}
if (c->cur_script) {
funcname[0] = 'f', funcname[1] = '_';
memcpy(funcname+2, dictGetKey(c->cur_script), 40);
funcname[42] = '\0';
} else
evalCalcFunctionName(evalsha, c->argv[1]->ptr, funcname);
/* Push the pcall error handler function on the stack. */
lua_getglobal(lua, "__redis__err__handler");
/* Try to lookup the Lua function */
lua_getfield(lua, LUA_REGISTRYINDEX, funcname);
if (lua_isnil(lua,-1)) {
lua_pop(lua,1); /* remove the nil from the stack */
/* Function not defined... let's define it if we have the
* body of the function. If this is an EVALSHA call we can just
* return an error. */
if (evalsha) {
lua_pop(lua,1); /* remove the error handler from the stack. */
addReplyErrorObject(c, shared.noscripterr);
return;
}
if (luaCreateFunction(c,c->argv[1]) == NULL) {
lua_pop(lua,1); /* remove the error handler from the stack. */
/* The error is sent to the client by luaCreateFunction()
* itself when it returns NULL. */
return;
}
/* Now the following is guaranteed to return non nil */
lua_getfield(lua, LUA_REGISTRYINDEX, funcname);
serverAssert(!lua_isnil(lua,-1));
}
char *lua_cur_script = funcname + 2;
dictEntry *de = c->cur_script;
if (!de)
de = dictFind(lctx.lua_scripts, lua_cur_script);
luaScript *l = dictGetVal(de);
int ro = c->cmd->proc == evalRoCommand || c->cmd->proc == evalShaRoCommand;
scriptRunCtx rctx;
if (scriptPrepareForRun(&rctx, lctx.lua_client, c, lua_cur_script, l->flags, ro) != C_OK) {
lua_pop(lua,2); /* Remove the function and error handler. */
return;
}
rctx.flags |= SCRIPT_EVAL_MODE; /* mark the current run as EVAL (as opposed to FCALL) so we'll
get appropriate error messages and logs */
luaCallFunction(&rctx, lua, c->argv+3, numkeys, c->argv+3+numkeys, c->argc-3-numkeys, ldb.active);
lua_pop(lua,1); /* Remove the error handler. */
scriptResetRun(&rctx);
}
void evalCommand(client *c) {
/* Explicitly feed monitor here so that lua commands appear after their
* script command. */
replicationFeedMonitors(c,server.monitors,c->db->id,c->argv,c->argc);
if (!(c->flags & CLIENT_LUA_DEBUG))
evalGenericCommand(c,0);
else
evalGenericCommandWithDebugging(c,0);
}
void evalRoCommand(client *c) {
evalCommand(c);
}
void evalShaCommand(client *c) {
/* Explicitly feed monitor here so that lua commands appear after their
* script command. */
replicationFeedMonitors(c,server.monitors,c->db->id,c->argv,c->argc);
if (sdslen(c->argv[1]->ptr) != 40) {
/* We know that a match is not possible if the provided SHA is
* not the right length. So we return an error ASAP, this way
* evalGenericCommand() can be implemented without string length
* sanity check */
addReplyErrorObject(c, shared.noscripterr);
return;
}
if (!(c->flags & CLIENT_LUA_DEBUG))
evalGenericCommand(c,1);
else {
addReplyError(c,"Please use EVAL instead of EVALSHA for debugging");
return;
}
}
void evalShaRoCommand(client *c) {
evalShaCommand(c);
}
void scriptCommand(client *c) {
if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"help")) {
const char *help[] = {
"DEBUG (YES|SYNC|NO)",
" Set the debug mode for subsequent scripts executed.",
"EXISTS <sha1> [<sha1> ...]",
" Return information about the existence of the scripts in the script cache.",
"FLUSH [ASYNC|SYNC]",
" Flush the Lua scripts cache. Very dangerous on replicas.",
" When called without the optional mode argument, the behavior is determined by the",
" lazyfree-lazy-user-flush configuration directive. Valid modes are:",
" * ASYNC: Asynchronously flush the scripts cache.",
" * SYNC: Synchronously flush the scripts cache.",
"KILL",
" Kill the currently executing Lua script.",
"LOAD <script>",
" Load a script into the scripts cache without executing it.",
NULL
};
addReplyHelp(c, help);
} else if (c->argc >= 2 && !strcasecmp(c->argv[1]->ptr,"flush")) {
int async = 0;
if (c->argc == 3 && !strcasecmp(c->argv[2]->ptr,"sync")) {
async = 0;
} else if (c->argc == 3 && !strcasecmp(c->argv[2]->ptr,"async")) {
async = 1;
} else if (c->argc == 2) {
async = server.lazyfree_lazy_user_flush ? 1 : 0;
} else {
addReplyError(c,"SCRIPT FLUSH only support SYNC|ASYNC option");
return;
}
scriptingReset(async);
addReply(c,shared.ok);
} else if (c->argc >= 2 && !strcasecmp(c->argv[1]->ptr,"exists")) {
int j;
addReplyArrayLen(c, c->argc-2);
for (j = 2; j < c->argc; j++) {
if (dictFind(lctx.lua_scripts,c->argv[j]->ptr))
addReply(c,shared.cone);
else
addReply(c,shared.czero);
}
} else if (c->argc == 3 && !strcasecmp(c->argv[1]->ptr,"load")) {
sds sha = luaCreateFunction(c,c->argv[2]);
if (sha == NULL) return; /* The error was sent by luaCreateFunction(). */
addReplyBulkCBuffer(c,sha,40);
} else if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"kill")) {
scriptKill(c, 1);
} else if (c->argc == 3 && !strcasecmp(c->argv[1]->ptr,"debug")) {
if (clientHasPendingReplies(c)) {
addReplyError(c,"SCRIPT DEBUG must be called outside a pipeline");
return;
}
if (!strcasecmp(c->argv[2]->ptr,"no")) {
ldbDisable(c);
addReply(c,shared.ok);
} else if (!strcasecmp(c->argv[2]->ptr,"yes")) {
ldbEnable(c);
addReply(c,shared.ok);
} else if (!strcasecmp(c->argv[2]->ptr,"sync")) {
ldbEnable(c);
addReply(c,shared.ok);
c->flags |= CLIENT_LUA_DEBUG_SYNC;
} else {
addReplyError(c,"Use SCRIPT DEBUG YES/SYNC/NO");
return;
}
} else {
addReplySubcommandSyntaxError(c);
}
}
unsigned long evalMemory() {
return luaMemory(lctx.lua);
}
dict* evalScriptsDict() {
return lctx.lua_scripts;
}
unsigned long evalScriptsMemory() {
return lctx.lua_scripts_mem +
dictSize(lctx.lua_scripts) * (sizeof(dictEntry) + sizeof(luaScript)) +
dictSlots(lctx.lua_scripts) * sizeof(dictEntry*);
}
/* ---------------------------------------------------------------------------
* LDB: Redis Lua debugging facilities
* ------------------------------------------------------------------------- */
/* Initialize Lua debugger data structures. */
void ldbInit(void) {
ldb.conn = NULL;
ldb.active = 0;
ldb.logs = listCreate();
listSetFreeMethod(ldb.logs,(void (*)(void*))sdsfree);
ldb.children = listCreate();
ldb.src = NULL;
ldb.lines = 0;
ldb.cbuf = sdsempty();
}
/* Remove all the pending messages in the specified list. */
void ldbFlushLog(list *log) {
listNode *ln;
while((ln = listFirst(log)) != NULL)
listDelNode(log,ln);
}
int ldbIsEnabled(){
return ldb.active && ldb.step;
}
/* Enable debug mode of Lua scripts for this client. */
void ldbEnable(client *c) {
c->flags |= CLIENT_LUA_DEBUG;
ldbFlushLog(ldb.logs);
ldb.conn = c->conn;
ldb.step = 1;
ldb.bpcount = 0;
ldb.luabp = 0;
sdsfree(ldb.cbuf);
ldb.cbuf = sdsempty();
ldb.maxlen = LDB_MAX_LEN_DEFAULT;
ldb.maxlen_hint_sent = 0;
}
/* Exit debugging mode from the POV of client. This function is not enough
* to properly shut down a client debugging session, see ldbEndSession()
* for more information. */
void ldbDisable(client *c) {
c->flags &= ~(CLIENT_LUA_DEBUG|CLIENT_LUA_DEBUG_SYNC);
}
/* Append a log entry to the specified LDB log. */
void ldbLog(sds entry) {
listAddNodeTail(ldb.logs,entry);
}
/* A version of ldbLog() which prevents producing logs greater than
* ldb.maxlen. The first time the limit is reached a hint is generated
* to inform the user that reply trimming can be disabled using the
* debugger "maxlen" command. */
void ldbLogWithMaxLen(sds entry) {
int trimmed = 0;
if (ldb.maxlen && sdslen(entry) > ldb.maxlen) {
sdsrange(entry,0,ldb.maxlen-1);
entry = sdscatlen(entry," ...",4);
trimmed = 1;
}
ldbLog(entry);
if (trimmed && ldb.maxlen_hint_sent == 0) {
ldb.maxlen_hint_sent = 1;
ldbLog(sdsnew(
"<hint> The above reply was trimmed. Use 'maxlen 0' to disable trimming."));
}
}
/* Send ldb.logs to the debugging client as a multi-bulk reply
* consisting of simple strings. Log entries which include newlines have them
* replaced with spaces. The entries sent are also consumed. */
void ldbSendLogs(void) {
sds proto = sdsempty();
proto = sdscatfmt(proto,"*%i\r\n", (int)listLength(ldb.logs));
while(listLength(ldb.logs)) {
listNode *ln = listFirst(ldb.logs);
proto = sdscatlen(proto,"+",1);
sdsmapchars(ln->value,"\r\n"," ",2);
proto = sdscatsds(proto,ln->value);
proto = sdscatlen(proto,"\r\n",2);
listDelNode(ldb.logs,ln);
}
if (connWrite(ldb.conn,proto,sdslen(proto)) == -1) {
/* Avoid warning. We don't check the return value of write()
* since the next read() will catch the I/O error and will
* close the debugging session. */
}
sdsfree(proto);
}
/* Start a debugging session before calling EVAL implementation.
* The technique we use is to capture the client socket file descriptor,
* in order to perform direct I/O with it from within Lua hooks. This
* way we don't have to re-enter Redis in order to handle I/O.
*
* The function returns 1 if the caller should proceed to call EVAL,
* and 0 if instead the caller should abort the operation (this happens
* for the parent in a forked session, since it's up to the children
* to continue, or when fork returned an error).
*
* The caller should call ldbEndSession() only if ldbStartSession()
* returned 1. */
int ldbStartSession(client *c) {
ldb.forked = (c->flags & CLIENT_LUA_DEBUG_SYNC) == 0;
if (ldb.forked) {
pid_t cp = redisFork(CHILD_TYPE_LDB);
if (cp == -1) {
addReplyErrorFormat(c,"Fork() failed: can't run EVAL in debugging mode: %s", strerror(errno));
return 0;
} else if (cp == 0) {
/* Child. Let's ignore important signals handled by the parent. */
struct sigaction act;
sigemptyset(&act.sa_mask);
act.sa_flags = 0;
act.sa_handler = SIG_IGN;
sigaction(SIGTERM, &act, NULL);
sigaction(SIGINT, &act, NULL);
/* Log the creation of the child and close the listening
* socket to make sure if the parent crashes a reset is sent
* to the clients. */
serverLog(LL_WARNING,"Redis forked for debugging eval");
} else {
/* Parent */
listAddNodeTail(ldb.children,(void*)(unsigned long)cp);
freeClientAsync(c); /* Close the client in the parent side. */
return 0;
}
} else {
serverLog(LL_WARNING,
"Redis synchronous debugging eval session started");
}
/* Setup our debugging session. */
connBlock(ldb.conn);
connSendTimeout(ldb.conn,5000);
ldb.active = 1;
/* First argument of EVAL is the script itself. We split it into different
* lines since this is the way the debugger accesses the source code. */
sds srcstring = sdsdup(c->argv[1]->ptr);
size_t srclen = sdslen(srcstring);
while(srclen && (srcstring[srclen-1] == '\n' ||
srcstring[srclen-1] == '\r'))
{
srcstring[--srclen] = '\0';
}
sdssetlen(srcstring,srclen);
ldb.src = sdssplitlen(srcstring,sdslen(srcstring),"\n",1,&ldb.lines);
sdsfree(srcstring);
return 1;
}
/* End a debugging session after the EVAL call with debugging enabled
* returned. */
void ldbEndSession(client *c) {
/* Emit the remaining logs and an <endsession> mark. */
ldbLog(sdsnew("<endsession>"));
ldbSendLogs();
/* If it's a fork()ed session, we just exit. */
if (ldb.forked) {
writeToClient(c,0);
serverLog(LL_WARNING,"Lua debugging session child exiting");
exitFromChild(0);
} else {
serverLog(LL_WARNING,
"Redis synchronous debugging eval session ended");
}
/* Otherwise let's restore client's state. */
connNonBlock(ldb.conn);
connSendTimeout(ldb.conn,0);
/* Close the client connection after sending the final EVAL reply
* in order to signal the end of the debugging session. */
c->flags |= CLIENT_CLOSE_AFTER_REPLY;
/* Cleanup. */
sdsfreesplitres(ldb.src,ldb.lines);
ldb.lines = 0;
ldb.active = 0;
}
/* If the specified pid is among the list of children spawned for
* forked debugging sessions, it is removed from the children list.
* If the pid was found non-zero is returned. */
int ldbRemoveChild(pid_t pid) {
listNode *ln = listSearchKey(ldb.children,(void*)(unsigned long)pid);
if (ln) {
listDelNode(ldb.children,ln);
return 1;
}
return 0;
}
/* Return the number of children we still did not receive termination
* acknowledge via wait() in the parent process. */
int ldbPendingChildren(void) {
return listLength(ldb.children);
}
/* Kill all the forked sessions. */
void ldbKillForkedSessions(void) {
listIter li;
listNode *ln;
listRewind(ldb.children,&li);
while((ln = listNext(&li))) {
pid_t pid = (unsigned long) ln->value;
serverLog(LL_WARNING,"Killing debugging session %ld",(long)pid);
kill(pid,SIGKILL);
}
listRelease(ldb.children);
ldb.children = listCreate();
}
/* Wrapper for EVAL / EVALSHA that enables debugging, and makes sure
* that when EVAL returns, whatever happened, the session is ended. */
void evalGenericCommandWithDebugging(client *c, int evalsha) {
if (ldbStartSession(c)) {
evalGenericCommand(c,evalsha);
ldbEndSession(c);
} else {
ldbDisable(c);
}
}
/* Return a pointer to ldb.src source code line, considering line to be
* one-based, and returning a special string for out of range lines. */
char *ldbGetSourceLine(int line) {
int idx = line-1;
if (idx < 0 || idx >= ldb.lines) return "<out of range source code line>";
return ldb.src[idx];
}
/* Return true if there is a breakpoint in the specified line. */
int ldbIsBreakpoint(int line) {
int j;
for (j = 0; j < ldb.bpcount; j++)
if (ldb.bp[j] == line) return 1;
return 0;
}
/* Add the specified breakpoint. Ignore it if we already reached the max.
* Returns 1 if the breakpoint was added (or was already set). 0 if there is
* no space for the breakpoint or if the line is invalid. */
int ldbAddBreakpoint(int line) {
if (line <= 0 || line > ldb.lines) return 0;
if (!ldbIsBreakpoint(line) && ldb.bpcount != LDB_BREAKPOINTS_MAX) {
ldb.bp[ldb.bpcount++] = line;
return 1;
}
return 0;
}
/* Remove the specified breakpoint, returning 1 if the operation was
* performed or 0 if there was no such breakpoint. */
int ldbDelBreakpoint(int line) {
int j;
for (j = 0; j < ldb.bpcount; j++) {
if (ldb.bp[j] == line) {
ldb.bpcount--;
memmove(ldb.bp+j,ldb.bp+j+1,ldb.bpcount-j);
return 1;
}
}
return 0;
}
/* Expect a valid multi-bulk command in the debugging client query buffer.
* On success the command is parsed and returned as an array of SDS strings,
* otherwise NULL is returned and there is to read more buffer. */
sds *ldbReplParseCommand(int *argcp, char** err) {
static char* protocol_error = "protocol error";
sds *argv = NULL;
int argc = 0;
if (sdslen(ldb.cbuf) == 0) return NULL;
/* Working on a copy is simpler in this case. We can modify it freely
* for the sake of simpler parsing. */
sds copy = sdsdup(ldb.cbuf);
char *p = copy;
/* This Redis protocol parser is a joke... just the simplest thing that
* works in this context. It is also very forgiving regarding broken
* protocol. */
/* Seek and parse *<count>\r\n. */
p = strchr(p,'*'); if (!p) goto protoerr;
char *plen = p+1; /* Multi bulk len pointer. */
p = strstr(p,"\r\n"); if (!p) goto keep_reading;
*p = '\0'; p += 2;
*argcp = atoi(plen);
if (*argcp <= 0 || *argcp > 1024) goto protoerr;
/* Parse each argument. */
argv = zmalloc(sizeof(sds)*(*argcp));
argc = 0;
while(argc < *argcp) {
/* reached the end but there should be more data to read */
if (*p == '\0') goto keep_reading;
if (*p != '$') goto protoerr;
plen = p+1; /* Bulk string len pointer. */
p = strstr(p,"\r\n"); if (!p) goto keep_reading;
*p = '\0'; p += 2;
int slen = atoi(plen); /* Length of this arg. */
if (slen <= 0 || slen > 1024) goto protoerr;
if ((size_t)(p + slen + 2 - copy) > sdslen(copy) ) goto keep_reading;