/* * Copyright (c) 2009-2012, 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 "server.h" #include "cluster.h" #include "cluster_slot_stats.h" #include "script.h" #include "sds.h" #include "fpconv_dtoa.h" #include "fmtargs.h" #include "io_threads.h" #include #include #include #include #include #include static void setProtocolError(const char *errstr, client *c); static void pauseClientsByClient(mstime_t end, int isPauseClientAll); int postponeClientRead(client *c); char *getClientSockname(client *c); int ProcessingEventsWhileBlocked = 0; /* See processEventsWhileBlocked(). */ __thread sds thread_shared_qb = NULL; typedef enum { PARSE_OK = 0, PARSE_ERR = -1, PARSE_NEEDMORE = -2, } parseResult; /* Return the amount of memory used by the sds string at object->ptr * for a string object. This includes internal fragmentation. */ size_t getStringObjectSdsUsedMemory(robj *o) { serverAssertWithInfo(NULL, o, o->type == OBJ_STRING); if (o->encoding != OBJ_ENCODING_INT) { return sdsAllocSize(o->ptr); } return 0; } /* Return the length of a string object. * This does NOT include internal fragmentation or sds unused space. */ size_t getStringObjectLen(robj *o) { serverAssertWithInfo(NULL, o, o->type == OBJ_STRING); switch (o->encoding) { case OBJ_ENCODING_RAW: return sdslen(o->ptr); case OBJ_ENCODING_EMBSTR: return sdslen(o->ptr); default: return 0; /* Just integer encoding for now. */ } } /* Client.reply list dup and free methods. */ void *dupClientReplyValue(void *o) { clientReplyBlock *old = o; clientReplyBlock *buf = zmalloc(sizeof(clientReplyBlock) + old->size); memcpy(buf, o, sizeof(clientReplyBlock) + old->size); return buf; } void freeClientReplyValue(void *o) { zfree(o); } /* This function links the client to the global linked list of clients. * unlinkClient() does the opposite, among other things. */ void linkClient(client *c) { listAddNodeTail(server.clients, c); /* Note that we remember the linked list node where the client is stored, * this way removing the client in unlinkClient() will not require * a linear scan, but just a constant time operation. */ c->client_list_node = listLast(server.clients); uint64_t id = htonu64(c->id); raxInsert(server.clients_index, (unsigned char *)&id, sizeof(id), c, NULL); } /* Initialize client authentication state. */ static void clientSetDefaultAuth(client *c) { /* If the default user does not require authentication, the user is * directly authenticated. */ c->user = DefaultUser; c->flag.authenticated = (c->user->flags & USER_FLAG_NOPASS) && !(c->user->flags & USER_FLAG_DISABLED); } int authRequired(client *c) { /* Check if the user is authenticated. This check is skipped in case * the default user is flagged as "nopass" and is active. */ int auth_required = (!(DefaultUser->flags & USER_FLAG_NOPASS) || (DefaultUser->flags & USER_FLAG_DISABLED)) && !c->flag.authenticated; return auth_required; } static inline int isReplicaReadyForReplData(client *replica) { return (replica->repl_state == REPLICA_STATE_ONLINE || replica->repl_state == REPLICA_STATE_BG_RDB_LOAD) && !(replica->flag.close_asap); } client *createClient(connection *conn) { client *c = zmalloc(sizeof(client)); /* passing NULL as conn it is possible to create a non connected client. * This is useful since all the commands needs to be executed * in the context of a client. When commands are executed in other * contexts (for instance a Lua script) we need a non connected client. */ if (conn) { connEnableTcpNoDelay(conn); if (server.tcpkeepalive) connKeepAlive(conn, server.tcpkeepalive); connSetReadHandler(conn, readQueryFromClient); connSetPrivateData(conn, c); } c->buf = zmalloc_usable(PROTO_REPLY_CHUNK_BYTES, &c->buf_usable_size); selectDb(c, 0); uint64_t client_id = atomic_fetch_add_explicit(&server.next_client_id, 1, memory_order_relaxed); c->id = client_id; #ifdef LOG_REQ_RES reqresReset(c, 0); c->resp = server.client_default_resp; #else c->resp = 2; #endif c->conn = conn; c->name = NULL; c->lib_name = NULL; c->lib_ver = NULL; c->bufpos = 0; c->buf_peak = c->buf_usable_size; c->buf_peak_last_reset_time = server.unixtime; c->ref_repl_buf_node = NULL; c->ref_block_pos = 0; c->qb_pos = 0; c->querybuf = NULL; c->querybuf_peak = 0; c->reqtype = 0; c->argc = 0; c->argv = NULL; c->argv_len = 0; c->argv_len_sum = 0; c->original_argc = 0; c->original_argv = NULL; c->nread = 0; c->read_flags = 0; c->write_flags = 0; c->cmd = c->lastcmd = c->realcmd = c->io_parsed_cmd = NULL; c->cur_script = NULL; c->multibulklen = 0; c->bulklen = -1; c->sentlen = 0; c->raw_flag = 0; c->capa = 0; c->slot = -1; c->ctime = c->last_interaction = server.unixtime; c->duration = 0; clientSetDefaultAuth(c); c->repl_state = REPL_STATE_NONE; c->repl_start_cmd_stream_on_ack = 0; c->reploff = 0; c->read_reploff = 0; c->repl_applied = 0; c->repl_ack_off = 0; c->repl_ack_time = 0; c->repl_aof_off = 0; c->repl_last_partial_write = 0; c->replica_listening_port = 0; c->replica_addr = NULL; c->replica_version = 0; c->replica_capa = REPLICA_CAPA_NONE; c->replica_req = REPLICA_REQ_NONE; c->associated_rdb_client_id = 0; c->rdb_client_disconnect_time = 0; c->reply = listCreate(); c->deferred_reply_errors = NULL; c->reply_bytes = 0; c->obuf_soft_limit_reached_time = 0; listSetFreeMethod(c->reply, freeClientReplyValue); listSetDupMethod(c->reply, dupClientReplyValue); initClientBlockingState(c); c->woff = 0; c->watched_keys = listCreate(); c->pubsub_channels = dictCreate(&objectKeyPointerValueDictType); c->pubsub_patterns = dictCreate(&objectKeyPointerValueDictType); c->pubsubshard_channels = dictCreate(&objectKeyPointerValueDictType); c->peerid = NULL; c->sockname = NULL; c->client_list_node = NULL; c->io_read_state = CLIENT_IDLE; c->io_write_state = CLIENT_IDLE; c->nwritten = 0; c->client_tracking_redirection = 0; c->client_tracking_prefixes = NULL; c->last_memory_usage = 0; c->last_memory_type = CLIENT_TYPE_NORMAL; c->module_blocked_client = NULL; c->module_auth_ctx = NULL; c->auth_callback = NULL; c->auth_callback_privdata = NULL; c->auth_module = NULL; listInitNode(&c->clients_pending_write_node, c); listInitNode(&c->pending_read_list_node, c); c->mem_usage_bucket = NULL; c->mem_usage_bucket_node = NULL; if (conn) linkClient(c); initClientMultiState(c); c->net_input_bytes = 0; c->net_input_bytes_curr_cmd = 0; c->net_output_bytes = 0; c->net_output_bytes_curr_cmd = 0; c->commands_processed = 0; c->io_last_reply_block = NULL; c->io_last_bufpos = 0; return c; } void installClientWriteHandler(client *c) { int ae_barrier = 0; /* For the fsync=always policy, we want that a given FD is never * served for reading and writing in the same event loop iteration, * so that in the middle of receiving the query, and serving it * to the client, we'll call beforeSleep() that will do the * actual fsync of AOF to disk. the write barrier ensures that. */ if (server.aof_state == AOF_ON && server.aof_fsync == AOF_FSYNC_ALWAYS) { ae_barrier = 1; } if (connSetWriteHandlerWithBarrier(c->conn, sendReplyToClient, ae_barrier) == C_ERR) { freeClientAsync(c); } } /* This function puts the client in the queue of clients that should write * their output buffers to the socket. Note that it does not *yet* install * the write handler, to start clients are put in a queue of clients that need * to write, so we try to do that before returning in the event loop (see the * handleClientsWithPendingWrites() function). * If we fail and there is more data to write, compared to what the socket * buffers can hold, then we'll really install the handler. */ void putClientInPendingWriteQueue(client *c) { /* Schedule the client to write the output buffers to the socket only * if not already done and, for replicas, if the replica can actually receive * writes at this stage. */ if (!c->flag.pending_write && (c->repl_state == REPL_STATE_NONE || (isReplicaReadyForReplData(c) && !c->repl_start_cmd_stream_on_ack))) { /* Here instead of installing the write handler, we just flag the * client and put it into a list of clients that have something * to write to the socket. This way before re-entering the event * loop, we can try to directly write to the client sockets avoiding * a system call. We'll only really install the write handler if * we'll not be able to write the whole reply at once. */ c->flag.pending_write = 1; listLinkNodeHead(server.clients_pending_write, &c->clients_pending_write_node); } } /* This function is called every time we are going to transmit new data * to the client. The behavior is the following: * * If the client should receive new data (normal clients will) the function * returns C_OK, and make sure to install the write handler in our event * loop so that when the socket is writable new data gets written. * * If the client should not receive new data, because it is a fake client * (used to load AOF in memory), a primary or because the setup of the write * handler failed, the function returns C_ERR. * * The function may return C_OK without actually installing the write * event handler in the following cases: * * 1) The event handler should already be installed since the output buffer * already contains something. * 2) The client is a replica but not yet online, so we want to just accumulate * writes in the buffer but not actually sending them yet. * * Typically gets called every time a reply is built, before adding more * data to the clients output buffers. If the function returns C_ERR no * data should be appended to the output buffers. */ int prepareClientToWrite(client *c) { /* If it's the Lua client we always return ok without installing any * handler since there is no socket at all. */ if (c->flag.script || c->flag.module) return C_OK; /* If CLIENT_CLOSE_ASAP flag is set, we need not write anything. */ if (c->flag.close_asap) return C_ERR; /* CLIENT REPLY OFF / SKIP handling: don't send replies. * CLIENT_PUSHING handling: disables the reply silencing flags. */ if ((c->flag.reply_off || c->flag.reply_skip) && !c->flag.pushing) return C_ERR; /* Primaries don't receive replies, unless CLIENT_PRIMARY_FORCE_REPLY flag * is set. */ if (c->flag.primary && !c->flag.primary_force_reply) return C_ERR; if (!c->conn) return C_ERR; /* Fake client for AOF loading. */ /* Schedule the client to write the output buffers to the socket, unless * it should already be setup to do so (it has already pending data). */ if (!clientHasPendingReplies(c)) putClientInPendingWriteQueue(c); /* Authorize the caller to queue in the output buffer of this client. */ return C_OK; } /* Returns everything in the client reply linked list in a SDS format. * This should only be used only with a caching client. */ sds aggregateClientOutputBuffer(client *c) { sds cmd_response = sdsempty(); listIter li; listNode *ln; clientReplyBlock *val_block; listRewind(c->reply, &li); /* Here, c->buf is not used, thus we confirm c->bufpos remains 0. */ serverAssert(c->bufpos == 0); while ((ln = listNext(&li)) != NULL) { val_block = (clientReplyBlock *)listNodeValue(ln); cmd_response = sdscatlen(cmd_response, val_block->buf, val_block->used); } return cmd_response; } /* This function creates and returns a fake client for recording the command response * to initiate caching of any command response. * * It needs be paired with `deleteCachedResponseClient` function to stop caching. */ client *createCachedResponseClient(int resp) { struct client *recording_client = createClient(NULL); recording_client->resp = resp; /* Allocating the `conn` allows to prepare the caching client before adding * data to the clients output buffer by `prepareClientToWrite`. */ recording_client->conn = zcalloc(sizeof(connection)); recording_client->flag.fake = 1; return recording_client; } /* This function is used to stop caching of any command response after `createCachedResponseClient` is called. * It returns the command response as SDS from the recording_client's reply buffer. */ void deleteCachedResponseClient(client *recording_client) { zfree(recording_client->conn); recording_client->conn = NULL; freeClient(recording_client); } /* ----------------------------------------------------------------------------- * Low level functions to add more data to output buffers. * -------------------------------------------------------------------------- */ /* Attempts to add the reply to the static buffer in the client struct. * Returns the length of data that is added to the reply buffer. * * Sanitizer suppression: client->buf_usable_size determined by * zmalloc_usable_size() call. Writing beyond client->buf boundaries confuses * sanitizer and generates a false positive out-of-bounds error */ VALKEY_NO_SANITIZE("bounds") size_t _addReplyToBuffer(client *c, const char *s, size_t len) { size_t available = c->buf_usable_size - c->bufpos; /* If there already are entries in the reply list, we cannot * add anything more to the static buffer. */ if (listLength(c->reply) > 0) return 0; size_t reply_len = len > available ? available : len; memcpy(c->buf + c->bufpos, s, reply_len); c->bufpos += reply_len; /* We update the buffer peak after appending the reply to the buffer */ if (c->buf_peak < (size_t)c->bufpos) c->buf_peak = (size_t)c->bufpos; return reply_len; } /* Adds the reply to the reply linked list. * Note: some edits to this function need to be relayed to AddReplyFromClient. */ void _addReplyProtoToList(client *c, list *reply_list, const char *s, size_t len) { listNode *ln = listLast(reply_list); clientReplyBlock *tail = ln ? listNodeValue(ln) : NULL; /* Note that 'tail' may be NULL even if we have a tail node, because when * addReplyDeferredLen() is used, it sets a dummy node to NULL just * to fill it later, when the size of the bulk length is set. */ /* Append to tail string when possible. */ if (tail) { /* Copy the part we can fit into the tail, and leave the rest for a * new node */ size_t avail = tail->size - tail->used; size_t copy = avail >= len ? len : avail; memcpy(tail->buf + tail->used, s, copy); tail->used += copy; s += copy; len -= copy; } if (len) { /* Create a new node, make sure it is allocated to at * least PROTO_REPLY_CHUNK_BYTES */ size_t usable_size; size_t size = len < PROTO_REPLY_CHUNK_BYTES ? PROTO_REPLY_CHUNK_BYTES : len; tail = zmalloc_usable(size + sizeof(clientReplyBlock), &usable_size); /* take over the allocation's internal fragmentation */ tail->size = usable_size - sizeof(clientReplyBlock); tail->used = len; memcpy(tail->buf, s, len); listAddNodeTail(reply_list, tail); c->reply_bytes += tail->size; closeClientOnOutputBufferLimitReached(c, 1); } } /* The subscribe / unsubscribe command family has a push as a reply, * or in other words, it responds with a push (or several of them * depending on how many arguments it got), and has no reply. */ int cmdHasPushAsReply(struct serverCommand *cmd) { if (!cmd) return 0; return cmd->proc == subscribeCommand || cmd->proc == unsubscribeCommand || cmd->proc == psubscribeCommand || cmd->proc == punsubscribeCommand || cmd->proc == ssubscribeCommand || cmd->proc == sunsubscribeCommand; } void _addReplyToBufferOrList(client *c, const char *s, size_t len) { if (c->flag.close_after_reply) return; /* Replicas should normally not cause any writes to the reply buffer. In case a rogue replica sent a command on the * replication link that caused a reply to be generated we'll simply disconnect it. * Note this is the simplest way to check a command added a response. Replication links are used to write data but * not for responses, so we should normally never get here on a replica client. */ if (getClientType(c) == CLIENT_TYPE_REPLICA) { sds cmdname = c->lastcmd ? c->lastcmd->fullname : NULL; logInvalidUseAndFreeClientAsync(c, "Replica generated a reply to command '%s'", cmdname ? cmdname : ""); return; } c->net_output_bytes_curr_cmd += len; /* We call it here because this function may affect the reply * buffer offset (see function comment) */ reqresSaveClientReplyOffset(c); /* If we're processing a push message into the current client (i.e. executing PUBLISH * to a channel which we are subscribed to, then we wanna postpone that message to be added * after the command's reply (specifically important during multi-exec). the exception is * the SUBSCRIBE command family, which (currently) have a push message instead of a proper reply. * The check for executing_client also avoids affecting push messages that are part of eviction. * Check CLIENT_PUSHING first to avoid race conditions, as it's absent in module's fake client. */ if (c->flag.pushing && c == server.current_client && server.executing_client && !cmdHasPushAsReply(server.executing_client->cmd)) { _addReplyProtoToList(c, server.pending_push_messages, s, len); return; } size_t reply_len = _addReplyToBuffer(c, s, len); if (len > reply_len) _addReplyProtoToList(c, c->reply, s + reply_len, len - reply_len); } /* ----------------------------------------------------------------------------- * Higher level functions to queue data on the client output buffer. * The following functions are the ones that commands implementations will call. * -------------------------------------------------------------------------- */ /* Add the object 'obj' string representation to the client output buffer. */ void addReply(client *c, robj *obj) { if (prepareClientToWrite(c) != C_OK) return; if (sdsEncodedObject(obj)) { _addReplyToBufferOrList(c, obj->ptr, sdslen(obj->ptr)); } else if (obj->encoding == OBJ_ENCODING_INT) { /* For integer encoded strings we just convert it into a string * using our optimized function, and attach the resulting string * to the output buffer. */ char buf[32]; size_t len = ll2string(buf, sizeof(buf), (long)obj->ptr); _addReplyToBufferOrList(c, buf, len); } else { serverPanic("Wrong obj->encoding in addReply()"); } } /* Add the SDS 's' string to the client output buffer, as a side effect * the SDS string is freed. */ void addReplySds(client *c, sds s) { if (prepareClientToWrite(c) != C_OK) { /* The caller expects the sds to be free'd. */ sdsfree(s); return; } _addReplyToBufferOrList(c, s, sdslen(s)); sdsfree(s); } /* This low level function just adds whatever protocol you send it to the * client buffer, trying the static buffer initially, and using the string * of objects if not possible. * * It is efficient because does not create an SDS object nor an Object * if not needed. The object will only be created by calling * _addReplyProtoToList() if we fail to extend the existing tail object * in the list of objects. */ void addReplyProto(client *c, const char *s, size_t len) { if (prepareClientToWrite(c) != C_OK) return; _addReplyToBufferOrList(c, s, len); } /* Low level function called by the addReplyError...() functions. * It emits the protocol for an error reply, in the form: * * -ERRORCODE Error Message * * If the error code is already passed in the string 's', the error * code provided is used, otherwise the string "-ERR " for the generic * error code is automatically added. * Note that 's' must NOT end with \r\n. */ void addReplyErrorLength(client *c, const char *s, size_t len) { /* If the string already starts with "-..." then the error code * is provided by the caller. Otherwise we use "-ERR". */ if (!len || s[0] != '-') addReplyProto(c, "-ERR ", 5); addReplyProto(c, s, len); addReplyProto(c, "\r\n", 2); } /* Do some actions after an error reply was sent (Log if needed, updates stats, etc.) * Possible flags: * * ERR_REPLY_FLAG_NO_STATS_UPDATE - indicate not to update any error stats. */ void afterErrorReply(client *c, const char *s, size_t len, int flags) { /* Module clients fall into two categories: * Calls to RM_Call, in which case the error isn't being returned to a client, so should not be counted. * Module thread safe context calls to RM_ReplyWithError, which will be added to a real client by the main thread * later. */ if (c->flag.module) { if (!c->deferred_reply_errors) { c->deferred_reply_errors = listCreate(); listSetFreeMethod(c->deferred_reply_errors, (void (*)(void *))sdsfree); } listAddNodeTail(c->deferred_reply_errors, sdsnewlen(s, len)); return; } if (!(flags & ERR_REPLY_FLAG_NO_STATS_UPDATE)) { /* Increment the global error counter */ server.stat_total_error_replies++; /* Increment the error stats * If the string already starts with "-..." then the error prefix * is provided by the caller (we limit the search to 32 chars). Otherwise we use "-ERR". */ char *err_prefix = "ERR"; size_t prefix_len = 3; if (s[0] == '-') { char *spaceloc = memchr(s, ' ', len < 32 ? len : 32); /* If we cannot retrieve the error prefix, use the default: "ERR". */ if (spaceloc) { const size_t errEndPos = (size_t)(spaceloc - s); err_prefix = (char *)s + 1; prefix_len = errEndPos - 1; } } /* After the errors RAX reaches its limit, instead of tracking * custom errors (e.g. LUA), we track the error under `errorstat_ERRORSTATS_OVERFLOW` */ if (flags & ERR_REPLY_FLAG_CUSTOM && raxSize(server.errors) >= ERRORSTATS_LIMIT && !raxFind(server.errors, (unsigned char *)err_prefix, prefix_len, NULL)) { err_prefix = ERRORSTATS_OVERFLOW_ERR; prefix_len = strlen(ERRORSTATS_OVERFLOW_ERR); } incrementErrorCount(err_prefix, prefix_len); } else { /* stat_total_error_replies will not be updated, which means that * the cmd stats will not be updated as well, we still want this command * to be counted as failed so we update it here. We update c->realcmd in * case c->cmd was changed (like in GEOADD). */ c->realcmd->failed_calls++; } /* Sometimes it could be normal that a replica replies to a primary with * an error and this function gets called. Actually the error will never * be sent because addReply*() against primary clients has no effect... * * It can happen when the versions are different and replica cannot recognize * the commands sent by the primary. However it is useful to log such events since * they are rare and may hint at errors in a script or a bug in the server. */ int ctype = getClientType(c); if (ctype == CLIENT_TYPE_PRIMARY || ctype == CLIENT_TYPE_REPLICA || c->id == CLIENT_ID_AOF) { char *to, *from; if (c->id == CLIENT_ID_AOF) { to = "AOF-loading-client"; from = "server"; } else if (ctype == CLIENT_TYPE_PRIMARY) { to = "primary"; from = "replica"; } else { to = "replica"; from = "primary"; } if (len > 4096) len = 4096; sds cmdname = c->lastcmd ? c->lastcmd->fullname : NULL; serverLog(LL_WARNING, "== CRITICAL == This %s is sending an error " "to its %s: '%.*s' after processing the command " "'%s'", from, to, (int)len, s, cmdname ? cmdname : ""); if (ctype == CLIENT_TYPE_PRIMARY && server.repl_backlog && server.repl_backlog->histlen > 0) { showLatestBacklog(); } server.stat_unexpected_error_replies++; /* Based off the propagation error behavior, check if we need to panic here. There * are currently two checked cases: * * If this command was from our primary and we are not a writable replica. * * We are reading from an AOF file. */ int panic_in_replicas = (ctype == CLIENT_TYPE_PRIMARY && server.repl_replica_ro) && (server.propagation_error_behavior == PROPAGATION_ERR_BEHAVIOR_PANIC || server.propagation_error_behavior == PROPAGATION_ERR_BEHAVIOR_PANIC_ON_REPLICAS); int panic_in_aof = c->id == CLIENT_ID_AOF && server.propagation_error_behavior == PROPAGATION_ERR_BEHAVIOR_PANIC; if (panic_in_replicas || panic_in_aof) { serverPanic("This %s panicked sending an error to its %s" " after processing the command '%s'", from, to, cmdname ? cmdname : ""); } } } /* The 'err' object is expected to start with -ERRORCODE and end with \r\n. * Unlike addReplyErrorSds and others alike which rely on addReplyErrorLength. */ void addReplyErrorObject(client *c, robj *err) { addReply(c, err); afterErrorReply(c, err->ptr, sdslen(err->ptr) - 2, 0); /* Ignore trailing \r\n */ } /* Sends either a reply or an error reply by checking the first char. * If the first char is '-' the reply is considered an error. * In any case the given reply is sent, if the reply is also recognize * as an error we also perform some post reply operations such as * logging and stats update. */ void addReplyOrErrorObject(client *c, robj *reply) { serverAssert(sdsEncodedObject(reply)); sds rep = reply->ptr; if (sdslen(rep) > 1 && rep[0] == '-') { addReplyErrorObject(c, reply); } else { addReply(c, reply); } } /* See addReplyErrorLength for expectations from the input string. */ void addReplyError(client *c, const char *err) { addReplyErrorLength(c, err, strlen(err)); afterErrorReply(c, err, strlen(err), 0); } /* Add error reply to the given client. * Supported flags: * * ERR_REPLY_FLAG_NO_STATS_UPDATE - indicate not to perform any error stats updates */ void addReplyErrorSdsEx(client *c, sds err, int flags) { addReplyErrorLength(c, err, sdslen(err)); afterErrorReply(c, err, sdslen(err), flags); sdsfree(err); } /* See addReplyErrorLength for expectations from the input string. */ /* As a side effect the SDS string is freed. */ void addReplyErrorSds(client *c, sds err) { addReplyErrorSdsEx(c, err, 0); } /* See addReplyErrorLength for expectations from the input string. */ /* As a side effect the SDS string is freed. */ void addReplyErrorSdsSafe(client *c, sds err) { err = sdsmapchars(err, "\r\n", " ", 2); addReplyErrorSdsEx(c, err, 0); } /* Internal function used by addReplyErrorFormat, addReplyErrorFormatEx and RM_ReplyWithErrorFormat. * Refer to afterErrorReply for more information about the flags. */ void addReplyErrorFormatInternal(client *c, int flags, const char *fmt, va_list ap) { va_list cpy; va_copy(cpy, ap); sds s = sdscatvprintf(sdsempty(), fmt, cpy); va_end(cpy); /* Trim any newlines at the end (ones will be added by addReplyErrorLength) */ s = sdstrim(s, "\r\n"); /* Make sure there are no newlines in the middle of the string, otherwise * invalid protocol is emitted. */ s = sdsmapchars(s, "\r\n", " ", 2); addReplyErrorLength(c, s, sdslen(s)); afterErrorReply(c, s, sdslen(s), flags); sdsfree(s); } void addReplyErrorFormatEx(client *c, int flags, const char *fmt, ...) { va_list ap; va_start(ap, fmt); addReplyErrorFormatInternal(c, flags, fmt, ap); va_end(ap); } /* See addReplyErrorLength for expectations from the formatted string. * The formatted string is safe to contain \r and \n anywhere. */ void addReplyErrorFormat(client *c, const char *fmt, ...) { va_list ap; va_start(ap, fmt); addReplyErrorFormatInternal(c, 0, fmt, ap); va_end(ap); } void addReplyErrorArity(client *c) { addReplyErrorFormat(c, "wrong number of arguments for '%s' command", c->cmd->fullname); } void addReplyErrorExpireTime(client *c) { addReplyErrorFormat(c, "invalid expire time in '%s' command", c->cmd->fullname); } void addReplyStatusLength(client *c, const char *s, size_t len) { addReplyProto(c, "+", 1); addReplyProto(c, s, len); addReplyProto(c, "\r\n", 2); } void addReplyStatus(client *c, const char *status) { addReplyStatusLength(c, status, strlen(status)); } void addReplyStatusFormat(client *c, const char *fmt, ...) { va_list ap; va_start(ap, fmt); sds s = sdscatvprintf(sdsempty(), fmt, ap); va_end(ap); addReplyStatusLength(c, s, sdslen(s)); sdsfree(s); } /* Sometimes we are forced to create a new reply node, and we can't append to * the previous one, when that happens, we wanna try to trim the unused space * at the end of the last reply node which we won't use anymore. */ void trimReplyUnusedTailSpace(client *c) { listNode *ln = listLast(c->reply); clientReplyBlock *tail = ln ? listNodeValue(ln) : NULL; /* Note that 'tail' may be NULL even if we have a tail node, because when * addReplyDeferredLen() is used */ if (!tail) return; /* We only try to trim the space is relatively high (more than a 1/4 of the * allocation), otherwise there's a high chance realloc will NOP. * Also, to avoid large memmove which happens as part of realloc, we only do * that if the used part is small. */ if (tail->size - tail->used > tail->size / 4 && tail->used < PROTO_REPLY_CHUNK_BYTES && c->io_write_state != CLIENT_PENDING_IO) { size_t usable_size; size_t old_size = tail->size; tail = zrealloc_usable(tail, tail->used + sizeof(clientReplyBlock), &usable_size); /* take over the allocation's internal fragmentation (at least for * memory usage tracking) */ tail->size = usable_size - sizeof(clientReplyBlock); c->reply_bytes = c->reply_bytes + tail->size - old_size; listNodeValue(ln) = tail; } } /* Adds an empty object to the reply list that will contain the multi bulk * length, which is not known when this function is called. */ void *addReplyDeferredLen(client *c) { /* Note that we install the write event here even if the object is not * ready to be sent, since we are sure that before returning to the * event loop setDeferredAggregateLen() will be called. */ if (prepareClientToWrite(c) != C_OK) return NULL; /* Replicas should normally not cause any writes to the reply buffer. In case a rogue replica sent a command on the * replication link that caused a reply to be generated we'll simply disconnect it. * Note this is the simplest way to check a command added a response. Replication links are used to write data but * not for responses, so we should normally never get here on a replica client. */ if (getClientType(c) == CLIENT_TYPE_REPLICA) { sds cmdname = c->lastcmd ? c->lastcmd->fullname : NULL; logInvalidUseAndFreeClientAsync(c, "Replica generated a reply to command '%s'", cmdname ? cmdname : ""); return NULL; } /* We call it here because this function conceptually affects the reply * buffer offset (see function comment) */ reqresSaveClientReplyOffset(c); trimReplyUnusedTailSpace(c); listAddNodeTail(c->reply, NULL); /* NULL is our placeholder. */ return listLast(c->reply); } void setDeferredReply(client *c, void *node, const char *s, size_t length) { listNode *ln = (listNode *)node; clientReplyBlock *next, *prev; /* Abort when *node is NULL: when the client should not accept writes * we return NULL in addReplyDeferredLen() */ if (node == NULL) return; serverAssert(!listNodeValue(ln)); /* Normally we fill this dummy NULL node, added by addReplyDeferredLen(), * with a new buffer structure containing the protocol needed to specify * the length of the array following. However sometimes there might be room * in the previous/next node so we can instead remove this NULL node, and * suffix/prefix our data in the node immediately before/after it, in order * to save a write(2) syscall later. Conditions needed to do it: * * - The prev node is non-NULL and has space in it or * - The next node is non-NULL, * - It has enough room already allocated * - And not too large (avoid large memmove) * - And the client is not in a pending I/O state */ if (ln->prev != NULL && (prev = listNodeValue(ln->prev)) && prev->size - prev->used > 0 && c->io_write_state != CLIENT_PENDING_IO) { size_t len_to_copy = prev->size - prev->used; if (len_to_copy > length) len_to_copy = length; memcpy(prev->buf + prev->used, s, len_to_copy); prev->used += len_to_copy; length -= len_to_copy; if (length == 0) { listDelNode(c->reply, ln); return; } s += len_to_copy; } if (ln->next != NULL && (next = listNodeValue(ln->next)) && next->size - next->used >= length && next->used < PROTO_REPLY_CHUNK_BYTES * 4 && c->io_write_state != CLIENT_PENDING_IO) { memmove(next->buf + length, next->buf, next->used); memcpy(next->buf, s, length); next->used += length; listDelNode(c->reply, ln); } else { /* Create a new node */ size_t usable_size; clientReplyBlock *buf = zmalloc_usable(length + sizeof(clientReplyBlock), &usable_size); /* Take over the allocation's internal fragmentation */ buf->size = usable_size - sizeof(clientReplyBlock); buf->used = length; memcpy(buf->buf, s, length); listNodeValue(ln) = buf; c->reply_bytes += buf->size; closeClientOnOutputBufferLimitReached(c, 1); } } /* Populate the length object and try gluing it to the next chunk. */ void setDeferredAggregateLen(client *c, void *node, long length, char prefix) { serverAssert(length >= 0); /* Abort when *node is NULL: when the client should not accept writes * we return NULL in addReplyDeferredLen() */ if (node == NULL) return; /* Things like *2\r\n, %3\r\n or ~4\r\n are emitted very often by the protocol * so we have a few shared objects to use if the integer is small * like it is most of the times. */ const size_t hdr_len = OBJ_SHARED_HDR_STRLEN(length); const int opt_hdr = length < OBJ_SHARED_BULKHDR_LEN; if (prefix == '*' && opt_hdr) { setDeferredReply(c, node, shared.mbulkhdr[length]->ptr, hdr_len); return; } if (prefix == '%' && opt_hdr) { setDeferredReply(c, node, shared.maphdr[length]->ptr, hdr_len); return; } if (prefix == '~' && opt_hdr) { setDeferredReply(c, node, shared.sethdr[length]->ptr, hdr_len); return; } char lenstr[128]; size_t lenstr_len = snprintf(lenstr, sizeof(lenstr), "%c%ld\r\n", prefix, length); setDeferredReply(c, node, lenstr, lenstr_len); } void setDeferredArrayLen(client *c, void *node, long length) { setDeferredAggregateLen(c, node, length, '*'); } void setDeferredMapLen(client *c, void *node, long length) { int prefix = c->resp == 2 ? '*' : '%'; if (c->resp == 2) length *= 2; setDeferredAggregateLen(c, node, length, prefix); } void setDeferredSetLen(client *c, void *node, long length) { int prefix = c->resp == 2 ? '*' : '~'; setDeferredAggregateLen(c, node, length, prefix); } void setDeferredAttributeLen(client *c, void *node, long length) { serverAssert(c->resp >= 3); setDeferredAggregateLen(c, node, length, '|'); } void setDeferredPushLen(client *c, void *node, long length) { serverAssert(c->resp >= 3); setDeferredAggregateLen(c, node, length, '>'); } /* Prepare a client for future writes. This is used so that we can * skip a large number of calls to prepareClientToWrite when * a command produces a lot of discrete elements in its output. */ writePreparedClient *prepareClientForFutureWrites(client *c) { if (prepareClientToWrite(c) == C_OK) { return (writePreparedClient *)c; } return NULL; } /* Add a double as a bulk reply */ void addReplyDouble(client *c, double d) { if (c->resp == 3) { char dbuf[MAX_D2STRING_CHARS + 3]; dbuf[0] = ','; const int dlen = d2string(dbuf + 1, sizeof(dbuf) - 1, d); dbuf[dlen + 1] = '\r'; dbuf[dlen + 2] = '\n'; dbuf[dlen + 3] = '\0'; addReplyProto(c, dbuf, dlen + 3); } else { char dbuf[MAX_LONG_DOUBLE_CHARS + 32]; /* In order to prepend the string length before the formatted number, * but still avoid an extra memcpy of the whole number, we reserve space * for maximum header `$0000\r\n`, print double, add the resp header in * front of it, and then send the buffer with the right `start` offset. */ const int dlen = d2string(dbuf + 7, sizeof(dbuf) - 7, d); int digits = digits10(dlen); int start = 4 - digits; serverAssert(start >= 0); dbuf[start] = '$'; /* Convert `dlen` to string, putting it's digits after '$' and before the * formatted double string. */ for (int i = digits, val = dlen; val && i > 0; --i, val /= 10) { dbuf[start + i] = "0123456789"[val % 10]; } dbuf[5] = '\r'; dbuf[6] = '\n'; dbuf[dlen + 7] = '\r'; dbuf[dlen + 8] = '\n'; dbuf[dlen + 9] = '\0'; addReplyProto(c, dbuf + start, dlen + 9 - start); } } void addReplyBigNum(client *c, const char *num, size_t len) { if (c->resp == 2) { addReplyBulkCBuffer(c, num, len); } else { addReplyProto(c, "(", 1); addReplyProto(c, num, len); addReplyProto(c, "\r\n", 2); } } /* Add a long double as a bulk reply, but uses a human readable formatting * of the double instead of exposing the crude behavior of doubles to the * dear user. */ void addReplyHumanLongDouble(client *c, long double d) { if (c->resp == 2) { robj *o = createStringObjectFromLongDouble(d, 1); addReplyBulk(c, o); decrRefCount(o); } else { char buf[MAX_LONG_DOUBLE_CHARS]; int len = ld2string(buf, sizeof(buf), d, LD_STR_HUMAN); addReplyProto(c, ",", 1); addReplyProto(c, buf, len); addReplyProto(c, "\r\n", 2); } } /* Add a long long as integer reply or bulk len / multi bulk count. * Basically this is used to output . */ static void _addReplyLongLongWithPrefix(client *c, long long ll, char prefix) { char buf[128]; int len; /* Things like $3\r\n or *2\r\n are emitted very often by the protocol * so we have a few shared objects to use if the integer is small * like it is most of the times. */ const int opt_hdr = ll < OBJ_SHARED_BULKHDR_LEN && ll >= 0; const size_t hdr_len = OBJ_SHARED_HDR_STRLEN(ll); if (prefix == '*' && opt_hdr) { _addReplyToBufferOrList(c, shared.mbulkhdr[ll]->ptr, hdr_len); return; } else if (prefix == '$' && opt_hdr) { _addReplyToBufferOrList(c, shared.bulkhdr[ll]->ptr, hdr_len); return; } else if (prefix == '%' && opt_hdr) { _addReplyToBufferOrList(c, shared.maphdr[ll]->ptr, hdr_len); return; } else if (prefix == '~' && opt_hdr) { _addReplyToBufferOrList(c, shared.sethdr[ll]->ptr, hdr_len); return; } buf[0] = prefix; len = ll2string(buf + 1, sizeof(buf) - 1, ll); buf[len + 1] = '\r'; buf[len + 2] = '\n'; _addReplyToBufferOrList(c, buf, len + 3); } void addReplyLongLong(client *c, long long ll) { if (ll == 0) addReply(c, shared.czero); else if (ll == 1) addReply(c, shared.cone); else { if (prepareClientToWrite(c) != C_OK) return; _addReplyLongLongWithPrefix(c, ll, ':'); } } void addReplyAggregateLen(client *c, long length, int prefix) { serverAssert(length >= 0); if (prepareClientToWrite(c) != C_OK) return; _addReplyLongLongWithPrefix(c, length, prefix); } void addReplyArrayLen(client *c, long length) { addReplyAggregateLen(c, length, '*'); } void addWritePreparedReplyArrayLen(writePreparedClient *c, long length) { serverAssert(length >= 0); _addReplyLongLongWithPrefix(c, length, '*'); } void addReplyMapLen(client *c, long length) { int prefix = c->resp == 2 ? '*' : '%'; if (c->resp == 2) length *= 2; addReplyAggregateLen(c, length, prefix); } void addReplySetLen(client *c, long length) { int prefix = c->resp == 2 ? '*' : '~'; addReplyAggregateLen(c, length, prefix); } void addReplyAttributeLen(client *c, long length) { serverAssert(c->resp >= 3); addReplyAggregateLen(c, length, '|'); } void addReplyPushLen(client *c, long length) { serverAssert(c->resp >= 3); serverAssertWithInfo(c, NULL, c->flag.pushing); addReplyAggregateLen(c, length, '>'); } void addReplyNull(client *c) { if (c->resp == 2) { addReplyProto(c, "$-1\r\n", 5); } else { addReplyProto(c, "_\r\n", 3); } } void addReplyBool(client *c, int b) { if (c->resp == 2) { addReply(c, b ? shared.cone : shared.czero); } else { addReplyProto(c, b ? "#t\r\n" : "#f\r\n", 4); } } /* A null array is a concept that no longer exists in RESP3. However * RESP2 had it, so API-wise we have this call, that will emit the correct * RESP2 protocol, however for RESP3 the reply will always be just the * Null type "_\r\n". */ void addReplyNullArray(client *c) { if (c->resp == 2) { addReplyProto(c, "*-1\r\n", 5); } else { addReplyProto(c, "_\r\n", 3); } } /* Create the length prefix of a bulk reply, example: $2234 */ void addReplyBulkLen(client *c, robj *obj) { size_t len = stringObjectLen(obj); if (prepareClientToWrite(c) != C_OK) return; _addReplyLongLongWithPrefix(c, len, '$'); } /* Add an Object as a bulk reply */ void addReplyBulk(client *c, robj *obj) { addReplyBulkLen(c, obj); addReply(c, obj); addReplyProto(c, "\r\n", 2); } /* Add a C buffer as bulk reply */ void addReplyBulkCBuffer(client *c, const void *p, size_t len) { if (prepareClientToWrite(c) != C_OK) return; _addReplyLongLongWithPrefix(c, len, '$'); _addReplyToBufferOrList(c, p, len); _addReplyToBufferOrList(c, "\r\n", 2); } void addWritePreparedReplyBulkCBuffer(writePreparedClient *c, const void *p, size_t len) { _addReplyLongLongWithPrefix(c, len, '$'); _addReplyToBufferOrList(c, p, len); _addReplyToBufferOrList(c, "\r\n", 2); } /* Add sds to reply (takes ownership of sds and frees it) */ void addReplyBulkSds(client *c, sds s) { if (prepareClientToWrite(c) != C_OK) { sdsfree(s); return; } _addReplyLongLongWithPrefix(c, sdslen(s), '$'); _addReplyToBufferOrList(c, s, sdslen(s)); sdsfree(s); _addReplyToBufferOrList(c, "\r\n", 2); } /* Set sds to a deferred reply (for symmetry with addReplyBulkSds it also frees the sds) */ void setDeferredReplyBulkSds(client *c, void *node, sds s) { sds reply = sdscatprintf(sdsempty(), "$%d\r\n%s\r\n", (unsigned)sdslen(s), s); setDeferredReply(c, node, reply, sdslen(reply)); sdsfree(reply); sdsfree(s); } /* Add a C null term string as bulk reply */ void addReplyBulkCString(client *c, const char *s) { if (s == NULL) { addReplyNull(c); } else { addReplyBulkCBuffer(c, s, strlen(s)); } } /* Add a long long as a bulk reply */ void addReplyBulkLongLong(client *c, long long ll) { char buf[64]; int len; len = ll2string(buf, 64, ll); addReplyBulkCBuffer(c, buf, len); } void addWritePreparedReplyBulkLongLong(writePreparedClient *c, long long ll) { char buf[64]; int len; len = ll2string(buf, 64, ll); addWritePreparedReplyBulkCBuffer(c, buf, len); } /* Reply with a verbatim type having the specified extension. * * The 'ext' is the "extension" of the file, actually just a three * character type that describes the format of the verbatim string. * For instance "txt" means it should be interpreted as a text only * file by the receiver, "md " as markdown, and so forth. Only the * three first characters of the extension are used, and if the * provided one is shorter than that, the remaining is filled with * spaces. */ void addReplyVerbatim(client *c, const char *s, size_t len, const char *ext) { if (c->resp == 2) { addReplyBulkCBuffer(c, s, len); } else { char buf[32]; size_t preflen = snprintf(buf, sizeof(buf), "=%zu\r\nxxx:", len + 4); char *p = buf + preflen - 4; for (int i = 0; i < 3; i++) { if (*ext == '\0') { p[i] = ' '; } else { p[i] = *ext++; } } addReplyProto(c, buf, preflen); addReplyProto(c, s, len); addReplyProto(c, "\r\n", 2); } } /* This function is similar to the addReplyHelp function but adds the * ability to pass in two arrays of strings. Some commands have * some additional subcommands based on the specific feature implementation * the server is compiled with (currently just clustering). This function allows * to pass is the common subcommands in `help` and any implementation * specific subcommands in `extended_help`. */ void addExtendedReplyHelp(client *c, const char **help, const char **extended_help) { sds cmd = sdsnew((char *)c->argv[0]->ptr); void *blenp = addReplyDeferredLen(c); int blen = 0; int idx = 0; sdstoupper(cmd); addReplyStatusFormat(c, "%s [ [value] [opt] ...]. Subcommands are:", cmd); sdsfree(cmd); while (help[blen]) addReplyStatus(c, help[blen++]); if (extended_help) { while (extended_help[idx]) addReplyStatus(c, extended_help[idx++]); } blen += idx; addReplyStatus(c, "HELP"); addReplyStatus(c, " Print this help."); blen += 1; /* Account for the header. */ blen += 2; /* Account for the footer. */ setDeferredArrayLen(c, blenp, blen); } /* Add an array of C strings as status replies with a heading. * This function is typically invoked by commands that support * subcommands in response to the 'help' subcommand. The help array * is terminated by NULL sentinel. */ void addReplyHelp(client *c, const char **help) { addExtendedReplyHelp(c, help, NULL); } /* Add a suggestive error reply. * This function is typically invoked by from commands that support * subcommands in response to an unknown subcommand or argument error. */ void addReplySubcommandSyntaxError(client *c) { sds cmd = sdsnew((char *)c->argv[0]->ptr); sdstoupper(cmd); addReplyErrorFormat(c, "unknown subcommand or wrong number of arguments for '%.128s'. Try %s HELP.", (char *)c->argv[1]->ptr, cmd); sdsfree(cmd); } /* Append 'src' client output buffers into 'dst' client output buffers. * This function clears the output buffers of 'src' */ void AddReplyFromClient(client *dst, client *src) { /* If the source client contains a partial response due to client output * buffer limits, propagate that to the dest rather than copy a partial * reply. We don't wanna run the risk of copying partial response in case * for some reason the output limits don't reach the same decision (maybe * they changed) */ if (src->flag.close_asap) { sds client = catClientInfoString(sdsempty(), dst, server.hide_user_data_from_log); freeClientAsync(dst); serverLog(LL_WARNING, "Client %s scheduled to be closed ASAP for overcoming of output buffer limits.", client); sdsfree(client); return; } /* First add the static buffer (either into the static buffer or reply list) */ addReplyProto(dst, src->buf, src->bufpos); /* We need to check with prepareClientToWrite again (after addReplyProto) * since addReplyProto may have changed something (like CLIENT_CLOSE_ASAP) */ if (prepareClientToWrite(dst) != C_OK) return; /* We're bypassing _addReplyProtoToList, so we need to add the pre/post * checks in it. */ if (dst->flag.close_after_reply) return; /* Concatenate the reply list into the dest */ if (listLength(src->reply)) listJoin(dst->reply, src->reply); dst->reply_bytes += src->reply_bytes; src->reply_bytes = 0; src->bufpos = 0; if (src->deferred_reply_errors) { deferredAfterErrorReply(dst, src->deferred_reply_errors); listRelease(src->deferred_reply_errors); src->deferred_reply_errors = NULL; } /* Check output buffer limits */ closeClientOnOutputBufferLimitReached(dst, 1); } /* Append the listed errors to the server error statistics. the input * list is not modified and remains the responsibility of the caller. */ void deferredAfterErrorReply(client *c, list *errors) { listIter li; listNode *ln; listRewind(errors, &li); while ((ln = listNext(&li))) { sds err = ln->value; afterErrorReply(c, err, sdslen(err), 0); } } /* Logically copy 'src' replica client buffers info to 'dst' replica. * Basically increase referenced buffer block node reference count. */ void copyReplicaOutputBuffer(client *dst, client *src) { serverAssert(src->bufpos == 0 && listLength(src->reply) == 0); if (src->ref_repl_buf_node == NULL) return; dst->ref_repl_buf_node = src->ref_repl_buf_node; dst->ref_block_pos = src->ref_block_pos; ((replBufBlock *)listNodeValue(dst->ref_repl_buf_node))->refcount++; } /* Return true if the specified client has pending reply buffers to write to * the socket. */ int clientHasPendingReplies(client *c) { if (getClientType(c) == CLIENT_TYPE_REPLICA) { /* Replicas use global shared replication buffer instead of * private output buffer. */ serverAssert(c->bufpos == 0 && listLength(c->reply) == 0); if (c->ref_repl_buf_node == NULL) return 0; /* If the last replication buffer block content is totally sent, * we have nothing to send. */ listNode *ln = listLast(server.repl_buffer_blocks); replBufBlock *tail = listNodeValue(ln); if (ln == c->ref_repl_buf_node && c->ref_block_pos == tail->used) return 0; return 1; } else { return c->bufpos || listLength(c->reply); } } void clientAcceptHandler(connection *conn) { client *c = connGetPrivateData(conn); if (connGetState(conn) != CONN_STATE_CONNECTED) { serverLog(LL_WARNING, "Error accepting a client connection: %s (addr=%s laddr=%s)", connGetLastError(conn), getClientPeerId(c), getClientSockname(c)); freeClientAsync(c); return; } /* If the server is running in protected mode (the default) and there * is no password set, nor a specific interface is bound, we don't accept * requests from non loopback interfaces. Instead we try to explain the * user what to do to fix it if needed. */ if (server.protected_mode && DefaultUser->flags & USER_FLAG_NOPASS) { if (connIsLocal(conn) != 1) { char *err = "-DENIED Running in protected mode because protected " "mode is enabled and no password is set for the default user. " "In this mode connections are only accepted from the loopback interface. " "If you want to connect from external computers, you " "may adopt one of the following solutions: " "1) Just disable protected mode sending the command " "'CONFIG SET protected-mode no' from the loopback interface " "by connecting from the same host the server is " "running, however MAKE SURE it's not publicly accessible " "from internet if you do so. Use CONFIG REWRITE to make this " "change permanent. " "2) Alternatively you can just disable the protected mode by " "editing the configuration file, and setting the protected " "mode option to 'no', and then restarting the server. " "3) If you started the server manually just for testing, restart " "it with the '--protected-mode no' option. " "4) Set up an authentication password for the default user. " "NOTE: You only need to do one of the above things in order for " "the server to start accepting connections from the outside.\r\n"; if (connWrite(c->conn, err, strlen(err)) == -1) { /* Nothing to do, Just to avoid the warning... */ } server.stat_rejected_conn++; freeClientAsync(c); return; } } server.stat_numconnections++; moduleFireServerEvent(VALKEYMODULE_EVENT_CLIENT_CHANGE, VALKEYMODULE_SUBEVENT_CLIENT_CHANGE_CONNECTED, c); } void acceptCommonHandler(connection *conn, struct ClientFlags flags, char *ip) { client *c; UNUSED(ip); if (connGetState(conn) != CONN_STATE_ACCEPTING) { char addr[NET_ADDR_STR_LEN] = {0}; char laddr[NET_ADDR_STR_LEN] = {0}; connFormatAddr(conn, addr, sizeof(addr), 1); connFormatAddr(conn, laddr, sizeof(addr), 0); serverLog(LL_VERBOSE, "Accepted client connection in error state: %s (addr=%s laddr=%s)", connGetLastError(conn), addr, laddr); connClose(conn); return; } /* Limit the number of connections we take at the same time. * * Admission control will happen before a client is created and connAccept() * called, because we don't want to even start transport-level negotiation * if rejected. */ if (listLength(server.clients) + getClusterConnectionsCount() >= server.maxclients) { char *err; if (server.cluster_enabled) err = "-ERR max number of clients + cluster " "connections reached\r\n"; else err = "-ERR max number of clients reached\r\n"; /* That's a best effort error message, don't check write errors. * Note that for TLS connections, no handshake was done yet so nothing * is written and the connection will just drop. */ if (connWrite(conn, err, strlen(err)) == -1) { /* Nothing to do, Just to avoid the warning... */ } server.stat_rejected_conn++; connClose(conn); return; } /* Create connection and client */ if ((c = createClient(conn)) == NULL) { char addr[NET_ADDR_STR_LEN] = {0}; char laddr[NET_ADDR_STR_LEN] = {0}; connFormatAddr(conn, addr, sizeof(addr), 1); connFormatAddr(conn, laddr, sizeof(addr), 0); serverLog(LL_WARNING, "Error registering fd event for the new client connection: %s (addr=%s laddr=%s)", connGetLastError(conn), addr, laddr); connClose(conn); /* May be already closed, just ignore errors */ return; } /* Last chance to keep flags */ if (flags.unix_socket) c->flag.unix_socket = 1; /* Initiate accept. * * Note that connAccept() is free to do two things here: * 1. Call clientAcceptHandler() immediately; * 2. Schedule a future call to clientAcceptHandler(). * * Because of that, we must do nothing else afterwards. */ if (connAccept(conn, clientAcceptHandler) == C_ERR) { if (connGetState(conn) == CONN_STATE_ERROR) serverLog(LL_WARNING, "Error accepting a client connection: %s (addr=%s laddr=%s)", connGetLastError(conn), getClientPeerId(c), getClientSockname(c)); freeClient(connGetPrivateData(conn)); return; } } void freeClientOriginalArgv(client *c) { /* We didn't rewrite this client */ if (!c->original_argv) return; for (int j = 0; j < c->original_argc; j++) decrRefCount(c->original_argv[j]); zfree(c->original_argv); c->original_argv = NULL; c->original_argc = 0; } void freeClientArgv(client *c) { if (tryOffloadFreeArgvToIOThreads(c) == C_ERR) { for (int j = 0; j < c->argc; j++) decrRefCount(c->argv[j]); zfree(c->argv); } c->argc = 0; c->cmd = NULL; c->io_parsed_cmd = NULL; c->argv_len_sum = 0; c->argv_len = 0; c->argv = NULL; } /* Close all the replicas connections. This is useful in chained replication * when we resync with our own primary and want to force all our replicas to * resync with us as well. */ void disconnectReplicas(void) { listIter li; listNode *ln; listRewind(server.replicas, &li); while ((ln = listNext(&li))) { freeClient((client *)ln->value); } } /* Check if there is any other replica waiting dumping RDB finished expect me. * This function is useful to judge current dumping RDB can be used for full * synchronization or not. */ int anyOtherReplicaWaitRdb(client *except_me) { listIter li; listNode *ln; listRewind(server.replicas, &li); while ((ln = listNext(&li))) { client *replica = ln->value; if (replica != except_me && replica->repl_state == REPLICA_STATE_WAIT_BGSAVE_END) { return 1; } } return 0; } /* Remove the specified client from global lists where the client could * be referenced, not including the Pub/Sub channels. * This is used by freeClient() and replicationCachePrimary(). */ void unlinkClient(client *c) { listNode *ln; /* If this is marked as current client unset it. */ if (c->conn && server.current_client == c) server.current_client = NULL; /* Certain operations must be done only if the client has an active connection. * If the client was already unlinked or if it's a "fake client" the * conn is already set to NULL. */ if (c->conn) { /* Remove from the list of active clients. */ if (c->client_list_node) { uint64_t id = htonu64(c->id); raxRemove(server.clients_index, (unsigned char *)&id, sizeof(id), NULL); listDelNode(server.clients, c->client_list_node); c->client_list_node = NULL; } removeClientFromPendingCommandsBatch(c); /* Check if this is a replica waiting for diskless replication (rdb pipe), * in which case it needs to be cleaned from that list */ if (c->flag.replica && c->repl_state == REPLICA_STATE_WAIT_BGSAVE_END && server.rdb_pipe_conns) { int i; for (i = 0; i < server.rdb_pipe_numconns; i++) { if (server.rdb_pipe_conns[i] == c->conn) { rdbPipeWriteHandlerConnRemoved(c->conn); server.rdb_pipe_conns[i] = NULL; break; } } } /* Only use shutdown when the fork is active and we are the parent. */ if (server.child_type && !c->flag.repl_rdb_channel) { connShutdown(c->conn); } else if (c->flag.repl_rdb_channel) { shutdown(c->conn->fd, SHUT_RDWR); } connClose(c->conn); c->conn = NULL; } /* Remove from the list of pending writes if needed. */ if (c->flag.pending_write) { serverAssert(&c->clients_pending_write_node.next != NULL || &c->clients_pending_write_node.prev != NULL); if (c->io_write_state == CLIENT_IDLE) { listUnlinkNode(server.clients_pending_write, &c->clients_pending_write_node); } else { listUnlinkNode(server.clients_pending_io_write, &c->clients_pending_write_node); } c->flag.pending_write = 0; } /* Remove from the list of pending reads if needed. */ serverAssert(c->io_read_state != CLIENT_PENDING_IO && c->io_write_state != CLIENT_PENDING_IO); if (c->flag.pending_read) { listUnlinkNode(server.clients_pending_io_read, &c->pending_read_list_node); c->flag.pending_read = 0; } /* When client was just unblocked because of a blocking operation, * remove it from the list of unblocked clients. */ if (c->flag.unblocked) { ln = listSearchKey(server.unblocked_clients, c); serverAssert(ln != NULL); listDelNode(server.unblocked_clients, ln); c->flag.unblocked = 0; } /* Clear the tracking status. */ if (c->flag.tracking) disableTracking(c); } /* Clear the client state to resemble a newly connected client. */ void clearClientConnectionState(client *c) { listNode *ln; /* MONITOR clients are also marked with CLIENT_REPLICA, we need to * distinguish between the two. */ if (c->flag.monitor) { ln = listSearchKey(server.monitors, c); serverAssert(ln != NULL); listDelNode(server.monitors, ln); c->flag.monitor = 0; c->flag.replica = 0; } serverAssert(!(c->flag.replica || c->flag.primary)); if (c->flag.tracking) disableTracking(c); selectDb(c, 0); #ifdef LOG_REQ_RES c->resp = server.client_default_resp; #else c->resp = 2; #endif clientSetDefaultAuth(c); moduleNotifyUserChanged(c); discardTransaction(c); pubsubUnsubscribeAllChannels(c, 0); pubsubUnsubscribeShardAllChannels(c, 0); pubsubUnsubscribeAllPatterns(c, 0); unmarkClientAsPubSub(c); if (c->name) { decrRefCount(c->name); c->name = NULL; } /* Note: lib_name and lib_ver are not reset since they still * represent the client library behind the connection. */ /* Selectively clear state flags not covered above */ c->flag.asking = 0; c->flag.readonly = 0; c->flag.reply_off = 0; c->flag.reply_skip_next = 0; c->flag.no_touch = 0; c->flag.no_evict = 0; } void freeClient(client *c) { listNode *ln; /* If a client is protected, yet we need to free it right now, make sure * to at least use asynchronous freeing. */ if (c->flag.protected || c->flag.protected_rdb_channel) { freeClientAsync(c); return; } /* Wait for IO operations to be done before proceeding */ waitForClientIO(c); /* For connected clients, call the disconnection event of modules hooks. */ if (c->conn) { moduleFireServerEvent(VALKEYMODULE_EVENT_CLIENT_CHANGE, VALKEYMODULE_SUBEVENT_CLIENT_CHANGE_DISCONNECTED, c); } /* Notify module system that this client auth status changed. */ moduleNotifyUserChanged(c); /* Free the RedisModuleBlockedClient held onto for reprocessing if not already freed. */ zfree(c->module_blocked_client); /* If this client was scheduled for async freeing we need to remove it * from the queue. Note that we need to do this here, because later * we may call replicationCachePrimary() and the client should already * be removed from the list of clients to free. */ if (c->flag.close_asap) { ln = listSearchKey(server.clients_to_close, c); serverAssert(ln != NULL); listDelNode(server.clients_to_close, ln); } /* If it is our primary that's being disconnected we should make sure * to cache the state to try a partial resynchronization later. * * Note that before doing this we make sure that the client is not in * some unexpected state, by checking its flags. */ if (server.primary && c->flag.primary) { serverLog(LL_NOTICE, "Connection with primary lost."); if (!c->flag.dont_cache_primary && !(c->flag.protocol_error || c->flag.blocked)) { c->flag.close_asap = 0; c->flag.close_after_reply = 0; replicationCachePrimary(c); return; } } /* Log link disconnection with replica */ if (getClientType(c) == CLIENT_TYPE_REPLICA) { serverLog(LL_NOTICE, c->flag.repl_rdb_channel ? "Replica %s rdb channel disconnected." : "Connection with replica %s lost.", replicationGetReplicaName(c)); } /* Free the query buffer */ if (c->querybuf && c->querybuf == thread_shared_qb) { sdsclear(c->querybuf); } else { sdsfree(c->querybuf); } c->querybuf = NULL; /* Deallocate structures used to block on blocking ops. */ /* If there is any in-flight command, we don't record their duration. */ c->duration = 0; if (c->flag.blocked) unblockClient(c, 1); dictRelease(c->bstate.keys); /* UNWATCH all the keys */ unwatchAllKeys(c); listRelease(c->watched_keys); /* Unsubscribe from all the pubsub channels */ pubsubUnsubscribeAllChannels(c, 0); pubsubUnsubscribeShardAllChannels(c, 0); pubsubUnsubscribeAllPatterns(c, 0); unmarkClientAsPubSub(c); dictRelease(c->pubsub_channels); dictRelease(c->pubsub_patterns); dictRelease(c->pubsubshard_channels); /* Free data structures. */ listRelease(c->reply); zfree(c->buf); freeReplicaReferencedReplBuffer(c); freeClientArgv(c); freeClientOriginalArgv(c); if (c->deferred_reply_errors) listRelease(c->deferred_reply_errors); #ifdef LOG_REQ_RES reqresReset(c, 1); #endif /* Remove the contribution that this client gave to our * incrementally computed memory usage. */ if (c->conn) server.stat_clients_type_memory[c->last_memory_type] -= c->last_memory_usage; /* Unlink the client: this will close the socket, remove the I/O * handlers, and remove references of the client from different * places where active clients may be referenced. */ unlinkClient(c); /* Primary/replica cleanup Case 1: * we lost the connection with a replica. */ if (c->flag.replica) { /* If there is no any other replica waiting dumping RDB finished, the * current child process need not continue to dump RDB, then we kill it. * So child process won't use more memory, and we also can fork a new * child process asap to dump rdb for next full synchronization or bgsave. * But we also need to check if users enable 'save' RDB, if enable, we * should not remove directly since that means RDB is important for users * to keep data safe and we may delay configured 'save' for full sync. */ if (server.saveparamslen == 0 && c->repl_state == REPLICA_STATE_WAIT_BGSAVE_END && server.child_type == CHILD_TYPE_RDB && server.rdb_child_type == RDB_CHILD_TYPE_DISK && anyOtherReplicaWaitRdb(c) == 0) { killRDBChild(); } if (c->repl_state == REPLICA_STATE_SEND_BULK) { if (c->repldbfd != -1) close(c->repldbfd); if (c->replpreamble) sdsfree(c->replpreamble); } list *l = (c->flag.monitor) ? server.monitors : server.replicas; ln = listSearchKey(l, c); serverAssert(ln != NULL); listDelNode(l, ln); /* We need to remember the time when we started to have zero * attached replicas, as after some time we'll free the replication * backlog. */ if (getClientType(c) == CLIENT_TYPE_REPLICA && listLength(server.replicas) == 0) server.repl_no_replicas_since = server.unixtime; refreshGoodReplicasCount(); /* Fire the replica change modules event. */ if (c->repl_state == REPLICA_STATE_ONLINE) moduleFireServerEvent(VALKEYMODULE_EVENT_REPLICA_CHANGE, VALKEYMODULE_SUBEVENT_REPLICA_CHANGE_OFFLINE, NULL); } /* Primary/replica cleanup Case 2: * we lost the connection with the primary. */ if (c->flag.primary) replicationHandlePrimaryDisconnection(); /* Remove client from memory usage buckets */ if (c->mem_usage_bucket) { c->mem_usage_bucket->mem_usage_sum -= c->last_memory_usage; listDelNode(c->mem_usage_bucket->clients, c->mem_usage_bucket_node); } /* Release other dynamically allocated client structure fields, * and finally release the client structure itself. */ if (c->name) decrRefCount(c->name); if (c->lib_name) decrRefCount(c->lib_name); if (c->lib_ver) decrRefCount(c->lib_ver); freeClientMultiState(c); sdsfree(c->peerid); sdsfree(c->sockname); sdsfree(c->replica_addr); zfree(c); } /* Schedule a client to free it at a safe time in the beforeSleep() function. * This function is useful when we need to terminate a client but we are in * a context where calling freeClient() is not possible, because the client * should be valid for the continuation of the flow of the program. */ void freeClientAsync(client *c) { if (c->flag.close_asap || c->flag.script) return; c->flag.close_asap = 1; debugServerAssertWithInfo(c, NULL, listSearchKey(server.clients_to_close, c) == NULL); listAddNodeTail(server.clients_to_close, c); } /* Log errors for invalid use and free the client in async way. * We will add additional information about the client to the message. */ void logInvalidUseAndFreeClientAsync(client *c, const char *fmt, ...) { va_list ap; va_start(ap, fmt); sds info = sdscatvprintf(sdsempty(), fmt, ap); va_end(ap); sds client = catClientInfoString(sdsempty(), c, server.hide_user_data_from_log); serverLog(LL_WARNING, "%s, disconnecting it: %s", info, client); sdsfree(info); sdsfree(client); freeClientAsync(c); } /* Resets the shared query buffer used by the given client. * If any data remained in the buffer, the client will take ownership of the buffer * and a new empty buffer will be allocated for the shared buffer. */ void resetSharedQueryBuf(client *c) { serverAssert(c->querybuf == thread_shared_qb); size_t remaining = sdslen(c->querybuf) - c->qb_pos; if (remaining > 0) { /* Let the client take ownership of the shared buffer. */ initSharedQueryBuf(); return; } c->querybuf = NULL; sdsclear(thread_shared_qb); c->qb_pos = 0; } /* Trims the client query buffer to the current position. */ void trimClientQueryBuffer(client *c) { if (c->querybuf == thread_shared_qb) { resetSharedQueryBuf(c); } if (c->querybuf == NULL) { return; } serverAssert(c->qb_pos <= sdslen(c->querybuf)); if (c->qb_pos > 0) { sdsrange(c->querybuf, c->qb_pos, -1); c->qb_pos = 0; } } /* Perform processing of the client before moving on to processing the next client. * This is useful for performing operations that affect the global state but can't * wait until we're done with all clients. In other words, it can't wait until beforeSleep(). * With IO threads enabled, this function offloads the write to the IO threads if possible. */ void beforeNextClient(client *c) { /* Notice, this code is also called from 'processUnblockedClients'. * But in case of a module blocked client (see RM_Call 'K' flag) we do not reach this code path. * So whenever we change the code here we need to consider if we need this change on module * blocked client as well */ /* Trim the query buffer to the current position. */ if (c->flag.primary) { /* If the client is a primary, trim the querybuf to repl_applied, * since primary client is very special, its querybuf not only * used to parse command, but also proxy to sub-replicas. * * Here are some scenarios we cannot trim to qb_pos: * 1. we don't receive complete command from primary * 2. primary client blocked cause of client pause * 3. io threads operate read, primary client flagged with CLIENT_PENDING_COMMAND * * In these scenarios, qb_pos points to the part of the current command * or the beginning of next command, and the current command is not applied yet, * so the repl_applied is not equal to qb_pos. */ if (c->repl_applied) { sdsrange(c->querybuf, c->repl_applied, -1); c->qb_pos -= c->repl_applied; c->repl_applied = 0; } } else { trimClientQueryBuffer(c); } /* Handle async frees */ /* Note: this doesn't make the server.clients_to_close list redundant because of * cases where we want an async free of a client other than myself. For example * in ACL modifications we disconnect clients authenticated to non-existent * users (see ACL LOAD). */ if (c->flag.close_asap) { freeClient(c); return; } updateClientMemUsageAndBucket(c); /* If IO threads are enabled try to write immediately the reply instead of waiting to beforeSleep, * unless aof_fsync is set to always in which case we need to wait for beforeSleep after writing the aof buffer. */ if (server.aof_fsync != AOF_FSYNC_ALWAYS) { trySendWriteToIOThreads(c); } } /* Free the clients marked as CLOSE_ASAP, return the number of clients * freed. */ int freeClientsInAsyncFreeQueue(void) { int freed = 0; listIter li; listNode *ln; listRewind(server.clients_to_close, &li); while ((ln = listNext(&li)) != NULL) { client *c = listNodeValue(ln); if (c->flag.protected_rdb_channel) { /* Check if it's safe to remove RDB connection protection during synchronization * The primary gives a grace period before freeing this client because * it serves as a reference to the first required replication data block for * this replica */ if (!c->rdb_client_disconnect_time) { if (c->conn) connSetReadHandler(c->conn, NULL); c->rdb_client_disconnect_time = server.unixtime; serverLog(LL_VERBOSE, "Postpone RDB client id=%llu (%s) free for %d seconds", (unsigned long long)c->id, replicationGetReplicaName(c), server.wait_before_rdb_client_free); } if (server.unixtime - c->rdb_client_disconnect_time <= server.wait_before_rdb_client_free) continue; serverLog(LL_NOTICE, "Replica main channel failed to establish PSYNC within the grace period (%ld seconds). " "Freeing RDB client %llu.", (long int)(server.unixtime - c->rdb_client_disconnect_time), (unsigned long long)c->id); c->flag.protected_rdb_channel = 0; } if (c->flag.protected) continue; c->flag.close_asap = 0; freeClient(c); listDelNode(server.clients_to_close, ln); freed++; } return freed; } /* Return a client by ID, or NULL if the client ID is not in the set * of registered clients. Note that "fake clients", created with -1 as FD, * are not registered clients. */ client *lookupClientByID(uint64_t id) { id = htonu64(id); void *c = NULL; raxFind(server.clients_index, (unsigned char *)&id, sizeof(id), &c); return c; } void writeToReplica(client *c) { /* Can be called from main-thread only as replica write offload is not supported yet */ serverAssert(inMainThread()); int nwritten = 0; serverAssert(c->bufpos == 0 && listLength(c->reply) == 0); while (clientHasPendingReplies(c)) { replBufBlock *o = listNodeValue(c->ref_repl_buf_node); serverAssert(o->used >= c->ref_block_pos); /* Send current block if it is not fully sent. */ if (o->used > c->ref_block_pos) { nwritten = connWrite(c->conn, o->buf + c->ref_block_pos, o->used - c->ref_block_pos); if (nwritten <= 0) { c->write_flags |= WRITE_FLAGS_WRITE_ERROR; return; } c->nwritten += nwritten; c->ref_block_pos += nwritten; } /* If we fully sent the object on head, go to the next one. */ listNode *next = listNextNode(c->ref_repl_buf_node); if (next && c->ref_block_pos == o->used) { o->refcount--; ((replBufBlock *)(listNodeValue(next)))->refcount++; c->ref_repl_buf_node = next; c->ref_block_pos = 0; incrementalTrimReplicationBacklog(REPL_BACKLOG_TRIM_BLOCKS_PER_CALL); } } } /* This function should be called from _writeToClient when the reply list is not empty, * it gathers the scattered buffers from reply list and sends them away with connWritev. * If we write successfully, it returns C_OK, otherwise, C_ERR is returned. * Sets the c->nwritten to the number of bytes the server wrote to the client. * Can be called from the main thread or an I/O thread */ static int writevToClient(client *c) { int iovcnt = 0; int iovmax = min(IOV_MAX, c->conn->iovcnt); struct iovec iov_arr[iovmax]; struct iovec *iov = iov_arr; ssize_t bufpos, iov_bytes_len = 0; listNode *lastblock; if (inMainThread()) { lastblock = listLast(c->reply); bufpos = c->bufpos; } else { lastblock = c->io_last_reply_block; bufpos = lastblock ? (size_t)c->bufpos : c->io_last_bufpos; } /* If the static reply buffer is not empty, * add it to the iov array for writev() as well. */ if (bufpos > 0) { iov[iovcnt].iov_base = c->buf + c->sentlen; iov[iovcnt].iov_len = bufpos - c->sentlen; iov_bytes_len += iov[iovcnt++].iov_len; } /* The first node of reply list might be incomplete from the last call, * thus it needs to be calibrated to get the actual data address and length. */ size_t sentlen = bufpos > 0 ? 0 : c->sentlen; listIter iter; listNode *next; clientReplyBlock *o; size_t used; listRewind(c->reply, &iter); while ((next = listNext(&iter)) && iovcnt < iovmax && iov_bytes_len < NET_MAX_WRITES_PER_EVENT) { o = listNodeValue(next); used = o->used; /* Use c->io_last_bufpos as the currently used portion of the block. * We use io_last_bufpos instead of o->used to ensure that we only access data guaranteed to be visible to the * current thread. Using o->used, which may have been updated by the main thread, could lead to accessing data * that may not yet be visible to the current thread*/ if (!inMainThread() && next == lastblock) used = c->io_last_bufpos; if (used == 0) { /* empty node, skip over it. */ if (next == lastblock) break; sentlen = 0; continue; } iov[iovcnt].iov_base = o->buf + sentlen; iov[iovcnt].iov_len = used - sentlen; iov_bytes_len += iov[iovcnt++].iov_len; sentlen = 0; if (next == lastblock) break; } serverAssert(iovcnt != 0); ssize_t totwritten = 0; while (1) { int nwritten = connWritev(c->conn, iov, iovcnt); if (nwritten <= 0) { c->write_flags |= WRITE_FLAGS_WRITE_ERROR; totwritten = totwritten > 0 ? totwritten : nwritten; break; } totwritten += nwritten; if (totwritten == iov_bytes_len) break; if (totwritten > NET_MAX_WRITES_PER_EVENT) { /* Note that we avoid to send more than NET_MAX_WRITES_PER_EVENT * bytes, Since it's a good idea to serve * other clients as well, even if a very large request comes from * super fast link that is always able to accept data (in real world * scenario think about 'KEYS *' against the loopback interface). * * However if we are over the maxmemory limit we ignore that and * just deliver as much data as it is possible to deliver. */ int ignore_max_write_limit = server.maxmemory > 0 && zmalloc_used_memory() > server.maxmemory; if (!ignore_max_write_limit) { break; } } /* proceed to the unwritten blocks */ while (nwritten > 0) { if ((size_t)nwritten < iov[0].iov_len) { iov[0].iov_base = (char *)iov[0].iov_base + nwritten; iov[0].iov_len -= nwritten; break; } nwritten -= iov[0].iov_len; iov++; iovcnt--; } } c->nwritten = totwritten; return totwritten > 0 ? C_OK : C_ERR; } /* This function does actual writing output buffers to non-replica client, it is called by writeToClient. * If we write successfully, it returns C_OK, otherwise, C_ERR is returned, * and 'c->nwritten' is set to the number of bytes the server wrote to the client. */ int _writeToClient(client *c) { listNode *lastblock; size_t bufpos; if (inMainThread()) { /* In the main thread, access bufpos and lastblock directly */ lastblock = listLast(c->reply); bufpos = (size_t)c->bufpos; } else { /* If there is a last block, use bufpos directly; otherwise, use io_last_bufpos */ bufpos = c->io_last_reply_block ? (size_t)c->bufpos : c->io_last_bufpos; lastblock = c->io_last_reply_block; } /* If the reply list is not empty, use writev to save system calls and TCP packets */ if (lastblock) return writevToClient(c); ssize_t bytes_to_write = bufpos - c->sentlen; ssize_t tot_written = 0; while (tot_written < bytes_to_write) { int nwritten = connWrite(c->conn, c->buf + c->sentlen + tot_written, bytes_to_write - tot_written); if (nwritten <= 0) { c->write_flags |= WRITE_FLAGS_WRITE_ERROR; tot_written = tot_written > 0 ? tot_written : nwritten; break; } tot_written += nwritten; } c->nwritten = tot_written; return tot_written > 0 ? C_OK : C_ERR; } static void _postWriteToClient(client *c) { if (c->nwritten <= 0) return; listIter iter; listNode *next; clientReplyBlock *o; server.stat_net_output_bytes += c->nwritten; /* Locate the new node which has leftover data and * release all nodes in front of it. */ ssize_t remaining = c->nwritten; if (c->bufpos > 0) { /* Deal with static reply buffer first. */ int buf_len = c->bufpos - c->sentlen; c->sentlen += c->nwritten; /* If the buffer was sent, set bufpos to zero to continue with * the remainder of the reply. */ if (c->nwritten >= buf_len) { c->bufpos = 0; c->sentlen = 0; } remaining -= buf_len; } listRewind(c->reply, &iter); while (remaining > 0) { next = listNext(&iter); o = listNodeValue(next); if (remaining < (ssize_t)(o->used - c->sentlen)) { c->sentlen += remaining; break; } remaining -= (ssize_t)(o->used - c->sentlen); c->reply_bytes -= o->size; listDelNode(c->reply, next); c->sentlen = 0; } } /* Updates the client's memory usage and bucket and server stats after writing. * If a write handler is installed , it will attempt to clear the write event. * If the client is no longer valid, it will return C_ERR, otherwise C_OK. */ int postWriteToClient(client *c) { c->io_last_reply_block = NULL; c->io_last_bufpos = 0; /* Update total number of writes on server */ server.stat_total_writes_processed++; if (getClientType(c) != CLIENT_TYPE_REPLICA) { _postWriteToClient(c); } if (c->write_flags & WRITE_FLAGS_WRITE_ERROR) { if (connGetState(c->conn) != CONN_STATE_CONNECTED) { serverLog(LL_VERBOSE, "Error writing to client: %s", connGetLastError(c->conn)); freeClientAsync(c); return C_ERR; } } if (c->nwritten > 0) { c->net_output_bytes += c->nwritten; /* For clients representing primaries we don't count sending data * as an interaction, since we always send REPLCONF ACK commands * that take some time to just fill the socket output buffer. * We just rely on data / pings received for timeout detection. */ if (!c->flag.primary) c->last_interaction = server.unixtime; } if (!clientHasPendingReplies(c)) { c->sentlen = 0; if (connHasWriteHandler(c->conn)) { connSetWriteHandler(c->conn, NULL); } /* Close connection after entire reply has been sent. */ if (c->flag.close_after_reply) { freeClientAsync(c); return C_ERR; } } /* Update client's memory usage after writing.*/ updateClientMemUsageAndBucket(c); return C_OK; } /* Write data in output buffers to client. Return C_OK if the client * is still valid after the call, C_ERR if it was freed because of some * error. * * This function is called by main-thread only */ int writeToClient(client *c) { if (c->io_write_state != CLIENT_IDLE || c->io_read_state != CLIENT_IDLE) return C_OK; c->nwritten = 0; c->write_flags = 0; if (getClientType(c) == CLIENT_TYPE_REPLICA) { writeToReplica(c); } else { _writeToClient(c); } return postWriteToClient(c); } /* Write event handler. Just send data to the client. */ void sendReplyToClient(connection *conn) { client *c = connGetPrivateData(conn); if (trySendWriteToIOThreads(c) == C_OK) return; writeToClient(c); } void handleQbLimitReached(client *c) { sds ci = catClientInfoString(sdsempty(), c, server.hide_user_data_from_log), bytes = sdsempty(); bytes = sdscatrepr(bytes, c->querybuf, 64); serverLog(LL_WARNING, "Closing client that reached max query buffer length: %s (qbuf initial bytes: %s)", ci, bytes); sdsfree(ci); sdsfree(bytes); freeClientAsync(c); server.stat_client_qbuf_limit_disconnections++; } /* Handle read errors and update statistics. * * Called only from the main thread. * If the read was done in an I/O thread, this function is invoked after the * read job has completed, in the main thread context. * * Returns: * - C_OK if the querybuf can be further processed. * - C_ERR if not. */ int handleReadResult(client *c) { serverAssert(inMainThread()); server.stat_total_reads_processed++; if (c->nread <= 0) { if (c->nread == -1) { if (connGetState(c->conn) != CONN_STATE_CONNECTED) { serverLog(LL_VERBOSE, "Reading from client: %s", connGetLastError(c->conn)); freeClientAsync(c); } } else if (c->nread == 0) { if (server.verbosity <= LL_VERBOSE) { sds info = catClientInfoString(sdsempty(), c, server.hide_user_data_from_log); serverLog(LL_VERBOSE, "Client closed connection %s", info); sdsfree(info); } freeClientAsync(c); } return C_ERR; } c->last_interaction = server.unixtime; c->net_input_bytes += c->nread; if (c->flag.primary) { c->read_reploff += c->nread; server.stat_net_repl_input_bytes += c->nread; } else { server.stat_net_input_bytes += c->nread; } /* Handle QB limit */ if (c->read_flags & READ_FLAGS_QB_LIMIT_REACHED) { handleQbLimitReached(c); return C_ERR; } return C_OK; } void handleParseError(client *c) { int flags = c->read_flags; if (flags & READ_FLAGS_ERROR_BIG_INLINE_REQUEST) { addReplyError(c, "Protocol error: too big inline request"); setProtocolError("too big inline request", c); } else if (flags & READ_FLAGS_ERROR_BIG_MULTIBULK) { addReplyError(c, "Protocol error: too big mbulk count string"); setProtocolError("too big mbulk count string", c); } else if (flags & READ_FLAGS_ERROR_INVALID_MULTIBULK_LEN) { addReplyError(c, "Protocol error: invalid multibulk length"); setProtocolError("invalid mbulk count", c); } else if (flags & READ_FLAGS_ERROR_UNAUTHENTICATED_MULTIBULK_LEN) { addReplyError(c, "Protocol error: unauthenticated multibulk length"); setProtocolError("unauth mbulk count", c); } else if (flags & READ_FLAGS_ERROR_UNAUTHENTICATED_BULK_LEN) { addReplyError(c, "Protocol error: unauthenticated bulk length"); setProtocolError("unauth bulk length", c); } else if (flags & READ_FLAGS_ERROR_BIG_BULK_COUNT) { addReplyError(c, "Protocol error: too big bulk count string"); setProtocolError("too big bulk count string", c); } else if (flags & READ_FLAGS_ERROR_MBULK_UNEXPECTED_CHARACTER) { addReplyErrorFormat(c, "Protocol error: expected '$', got '%c'", c->querybuf[c->qb_pos]); setProtocolError("expected $ but got something else", c); } else if (flags & READ_FLAGS_ERROR_MBULK_INVALID_BULK_LEN) { addReplyError(c, "Protocol error: invalid bulk length"); setProtocolError("invalid bulk length", c); } else if (flags & READ_FLAGS_ERROR_UNBALANCED_QUOTES) { addReplyError(c, "Protocol error: unbalanced quotes in request"); setProtocolError("unbalanced quotes in inline request", c); } else if (flags & READ_FLAGS_ERROR_UNEXPECTED_INLINE_FROM_PRIMARY) { serverLog(LL_WARNING, "WARNING: Receiving inline protocol from primary, primary stream corruption? Closing the " "primary connection and discarding the cached primary."); setProtocolError("Master using the inline protocol. Desync?", c); } else { serverAssertWithInfo(c, NULL, "Unknown parsing error"); } } int isParsingError(client *c) { return c->read_flags & (READ_FLAGS_ERROR_BIG_INLINE_REQUEST | READ_FLAGS_ERROR_BIG_MULTIBULK | READ_FLAGS_ERROR_INVALID_MULTIBULK_LEN | READ_FLAGS_ERROR_UNAUTHENTICATED_MULTIBULK_LEN | READ_FLAGS_ERROR_UNAUTHENTICATED_BULK_LEN | READ_FLAGS_ERROR_MBULK_INVALID_BULK_LEN | READ_FLAGS_ERROR_BIG_BULK_COUNT | READ_FLAGS_ERROR_MBULK_UNEXPECTED_CHARACTER | READ_FLAGS_ERROR_UNEXPECTED_INLINE_FROM_PRIMARY | READ_FLAGS_ERROR_UNBALANCED_QUOTES); } /* This function is called after the query-buffer was parsed. * It is used to handle parsing errors and to update the client state. * The function returns C_OK if a command can be executed, otherwise C_ERR. */ parseResult handleParseResults(client *c) { if (isParsingError(c)) { handleParseError(c); return PARSE_ERR; } if (c->read_flags & READ_FLAGS_INLINE_ZERO_QUERY_LEN && getClientType(c) == CLIENT_TYPE_REPLICA) { c->repl_ack_time = server.unixtime; } if (c->read_flags & READ_FLAGS_INLINE_ZERO_QUERY_LEN) { /* in case the client's query was an empty line we will ignore it and proceed to process the rest of the buffer * if any */ resetClient(c); return PARSE_OK; } if (c->read_flags & READ_FLAGS_PARSING_NEGATIVE_MBULK_LEN) { /* Multibulk processing could see a <= 0 length. */ resetClient(c); return PARSE_OK; } if (c->read_flags & READ_FLAGS_PARSING_COMPLETED) { return PARSE_OK; } else { return PARSE_NEEDMORE; } } /* Process the completion of an IO write operation for a client. * This function handles various post-write tasks, including updating client state, * allow_async_writes - A flag indicating whether I/O threads can handle pending writes for this client. * returns 1 if processing completed successfully, 0 if processing is skipped. */ int processClientIOWriteDone(client *c, int allow_async_writes) { /* memory barrier acquire to get the latest client state */ atomic_thread_fence(memory_order_acquire); /* If a client is protected, don't proceed to check the write results as it may trigger conn close. */ if (c->flag.protected) return 0; listUnlinkNode(server.clients_pending_io_write, &c->clients_pending_write_node); c->flag.pending_write = 0; c->io_write_state = CLIENT_IDLE; /* Don't post-process-writes to clients that are going to be closed anyway. */ if (c->flag.close_asap) return 0; /* Update processed count on server */ server.stat_io_writes_processed += 1; connSetPostponeUpdateState(c->conn, 0); connUpdateState(c->conn); if (postWriteToClient(c) == C_ERR) { return 1; } if (clientHasPendingReplies(c)) { if (c->write_flags & WRITE_FLAGS_WRITE_ERROR) { /* Install the write handler if there are pending writes in some of the clients as a result of not being * able to write everything in one go. */ installClientWriteHandler(c); } else { /* If we can send the client to the I/O thread, let it handle the write. */ if (allow_async_writes && trySendWriteToIOThreads(c) == C_OK) return 1; /* Try again in the next eventloop */ putClientInPendingWriteQueue(c); } } return 1; } /* This function handles the post-processing of I/O write operations that have been * completed for clients. It iterates through the list of clients with pending I/O * writes and performs necessary actions based on their current state. * * Returns The number of clients processed during this function call. */ int processIOThreadsWriteDone(void) { if (listLength(server.clients_pending_io_write) == 0) return 0; int processed = 0; listNode *ln; listNode *next = listFirst(server.clients_pending_io_write); while (next) { ln = next; next = listNextNode(ln); client *c = listNodeValue(ln); /* Client is still waiting for a pending I/O - skip it */ if (c->io_write_state == CLIENT_PENDING_IO || c->io_read_state == CLIENT_PENDING_IO) continue; processed += processClientIOWriteDone(c, 1); } return processed; } /* This function is called just before entering the event loop, in the hope * we can just write the replies to the client output buffer without any * need to use a syscall in order to install the writable event handler, * get it called, and so forth. */ int handleClientsWithPendingWrites(void) { int processed = 0; int pending_writes = listLength(server.clients_pending_write); if (pending_writes == 0) return processed; /* Return ASAP if there are no clients. */ /* Adjust the number of I/O threads based on the number of pending writes this is required in case pending_writes > * poll_events (for example in pubsub) */ adjustIOThreadsByEventLoad(pending_writes, 1); listIter li; listNode *ln; listRewind(server.clients_pending_write, &li); while ((ln = listNext(&li))) { client *c = listNodeValue(ln); c->flag.pending_write = 0; listUnlinkNode(server.clients_pending_write, ln); /* If a client is protected, don't do anything, * that may trigger write error or recreate handler. */ if (c->flag.protected) continue; /* Don't write to clients that are going to be closed anyway. */ if (c->flag.close_asap) continue; if (!clientHasPendingReplies(c)) continue; /* If we can send the client to the I/O thread, let it handle the write. */ if (trySendWriteToIOThreads(c) == C_OK) continue; /* We can't write to the client while IO operation is in progress. */ if (c->io_write_state != CLIENT_IDLE || c->io_read_state != CLIENT_IDLE) continue; processed++; /* Try to write buffers to the client socket. */ if (writeToClient(c) == C_ERR) continue; /* If after the synchronous writes above we still have data to * output to the client, we need to install the writable handler. */ if (clientHasPendingReplies(c)) { installClientWriteHandler(c); } } return processed; } /* resetClient prepare the client to process the next command */ void resetClient(client *c) { serverCommandProc *prevcmd = c->cmd ? c->cmd->proc : NULL; freeClientArgv(c); c->cur_script = NULL; c->reqtype = 0; c->multibulklen = 0; c->net_input_bytes_curr_cmd = 0; c->bulklen = -1; c->slot = -1; c->flag.executing_command = 0; c->flag.replication_done = 0; c->net_output_bytes_curr_cmd = 0; /* Make sure the duration has been recorded to some command. */ serverAssert(c->duration == 0); #ifdef LOG_REQ_RES reqresReset(c, 1); #endif if (c->deferred_reply_errors) listRelease(c->deferred_reply_errors); c->deferred_reply_errors = NULL; /* We clear the ASKING flag as well if we are not inside a MULTI, and * if what we just executed is not the ASKING command itself. */ if (!c->flag.multi && prevcmd != askingCommand) c->flag.asking = 0; /* We do the same for the CACHING command as well. It also affects * the next command or transaction executed, in a way very similar * to ASKING. */ if (!c->flag.multi && prevcmd != clientCommand) c->flag.tracking_caching = 0; /* Remove the CLIENT_REPLY_SKIP flag if any so that the reply * to the next command will be sent, but set the flag if the command * we just processed was "CLIENT REPLY SKIP". */ c->flag.reply_skip = 0; if (c->flag.reply_skip_next) { c->flag.reply_skip = 1; c->flag.reply_skip_next = 0; } } /* Initializes the shared query buffer to a new sds with the default capacity. * Need to ensure the initlen is not less than readlen in readToQueryBuf. */ void initSharedQueryBuf(void) { thread_shared_qb = sdsnewlen(NULL, PROTO_IOBUF_LEN); sdsclear(thread_shared_qb); } void freeSharedQueryBuf(void) { sdsfree(thread_shared_qb); thread_shared_qb = NULL; } /* This function is used when we want to re-enter the event loop but there * is the risk that the client we are dealing with will be freed in some * way. This happens for instance in: * * * DEBUG RELOAD and similar. * * When a Lua script is in -BUSY state. * * A cluster replica executing CLUSTER SETSLOT during slot migration. * * So the function will protect the client by doing two things: * * 1) It removes the file events. This way it is not possible that an * error is signaled on the socket, freeing the client. * 2) Moreover it makes sure that if the client is freed in a different code * path, it is not really released, but only marked for later release. */ void protectClient(client *c) { c->flag.protected = 1; if (c->conn) { connSetReadHandler(c->conn, NULL); connSetWriteHandler(c->conn, NULL); } } /* This will undo the client protection done by protectClient() */ void unprotectClient(client *c) { if (c->flag.protected) { c->flag.protected = 0; if (c->conn) { connSetReadHandler(c->conn, readQueryFromClient); if (clientHasPendingReplies(c)) putClientInPendingWriteQueue(c); } } } /* Like processMultibulkBuffer(), but for the inline protocol instead of RESP, * this function consumes the client query buffer and creates a command ready * to be executed inside the client structure. * Sets the client read_flags to indicate the parsing outcome. */ void processInlineBuffer(client *c) { char *newline; int argc, j, linefeed_chars = 1; sds *argv, aux; size_t querylen; int is_primary = c->read_flags & READ_FLAGS_PRIMARY; /* Search for end of line */ newline = strchr(c->querybuf + c->qb_pos, '\n'); /* Nothing to do without a \r\n */ if (newline == NULL) { if (sdslen(c->querybuf) - c->qb_pos > PROTO_INLINE_MAX_SIZE) { c->read_flags |= READ_FLAGS_ERROR_BIG_INLINE_REQUEST; } return; } /* Handle the \r\n case. */ if (newline != c->querybuf + c->qb_pos && *(newline - 1) == '\r') newline--, linefeed_chars++; /* Split the input buffer up to the \r\n */ querylen = newline - (c->querybuf + c->qb_pos); aux = sdsnewlen(c->querybuf + c->qb_pos, querylen); argv = sdssplitargs(aux, &argc); sdsfree(aux); if (argv == NULL) { c->read_flags |= READ_FLAGS_ERROR_UNBALANCED_QUOTES; return; } if (querylen == 0) { c->read_flags |= READ_FLAGS_INLINE_ZERO_QUERY_LEN; } /* Primaries should never send us inline protocol to run actual * commands. If this happens, it is likely due to a bug in the server where * we got some desynchronization in the protocol, for example * because of a PSYNC gone bad. * * However there is an exception: primaries may send us just a newline * to keep the connection active. */ if (querylen != 0 && is_primary) { sdsfreesplitres(argv, argc); c->read_flags |= READ_FLAGS_ERROR_UNEXPECTED_INLINE_FROM_PRIMARY; return; } /* Move querybuffer position to the next query in the buffer. */ c->qb_pos += querylen + linefeed_chars; /* Setup argv array on client structure */ if (argc) { if (c->argv) zfree(c->argv); c->argv_len = argc; c->argv = zmalloc(sizeof(robj *) * c->argv_len); c->argv_len_sum = 0; } /* Create an Object for all arguments. */ for (c->argc = 0, j = 0; j < argc; j++) { c->argv[c->argc] = createObject(OBJ_STRING, argv[j]); c->argc++; c->argv_len_sum += sdslen(argv[j]); } zfree(argv); /* Per-slot network bytes-in calculation. * * We calculate and store the current command's ingress bytes under * c->net_input_bytes_curr_cmd, for which its per-slot aggregation is deferred * until c->slot is parsed later within processCommand(). * * Calculation: For inline buffer, every whitespace is of length 1, * with the exception of the trailing '\r\n' being length 2. * * For example; * Command) SET key value * Inline) SET key value\r\n * */ c->net_input_bytes_curr_cmd = (c->argv_len_sum + (c->argc - 1) + 2); c->read_flags |= READ_FLAGS_PARSING_COMPLETED; } /* Helper function. Record protocol error details in server log, * and set the client as CLIENT_CLOSE_AFTER_REPLY and * CLIENT_PROTOCOL_ERROR. */ #define PROTO_DUMP_LEN 128 static void setProtocolError(const char *errstr, client *c) { if (server.verbosity <= LL_VERBOSE || c->flag.primary) { sds client = catClientInfoString(sdsempty(), c, server.hide_user_data_from_log); /* Sample some protocol to given an idea about what was inside. */ char buf[256]; buf[0] = '\0'; if (c->querybuf && sdslen(c->querybuf) - c->qb_pos < PROTO_DUMP_LEN) { snprintf(buf, sizeof(buf), "Query buffer during protocol error: '%s'", c->querybuf + c->qb_pos); } else if (c->querybuf) { snprintf(buf, sizeof(buf), "Query buffer during protocol error: '%.*s' (... more %zu bytes ...) '%.*s'", PROTO_DUMP_LEN / 2, c->querybuf + c->qb_pos, sdslen(c->querybuf) - c->qb_pos - PROTO_DUMP_LEN, PROTO_DUMP_LEN / 2, c->querybuf + sdslen(c->querybuf) - PROTO_DUMP_LEN / 2); } /* Remove non printable chars. */ char *p = buf; while (*p != '\0') { if (!isprint(*p)) *p = '.'; p++; } /* Log all the client and protocol info. */ int loglevel = (c->flag.primary) ? LL_WARNING : LL_VERBOSE; serverLog(loglevel, "Protocol error (%s) from client: %s. %s", errstr, client, buf); sdsfree(client); } c->flag.close_after_reply = 1; c->flag.protocol_error = 1; } /* Process the query buffer for client 'c', setting up the client argument * vector for command execution. * Sets the client's read_flags to indicate the parsing outcome. * * This function is called if processInputBuffer() detects that the next * command is in RESP format, so the first byte in the command is found * to be '*'. Otherwise for inline commands processInlineBuffer() is called. */ void processMultibulkBuffer(client *c) { char *newline = NULL; int ok; long long ll; int is_primary = c->read_flags & READ_FLAGS_PRIMARY; int auth_required = c->read_flags & READ_FLAGS_AUTH_REQUIRED; if (c->multibulklen == 0) { /* The client should have been reset */ serverAssertWithInfo(c, NULL, c->argc == 0); /* Multi bulk length cannot be read without a \r\n */ newline = strchr(c->querybuf + c->qb_pos, '\r'); if (newline == NULL) { if (sdslen(c->querybuf) - c->qb_pos > PROTO_INLINE_MAX_SIZE) { c->read_flags |= READ_FLAGS_ERROR_BIG_MULTIBULK; } return; } /* Buffer should also contain \n */ if (newline - (c->querybuf + c->qb_pos) > (ssize_t)(sdslen(c->querybuf) - c->qb_pos - 2)) return; /* We know for sure there is a whole line since newline != NULL, * so go ahead and find out the multi bulk length. */ serverAssertWithInfo(c, NULL, c->querybuf[c->qb_pos] == '*'); size_t multibulklen_slen = newline - (c->querybuf + 1 + c->qb_pos); ok = string2ll(c->querybuf + 1 + c->qb_pos, multibulklen_slen, &ll); if (!ok || ll > INT_MAX) { c->read_flags |= READ_FLAGS_ERROR_INVALID_MULTIBULK_LEN; return; } else if (ll > 10 && auth_required) { c->read_flags |= READ_FLAGS_ERROR_UNAUTHENTICATED_MULTIBULK_LEN; return; } c->qb_pos = (newline - c->querybuf) + 2; if (ll <= 0) { c->read_flags |= READ_FLAGS_PARSING_NEGATIVE_MBULK_LEN; return; } c->multibulklen = ll; /* Setup argv array on client structure */ if (c->argv) zfree(c->argv); c->argv_len = min(c->multibulklen, 1024); c->argv = zmalloc(sizeof(robj *) * c->argv_len); c->argv_len_sum = 0; /* Per-slot network bytes-in calculation. * * We calculate and store the current command's ingress bytes under * c->net_input_bytes_curr_cmd, for which its per-slot aggregation is deferred * until c->slot is parsed later within processCommand(). * * Calculation: For multi bulk buffer, we accumulate four factors, namely; * * 1) multibulklen_slen + 1 * Cumulative string length (and not the value of) of multibulklen, * including +1 from RESP first byte. * 2) bulklen_slen + c->argc * Cumulative string length (and not the value of) of bulklen, * including +1 from RESP first byte per argument count. * 3) c->argv_len_sum * Cumulative string length of all argument vectors. * 4) c->argc * 4 + 2 * Cumulative string length of all white-spaces, for which there exists a total of * 4 bytes per argument, plus 2 bytes from the leading '\r\n' from multibulklen. * * For example; * Command) SET key value * RESP) *3\r\n$3\r\nSET\r\n$3\r\nkey\r\n$5\r\nvalue\r\n * * 1) String length of "*3" is 2, obtained from (multibulklen_slen + 1). * 2) String length of "$3" "$3" "$5" is 6, obtained from (bulklen_slen + c->argc). * 3) String length of "SET" "key" "value" is 11, obtained from (c->argv_len_sum). * 4) String length of all white-spaces "\r\n" is 14, obtained from (c->argc * 4 + 2). * * The 1st component is calculated within the below line. * */ c->net_input_bytes_curr_cmd += (multibulklen_slen + 1); } serverAssertWithInfo(c, NULL, c->multibulklen > 0); while (c->multibulklen) { /* Read bulk length if unknown */ if (c->bulklen == -1) { newline = strchr(c->querybuf + c->qb_pos, '\r'); if (newline == NULL) { if (sdslen(c->querybuf) - c->qb_pos > PROTO_INLINE_MAX_SIZE) { c->read_flags |= READ_FLAGS_ERROR_BIG_BULK_COUNT; return; } break; } /* Buffer should also contain \n */ if (newline - (c->querybuf + c->qb_pos) > (ssize_t)(sdslen(c->querybuf) - c->qb_pos - 2)) break; if (c->querybuf[c->qb_pos] != '$') { c->read_flags |= READ_FLAGS_ERROR_MBULK_UNEXPECTED_CHARACTER; return; } size_t bulklen_slen = newline - (c->querybuf + c->qb_pos + 1); ok = string2ll(c->querybuf + c->qb_pos + 1, bulklen_slen, &ll); if (!ok || ll < 0 || (!(is_primary) && ll > server.proto_max_bulk_len)) { c->read_flags |= READ_FLAGS_ERROR_MBULK_INVALID_BULK_LEN; return; } else if (ll > 16384 && auth_required) { c->read_flags |= READ_FLAGS_ERROR_UNAUTHENTICATED_BULK_LEN; return; } c->qb_pos = newline - c->querybuf + 2; if (!(is_primary) && ll >= PROTO_MBULK_BIG_ARG) { /* When the client is not a primary client (because primary * client's querybuf can only be trimmed after data applied * and sent to replicas). * * If we are going to read a large object from network * try to make it likely that it will start at c->querybuf * boundary so that we can optimize object creation * avoiding a large copy of data. * * But only when the data we have not parsed is less than * or equal to ll+2. If the data length is greater than * ll+2, trimming querybuf is just a waste of time, because * at this time the querybuf contains not only our bulk. */ if (sdslen(c->querybuf) - c->qb_pos <= (size_t)ll + 2) { if (c->querybuf == thread_shared_qb) { /* Let the client take the ownership of the shared buffer. */ initSharedQueryBuf(); } sdsrange(c->querybuf, c->qb_pos, -1); c->qb_pos = 0; /* Hint the sds library about the amount of bytes this string is * going to contain. */ c->querybuf = sdsMakeRoomForNonGreedy(c->querybuf, ll + 2 - sdslen(c->querybuf)); /* We later set the peak to the used portion of the buffer, but here we over * allocated because we know what we need, make sure it'll not be shrunk before used. */ if (c->querybuf_peak < (size_t)ll + 2) c->querybuf_peak = ll + 2; } } c->bulklen = ll; /* Per-slot network bytes-in calculation, 2nd component. * c->argc portion is deferred, as it may not have been fully populated at this point. */ c->net_input_bytes_curr_cmd += bulklen_slen; } /* Read bulk argument */ if (sdslen(c->querybuf) - c->qb_pos < (size_t)(c->bulklen + 2)) { /* Not enough data (+2 == trailing \r\n) */ break; } else { /* Check if we have space in argv, grow if needed */ if (c->argc >= c->argv_len) { c->argv_len = min(c->argv_len < INT_MAX / 2 ? c->argv_len * 2 : INT_MAX, c->argc + c->multibulklen); c->argv = zrealloc(c->argv, sizeof(robj *) * c->argv_len); } /* Optimization: if a non-primary client's buffer contains JUST our bulk element * instead of creating a new object by *copying* the sds we * just use the current sds string. */ if (!is_primary && c->qb_pos == 0 && c->bulklen >= PROTO_MBULK_BIG_ARG && sdslen(c->querybuf) == (size_t)(c->bulklen + 2)) { c->argv[c->argc++] = createObject(OBJ_STRING, c->querybuf); c->argv_len_sum += c->bulklen; sdsIncrLen(c->querybuf, -2); /* remove CRLF */ /* Assume that if we saw a fat argument we'll see another one * likely... */ c->querybuf = sdsnewlen(SDS_NOINIT, c->bulklen + 2); sdsclear(c->querybuf); } else { c->argv[c->argc++] = createStringObject(c->querybuf + c->qb_pos, c->bulklen); c->argv_len_sum += c->bulklen; c->qb_pos += c->bulklen + 2; } c->bulklen = -1; c->multibulklen--; } } /* We're done when c->multibulk == 0 */ if (c->multibulklen == 0) { /* Per-slot network bytes-in calculation, 3rd and 4th components. * Here, the deferred c->argc from 2nd component is added, resulting in c->argc * 5 instead of * 4. */ c->net_input_bytes_curr_cmd += (c->argv_len_sum + (c->argc * 5 + 2)); c->read_flags |= READ_FLAGS_PARSING_COMPLETED; } } /* Perform necessary tasks after a command was executed: * * 1. The client is reset unless there are reasons to avoid doing it. * 2. In the case of primary clients, the replication offset is updated. * 3. Propagate commands we got from our primary to replicas down the line. */ void commandProcessed(client *c) { /* If client is blocked(including paused), just return avoid reset and replicate. * * 1. Don't reset the client structure for blocked clients, so that the reply * callback will still be able to access the client argv and argc fields. * The client will be reset in unblockClient(). * 2. Don't update replication offset or propagate commands to replicas, * since we have not applied the command. */ if (c->flag.blocked) return; reqresAppendResponse(c); clusterSlotStatsAddNetworkBytesInForUserClient(c); resetClient(c); long long prev_offset = c->reploff; if (c->flag.primary && !c->flag.multi) { /* Update the applied replication offset of our primary. */ c->reploff = c->read_reploff - sdslen(c->querybuf) + c->qb_pos; } /* If the client is a primary we need to compute the difference * between the applied offset before and after processing the buffer, * to understand how much of the replication stream was actually * applied to the primary state: this quantity, and its corresponding * part of the replication stream, will be propagated to the * sub-replicas and to the replication backlog. */ if (c->flag.primary) { long long applied = c->reploff - prev_offset; if (applied) { replicationFeedStreamFromPrimaryStream(c->querybuf + c->repl_applied, applied); c->repl_applied += applied; } } } /* This function calls processCommand(), but also performs a few sub tasks * for the client that are useful in that context: * * 1. It sets the current client to the client 'c'. * 2. calls commandProcessed() if the command was handled. * * The function returns C_ERR in case the client was freed as a side effect * of processing the command, otherwise C_OK is returned. */ int processCommandAndResetClient(client *c) { int deadclient = 0; client *old_client = server.current_client; server.current_client = c; if (processCommand(c) == C_OK) { commandProcessed(c); /* Update the client's memory to include output buffer growth following the * processed command. */ if (c->conn) updateClientMemUsageAndBucket(c); } if (server.current_client == NULL) deadclient = 1; /* * Restore the old client, this is needed because when a script * times out, we will get into this code from processEventsWhileBlocked. * Which will cause to set the server.current_client. If not restored * we will return 1 to our caller which will falsely indicate the client * is dead and will stop reading from its buffer. */ server.current_client = old_client; /* performEvictions may flush replica output buffers. This may * result in a replica, that may be the active client, to be * freed. */ return deadclient ? C_ERR : C_OK; } /* This function will execute any fully parsed commands pending on * the client. Returns C_ERR if the client is no longer valid after executing * the command, and C_OK for all other cases. */ int processPendingCommandAndInputBuffer(client *c) { /* Notice, this code is also called from 'processUnblockedClients'. * But in case of a module blocked client (see RM_Call 'K' flag) we do not reach this code path. * So whenever we change the code here we need to consider if we need this change on module * blocked client as well */ if (c->flag.pending_command) { c->flag.pending_command = 0; if (processCommandAndResetClient(c) == C_ERR) { return C_ERR; } } /* Now process client if it has more data in it's buffer. * * Note: when a primary client steps into this function, * it can always satisfy this condition, because its querybuf * contains data not applied. */ if (c->querybuf && sdslen(c->querybuf) > 0) { return processInputBuffer(c); } return C_OK; } /* Parse a single command from the query buf. * * This function may be called from the main thread or from the I/O thread. * * Sets the client's read_flags to indicate the parsing outcome */ void parseCommand(client *c) { /* Determine request type when unknown. */ if (!c->reqtype) { if (c->querybuf[c->qb_pos] == '*') { c->reqtype = PROTO_REQ_MULTIBULK; } else { c->reqtype = PROTO_REQ_INLINE; } } if (c->reqtype == PROTO_REQ_INLINE) { processInlineBuffer(c); } else if (c->reqtype == PROTO_REQ_MULTIBULK) { processMultibulkBuffer(c); } else { serverPanic("Unknown request type"); } } int canParseCommand(client *c) { if (c->cmd != NULL) return 0; /* Don't parse a command if the client is in the middle of something. */ if (c->flag.blocked || c->flag.unblocked) return 0; /* Don't process more buffers from clients that have already pending * commands to execute in c->argv. */ if (c->flag.pending_command) return 0; /* Don't process input from the primary while there is a busy script * condition on the replica. We want just to accumulate the replication * stream (instead of replying -BUSY like we do with other clients) and * later resume the processing. */ if (isInsideYieldingLongCommand() && c->flag.primary) return 0; /* CLIENT_CLOSE_AFTER_REPLY closes the connection once the reply is * written to the client. Make sure to not let the reply grow after * this flag has been set (i.e. don't process more commands). * * The same applies for clients we want to terminate ASAP. */ if (c->flag.close_after_reply || c->flag.close_asap) return 0; return 1; } int processInputBuffer(client *c) { /* Parse the query buffer. */ while (c->querybuf && c->qb_pos < sdslen(c->querybuf)) { if (!canParseCommand(c)) { break; } c->read_flags = c->flag.primary ? READ_FLAGS_PRIMARY : 0; c->read_flags |= authRequired(c) ? READ_FLAGS_AUTH_REQUIRED : 0; parseCommand(c); if (handleParseResults(c) != PARSE_OK) { break; } if (c->argc == 0) { /* No command to process - continue parsing the query buf. */ continue; } if (c->querybuf == thread_shared_qb) { /* Before processing the command, reset the shared query buffer to its default state. * This avoids unintentionally modifying the shared qb during processCommand as we may use * the shared qb for other clients during processEventsWhileBlocked */ resetSharedQueryBuf(c); } /* We are finally ready to execute the command. */ if (processCommandAndResetClient(c) == C_ERR) { /* If the client is no longer valid, we avoid exiting this * loop and trimming the client buffer later. So we return * ASAP in that case. */ return C_ERR; } } return C_OK; } /* This function can be called from the main-thread or from the IO-thread. * The function allocates query-buf for the client if required and reads to it from the network. * It will set c->nread to the bytes read from the network. */ void readToQueryBuf(client *c) { int big_arg = 0; size_t qblen, readlen; /* If the replica RDB client is marked as closed ASAP, do not try to read from it */ if (c->flag.close_asap) return; int is_primary = c->read_flags & READ_FLAGS_PRIMARY; readlen = PROTO_IOBUF_LEN; qblen = c->querybuf ? sdslen(c->querybuf) : 0; /* If this is a multi bulk request, and we are processing a bulk reply * that is large enough, try to maximize the probability that the query * buffer contains exactly the SDS string representing the object, even * at the risk of requiring more read(2) calls. This way the function * processMultiBulkBuffer() can avoid copying buffers to create the * robj representing the argument. */ if (c->reqtype == PROTO_REQ_MULTIBULK && c->multibulklen && c->bulklen != -1 && c->bulklen >= PROTO_MBULK_BIG_ARG) { ssize_t remaining = (size_t)(c->bulklen + 2) - (qblen - c->qb_pos); big_arg = 1; /* Note that the 'remaining' variable may be zero in some edge case, * for example once we resume a blocked client after CLIENT PAUSE. */ if (remaining > 0) readlen = remaining; /* Primary client needs expand the readlen when meet BIG_ARG(see #9100), * but doesn't need align to the next arg, we can read more data. */ if (c->flag.primary && readlen < PROTO_IOBUF_LEN) readlen = PROTO_IOBUF_LEN; } if (c->querybuf == NULL) { serverAssert(sdslen(thread_shared_qb) == 0); c->querybuf = big_arg ? sdsempty() : thread_shared_qb; qblen = sdslen(c->querybuf); } /* c->querybuf may be expanded. If so, the old thread_shared_qb will be released. * Although we have ensured that c->querybuf will not be expanded in the current * thread_shared_qb, we still add this check for code robustness. */ int use_thread_shared_qb = (c->querybuf == thread_shared_qb) ? 1 : 0; if (!is_primary && // primary client's querybuf can grow greedy. (big_arg || sdsalloc(c->querybuf) < PROTO_IOBUF_LEN)) { /* When reading a BIG_ARG we won't be reading more than that one arg * into the query buffer, so we don't need to pre-allocate more than we * need, so using the non-greedy growing. For an initial allocation of * the query buffer, we also don't wanna use the greedy growth, in order * to avoid collision with the RESIZE_THRESHOLD mechanism. */ c->querybuf = sdsMakeRoomForNonGreedy(c->querybuf, readlen); /* We later set the peak to the used portion of the buffer, but here we over * allocated because we know what we need, make sure it'll not be shrunk before used. */ if (c->querybuf_peak < qblen + readlen) c->querybuf_peak = qblen + readlen; } else { c->querybuf = sdsMakeRoomFor(c->querybuf, readlen); /* Read as much as possible from the socket to save read(2) system calls. */ readlen = sdsavail(c->querybuf); } if (use_thread_shared_qb) serverAssert(c->querybuf == thread_shared_qb); c->nread = connRead(c->conn, c->querybuf + qblen, readlen); if (c->nread <= 0) { return; } sdsIncrLen(c->querybuf, c->nread); qblen = sdslen(c->querybuf); if (c->querybuf_peak < qblen) c->querybuf_peak = qblen; if (!is_primary) { /* The commands cached in the MULTI/EXEC queue have not been executed yet, * so they are also considered a part of the query buffer in a broader sense. * * For unauthenticated clients, the query buffer cannot exceed 1MB at most. */ size_t qb_memory = sdslen(c->querybuf) + c->mstate.argv_len_sums; if (qb_memory > server.client_max_querybuf_len || (qb_memory > 1024 * 1024 && (c->read_flags & READ_FLAGS_AUTH_REQUIRED))) { c->read_flags |= READ_FLAGS_QB_LIMIT_REACHED; } } } void readQueryFromClient(connection *conn) { client *c = connGetPrivateData(conn); /* Check if we can send the client to be handled by the IO-thread */ if (postponeClientRead(c)) return; if (c->io_write_state != CLIENT_IDLE || c->io_read_state != CLIENT_IDLE) return; readToQueryBuf(c); if (handleReadResult(c) == C_OK) { if (processInputBuffer(c) == C_ERR) return; } beforeNextClient(c); } /* An "Address String" is a colon separated ip:port pair. * For IPv4 it's in the form x.y.z.k:port, example: "127.0.0.1:1234". * For IPv6 addresses we use [] around the IP part, like in "[::1]:1234". * For Unix sockets we use path:0, like in "/tmp/redis:0". * * An Address String always fits inside a buffer of NET_ADDR_STR_LEN bytes, * including the null term. * * On failure the function still populates 'addr' with the "?:0" string in case * you want to relax error checking or need to display something anyway (see * anetFdToString implementation for more info). */ void genClientAddrString(client *client, char *addr, size_t addr_len, int remote) { if (client->flag.unix_socket) { /* Unix socket client. */ snprintf(addr, addr_len, "%s:0", server.unixsocket); } else { /* TCP client. */ connFormatAddr(client->conn, addr, addr_len, remote); } } /* This function returns the client peer id, by creating and caching it * if client->peerid is NULL, otherwise returning the cached value. * The Peer ID never changes during the life of the client, however it * is expensive to compute. */ char *getClientPeerId(client *c) { char peerid[NET_ADDR_STR_LEN] = {0}; if (c->peerid == NULL) { genClientAddrString(c, peerid, sizeof(peerid), 1); c->peerid = sdsnew(peerid); } return c->peerid; } /* This function returns the client bound socket name, by creating and caching * it if client->sockname is NULL, otherwise returning the cached value. * The Socket Name never changes during the life of the client, however it * is expensive to compute. */ char *getClientSockname(client *c) { char sockname[NET_ADDR_STR_LEN] = {0}; if (c->sockname == NULL) { genClientAddrString(c, sockname, sizeof(sockname), 0); c->sockname = sdsnew(sockname); } return c->sockname; } int isClientConnIpV6(client *c) { /* The cached client peer id is on the form "[IPv6]:port" for IPv6 * addresses, so we just check for '[' here. */ if (c->flag.fake && server.current_client) { /* Fake client? Use current client instead. * Noted that in here we are assuming server.current_client is set * and real (aof has already violated this in loadSingleAppendOnlyFil). */ c = server.current_client; } return getClientPeerId(c)[0] == '['; } /* Concatenate a string representing the state of a client in a human * readable format, into the sds string 's'. */ sds catClientInfoString(sds s, client *client, int hide_user_data) { if (!server.crashed) waitForClientIO(client); char flags[17], events[3], conninfo[CONN_INFO_LEN], *p; p = flags; if (client->flag.replica) { if (client->flag.monitor) *p++ = 'O'; else *p++ = 'S'; } if (client->flag.primary) *p++ = 'M'; if (client->flag.pubsub) *p++ = 'P'; if (client->flag.multi) *p++ = 'x'; if (client->flag.blocked) *p++ = 'b'; if (client->flag.tracking) *p++ = 't'; if (client->flag.tracking_broken_redir) *p++ = 'R'; if (client->flag.tracking_bcast) *p++ = 'B'; if (client->flag.dirty_cas) *p++ = 'd'; if (client->flag.close_after_reply) *p++ = 'c'; if (client->flag.unblocked) *p++ = 'u'; if (client->flag.close_asap) *p++ = 'A'; if (client->flag.unix_socket) *p++ = 'U'; if (client->flag.readonly) *p++ = 'r'; if (client->flag.no_evict) *p++ = 'e'; if (client->flag.no_touch) *p++ = 'T'; if (p == flags) *p++ = 'N'; *p++ = '\0'; p = events; if (client->conn) { if (connHasReadHandler(client->conn)) *p++ = 'r'; if (connHasWriteHandler(client->conn)) *p++ = 'w'; } *p = '\0'; /* Compute the total memory consumed by this client. */ size_t obufmem, total_mem = getClientMemoryUsage(client, &obufmem); size_t used_blocks_of_repl_buf = 0; if (client->ref_repl_buf_node) { replBufBlock *last = listNodeValue(listLast(server.repl_buffer_blocks)); replBufBlock *cur = listNodeValue(client->ref_repl_buf_node); used_blocks_of_repl_buf = last->id - cur->id + 1; } sds ret = sdscatfmt( s, FMTARGS( "id=%U", (unsigned long long)client->id, " addr=%s", getClientPeerId(client), " laddr=%s", getClientSockname(client), " %s", connGetInfo(client->conn, conninfo, sizeof(conninfo)), " name=%s", hide_user_data ? "*redacted*" : (client->name ? (char *)client->name->ptr : ""), " age=%I", (long long)(commandTimeSnapshot() / 1000 - client->ctime), " idle=%I", (long long)(server.unixtime - client->last_interaction), " flags=%s", flags, " db=%i", client->db->id, " sub=%i", (int)dictSize(client->pubsub_channels), " psub=%i", (int)dictSize(client->pubsub_patterns), " ssub=%i", (int)dictSize(client->pubsubshard_channels), " multi=%i", (client->flag.multi) ? client->mstate.count : -1, " watch=%i", (int)listLength(client->watched_keys), " qbuf=%U", client->querybuf ? (unsigned long long)sdslen(client->querybuf) : 0, " qbuf-free=%U", client->querybuf ? (unsigned long long)sdsavail(client->querybuf) : 0, " argv-mem=%U", (unsigned long long)client->argv_len_sum, " multi-mem=%U", (unsigned long long)client->mstate.argv_len_sums, " rbs=%U", (unsigned long long)client->buf_usable_size, " rbp=%U", (unsigned long long)client->buf_peak, " obl=%U", (unsigned long long)client->bufpos, " oll=%U", (unsigned long long)listLength(client->reply) + used_blocks_of_repl_buf, " omem=%U", (unsigned long long)obufmem, /* should not include client->buf since we want to see 0 for static clients. */ " tot-mem=%U", (unsigned long long)total_mem, " events=%s", events, " cmd=%s", client->lastcmd ? client->lastcmd->fullname : "NULL", " user=%s", hide_user_data ? "*redacted*" : (client->user ? client->user->name : "(superuser)"), " redir=%I", (client->flag.tracking) ? (long long)client->client_tracking_redirection : -1, " resp=%i", client->resp, " lib-name=%s", client->lib_name ? (char *)client->lib_name->ptr : "", " lib-ver=%s", client->lib_ver ? (char *)client->lib_ver->ptr : "", " tot-net-in=%U", client->net_input_bytes, " tot-net-out=%U", client->net_output_bytes, " tot-cmds=%U", client->commands_processed)); return ret; } sds getAllClientsInfoString(int type, int hide_user_data) { listNode *ln; listIter li; client *client; sds o = sdsnewlen(SDS_NOINIT, 200 * listLength(server.clients)); sdsclear(o); listRewind(server.clients, &li); while ((ln = listNext(&li)) != NULL) { client = listNodeValue(ln); if (type != -1 && getClientType(client) != type) continue; o = catClientInfoString(o, client, hide_user_data); o = sdscatlen(o, "\n", 1); } return o; } /* Check validity of an attribute that's gonna be shown in CLIENT LIST. */ int validateClientAttr(const char *val) { /* Check if the charset is ok. We need to do this otherwise * CLIENT LIST format will break. You should always be able to * split by space to get the different fields. */ while (*val) { if (*val < '!' || *val > '~') { /* ASCII is assumed. */ return C_ERR; } val++; } return C_OK; } /* Returns C_OK if the name is valid. Returns C_ERR & sets `err` (when provided) otherwise. */ int validateClientName(robj *name, const char **err) { const char *err_msg = "Client names cannot contain spaces, newlines or special characters."; int len = (name != NULL) ? sdslen(name->ptr) : 0; /* We allow setting the client name to an empty string. */ if (len == 0) return C_OK; if (validateClientAttr(name->ptr) == C_ERR) { if (err) *err = err_msg; return C_ERR; } return C_OK; } /* Returns C_OK if the name has been set or C_ERR if the name is invalid. */ int clientSetName(client *c, robj *name, const char **err) { if (validateClientName(name, err) == C_ERR) { return C_ERR; } int len = (name != NULL) ? sdslen(name->ptr) : 0; /* Setting the client name to an empty string actually removes * the current name. */ if (len == 0) { if (c->name) decrRefCount(c->name); c->name = NULL; return C_OK; } if (c->name) decrRefCount(c->name); c->name = name; incrRefCount(name); return C_OK; } /* This function implements CLIENT SETNAME, including replying to the * user with an error if the charset is wrong (in that case C_ERR is * returned). If the function succeeded C_OK is returned, and it's up * to the caller to send a reply if needed. * * Setting an empty string as name has the effect of unsetting the * currently set name: the client will remain unnamed. * * This function is also used to implement the HELLO SETNAME option. */ int clientSetNameOrReply(client *c, robj *name) { const char *err = NULL; int result = clientSetName(c, name, &err); if (result == C_ERR) { addReplyError(c, err); } return result; } /* Set client or connection related info */ void clientSetinfoCommand(client *c) { sds attr = c->argv[2]->ptr; robj *valob = c->argv[3]; sds val = valob->ptr; robj **destvar = NULL; if (!strcasecmp(attr, "lib-name")) { destvar = &c->lib_name; } else if (!strcasecmp(attr, "lib-ver")) { destvar = &c->lib_ver; } else { addReplyErrorFormat(c, "Unrecognized option '%s'", attr); return; } if (validateClientAttr(val) == C_ERR) { addReplyErrorFormat(c, "%s cannot contain spaces, newlines or special characters.", attr); return; } if (*destvar) decrRefCount(*destvar); if (sdslen(val)) { *destvar = valob; incrRefCount(valob); } else *destvar = NULL; addReply(c, shared.ok); } /* Reset the client state to resemble a newly connected client. */ void resetCommand(client *c) { /* MONITOR clients are also marked with CLIENT_REPLICA, we need to * distinguish between the two. */ struct ClientFlags flags = c->flag; if (flags.monitor) { flags.monitor = 0; flags.replica = 0; } if (flags.replica || flags.primary || flags.module) { addReplyError(c, "can only reset normal client connections"); return; } clearClientConnectionState(c); addReplyStatus(c, "RESET"); } /* Disconnect the current client */ void quitCommand(client *c) { addReply(c, shared.ok); c->flag.close_after_reply = 1; } void clientCommand(client *c) { listNode *ln; listIter li; if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr, "help")) { const char *help[] = { "CACHING (YES|NO)", " Enable/disable tracking of the keys for next command in OPTIN/OPTOUT modes.", "CAPA