/*
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Copyright (c) 2010-2018 Roger Light <roger@atchoo.org>
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All rights reserved. This program and the accompanying materials
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are made available under the terms of the Eclipse Public License v1.0
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and Eclipse Distribution License v1.0 which accompany this distribution.
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The Eclipse Public License is available at
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http://www.eclipse.org/legal/epl-v10.html
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and the Eclipse Distribution License is available at
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http://www.eclipse.org/org/documents/edl-v10.php.
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Contributors:
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Roger Light - initial implementation and documentation.
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*/
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#include "config.h"
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#ifdef WITH_PERSISTENCE
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#ifndef WIN32
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#include <arpa/inet.h>
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#endif
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#include <assert.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include <string.h>
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#include <sys/stat.h>
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#include <time.h>
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#include "mosquitto_broker_internal.h"
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#include "memory_mosq.h"
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#include "persist.h"
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#include "time_mosq.h"
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#include "util_mosq.h"
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static int persist__client_messages_save(struct mosquitto_db *db, FILE *db_fptr, struct mosquitto *context, struct mosquitto_client_msg *queue)
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{
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struct P_client_msg chunk;
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struct mosquitto_client_msg *cmsg;
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int rc;
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assert(db);
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assert(db_fptr);
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assert(context);
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memset(&chunk, 0, sizeof(struct P_client_msg));
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cmsg = queue;
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while(cmsg){
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if(!strncmp(cmsg->store->topic, "$SYS", 4)
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&& cmsg->store->ref_count <= 1
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&& cmsg->store->dest_id_count == 0){
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/* This $SYS message won't have been persisted, so we can't persist
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* this client message. */
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cmsg = cmsg->next;
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continue;
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}
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chunk.F.store_id = cmsg->store->db_id;
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chunk.F.mid = cmsg->mid;
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chunk.F.id_len = strlen(context->id);
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chunk.F.qos = cmsg->qos;
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chunk.F.retain_dup = (cmsg->retain&0x0F)<<4 | (cmsg->dup&0x0F);
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chunk.F.direction = cmsg->direction;
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chunk.F.state = cmsg->state;
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chunk.client_id = context->id;
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chunk.properties = cmsg->properties;
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rc = persist__chunk_client_msg_write_v5(db_fptr, &chunk);
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if(rc){
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return rc;
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}
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cmsg = cmsg->next;
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}
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return MOSQ_ERR_SUCCESS;
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}
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static int persist__message_store_save(struct mosquitto_db *db, FILE *db_fptr)
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{
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struct P_msg_store chunk;
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struct mosquitto_msg_store *stored;
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int rc;
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assert(db);
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assert(db_fptr);
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memset(&chunk, 0, sizeof(struct P_msg_store));
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stored = db->msg_store;
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while(stored){
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if(stored->ref_count < 1 || stored->topic == NULL){
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stored = stored->next;
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continue;
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}
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if(!strncmp(stored->topic, "$SYS", 4)){
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if(stored->ref_count <= 1 && stored->dest_id_count == 0){
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/* $SYS messages that are only retained shouldn't be persisted. */
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stored = stored->next;
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continue;
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}
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/* Don't save $SYS messages as retained otherwise they can give
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* misleading information when reloaded. They should still be saved
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* because a disconnected durable client may have them in their
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* queue. */
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chunk.F.retain = 0;
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}else{
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chunk.F.retain = (uint8_t)stored->retain;
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}
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chunk.F.store_id = stored->db_id;
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chunk.F.expiry_time = stored->message_expiry_time;
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chunk.F.payloadlen = stored->payloadlen;
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chunk.F.source_mid = stored->source_mid;
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if(stored->source_id){
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chunk.F.source_id_len = strlen(stored->source_id);
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chunk.source.id = stored->source_id;
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}else{
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chunk.F.source_id_len = 0;
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chunk.source.id = NULL;
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}
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if(stored->source_username){
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chunk.F.source_username_len = strlen(stored->source_username);
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chunk.source.username = stored->source_username;
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}else{
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chunk.F.source_username_len = 0;
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chunk.source.username = NULL;
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}
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chunk.F.topic_len = strlen(stored->topic);
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chunk.topic = stored->topic;
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if(stored->source_listener){
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chunk.F.source_port = stored->source_listener->port;
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}else{
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chunk.F.source_port = 0;
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}
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chunk.F.qos = stored->qos;
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chunk.payload = stored->payload;
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chunk.properties = stored->properties;
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rc = persist__chunk_message_store_write_v5(db_fptr, &chunk);
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if(rc){
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return rc;
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}
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stored = stored->next;
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}
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return MOSQ_ERR_SUCCESS;
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}
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static int persist__client_save(struct mosquitto_db *db, FILE *db_fptr)
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{
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struct mosquitto *context, *ctxt_tmp;
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struct P_client chunk;
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int rc;
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assert(db);
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assert(db_fptr);
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memset(&chunk, 0, sizeof(struct P_client));
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HASH_ITER(hh_id, db->contexts_by_id, context, ctxt_tmp){
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if(context && context->clean_start == false){
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chunk.F.session_expiry_time = context->session_expiry_time;
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chunk.F.session_expiry_interval = context->session_expiry_interval;
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chunk.F.last_mid = context->last_mid;
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chunk.F.id_len = strlen(context->id);
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chunk.client_id = context->id;
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rc = persist__chunk_client_write_v5(db_fptr, &chunk);
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if(rc){
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return rc;
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}
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if(persist__client_messages_save(db, db_fptr, context, context->msgs_in.inflight)) return 1;
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if(persist__client_messages_save(db, db_fptr, context, context->msgs_in.queued)) return 1;
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if(persist__client_messages_save(db, db_fptr, context, context->msgs_out.inflight)) return 1;
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if(persist__client_messages_save(db, db_fptr, context, context->msgs_out.queued)) return 1;
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}
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}
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return MOSQ_ERR_SUCCESS;
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}
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static int persist__subs_retain_save(struct mosquitto_db *db, FILE *db_fptr, struct mosquitto__subhier *node, const char *topic, int level)
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{
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struct mosquitto__subhier *subhier, *subhier_tmp;
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struct mosquitto__subleaf *sub;
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struct P_retain retain_chunk;
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struct P_sub sub_chunk;
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char *thistopic;
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size_t slen;
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int rc;
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memset(&retain_chunk, 0, sizeof(struct P_retain));
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memset(&sub_chunk, 0, sizeof(struct P_sub));
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slen = strlen(topic) + node->topic_len + 2;
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thistopic = mosquitto__malloc(sizeof(char)*slen);
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if(!thistopic) return MOSQ_ERR_NOMEM;
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if(level > 1 || strlen(topic)){
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snprintf(thistopic, slen, "%s/%s", topic, node->topic);
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}else{
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snprintf(thistopic, slen, "%s", node->topic);
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}
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sub = node->subs;
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while(sub){
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if(sub->context->clean_start == false && sub->context->id){
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sub_chunk.F.identifier = sub->identifier;
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sub_chunk.F.id_len = strlen(sub->context->id);
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sub_chunk.F.topic_len = strlen(thistopic);
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sub_chunk.F.qos = (uint8_t)sub->qos;
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sub_chunk.F.options = sub->no_local<<2 | sub->retain_as_published<<3;
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sub_chunk.client_id = sub->context->id;
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sub_chunk.topic = thistopic;
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rc = persist__chunk_sub_write_v5(db_fptr, &sub_chunk);
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if(rc){
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mosquitto__free(thistopic);
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return rc;
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}
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}
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sub = sub->next;
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}
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if(node->retained){
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if(strncmp(node->retained->topic, "$SYS", 4)){
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/* Don't save $SYS messages. */
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retain_chunk.F.store_id = node->retained->db_id;
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rc = persist__chunk_retain_write_v5(db_fptr, &retain_chunk);
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if(rc){
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mosquitto__free(thistopic);
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return rc;
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}
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}
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}
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HASH_ITER(hh, node->children, subhier, subhier_tmp){
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persist__subs_retain_save(db, db_fptr, subhier, thistopic, level+1);
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}
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mosquitto__free(thistopic);
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return MOSQ_ERR_SUCCESS;
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}
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static int persist__subs_retain_save_all(struct mosquitto_db *db, FILE *db_fptr)
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{
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struct mosquitto__subhier *subhier, *subhier_tmp;
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HASH_ITER(hh, db->subs, subhier, subhier_tmp){
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if(subhier->children){
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persist__subs_retain_save(db, db_fptr, subhier->children, "", 0);
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}
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}
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return MOSQ_ERR_SUCCESS;
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}
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int persist__backup(struct mosquitto_db *db, bool shutdown)
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{
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int rc = 0;
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FILE *db_fptr = NULL;
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uint32_t db_version_w = htonl(MOSQ_DB_VERSION);
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uint32_t crc = 0;
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char *err;
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char *outfile = NULL;
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int len;
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struct PF_cfg cfg_chunk;
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if(!db || !db->config || !db->config->persistence_filepath) return MOSQ_ERR_INVAL;
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if(db->config->persistence == false) return MOSQ_ERR_SUCCESS;
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log__printf(NULL, MOSQ_LOG_INFO, "Saving in-memory database to %s.", db->config->persistence_filepath);
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len = strlen(db->config->persistence_filepath)+5;
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outfile = mosquitto__malloc(len+1);
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if(!outfile){
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log__printf(NULL, MOSQ_LOG_INFO, "Error saving in-memory database, out of memory.");
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return MOSQ_ERR_NOMEM;
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}
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snprintf(outfile, len, "%s.new", db->config->persistence_filepath);
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outfile[len] = '\0';
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#ifndef WIN32
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/**
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*
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* If a system lost power during the rename operation at the
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* end of this file the filesystem could potentially be left
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* with a directory that looks like this after powerup:
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*
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* 24094 -rw-r--r-- 2 root root 4099 May 30 16:27 mosquitto.db
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* 24094 -rw-r--r-- 2 root root 4099 May 30 16:27 mosquitto.db.new
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*
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* The 24094 shows that mosquitto.db.new is hard-linked to the
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* same file as mosquitto.db. If fopen(outfile, "wb") is naively
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* called then mosquitto.db will be truncated and the database
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* potentially corrupted.
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*
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* Any existing mosquitto.db.new file must be removed prior to
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* opening to guarantee that it is not hard-linked to
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* mosquitto.db.
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*
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*/
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rc = unlink(outfile);
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if (rc != 0) {
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rc = 0;
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if (errno != ENOENT) {
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log__printf(NULL, MOSQ_LOG_INFO, "Error saving in-memory database, unable to remove %s.", outfile);
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goto error;
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}
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}
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#endif
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db_fptr = mosquitto__fopen(outfile, "wb", true);
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if(db_fptr == NULL){
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log__printf(NULL, MOSQ_LOG_INFO, "Error saving in-memory database, unable to open %s for writing.", outfile);
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goto error;
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}
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/* Header */
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write_e(db_fptr, magic, 15);
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write_e(db_fptr, &crc, sizeof(uint32_t));
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write_e(db_fptr, &db_version_w, sizeof(uint32_t));
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memset(&cfg_chunk, 0, sizeof(struct PF_cfg));
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cfg_chunk.last_db_id = db->last_db_id;
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cfg_chunk.shutdown = shutdown;
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cfg_chunk.dbid_size = sizeof(dbid_t);
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if(persist__chunk_cfg_write_v5(db_fptr, &cfg_chunk)){
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goto error;
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}
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if(persist__message_store_save(db, db_fptr)){
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goto error;
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}
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persist__client_save(db, db_fptr);
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persist__subs_retain_save_all(db, db_fptr);
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#ifndef WIN32
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/**
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*
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* Closing a file does not guarantee that the contents are
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* written to disk. Need to flush to send data from app to OS
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* buffers, then fsync to deliver data from OS buffers to disk
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* (as well as disk hardware permits).
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*
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* man close (http://linux.die.net/man/2/close, 2016-06-20):
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*
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* "successful close does not guarantee that the data has
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* been successfully saved to disk, as the kernel defers
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* writes. It is not common for a filesystem to flush
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* the buffers when the stream is closed. If you need
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* to be sure that the data is physically stored, use
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* fsync(2). (It will depend on the disk hardware at this
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* point."
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*
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* This guarantees that the new state file will not overwrite
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* the old state file before its contents are valid.
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*
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*/
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fflush(db_fptr);
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fsync(fileno(db_fptr));
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#endif
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fclose(db_fptr);
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#ifdef WIN32
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if(remove(db->config->persistence_filepath) != 0){
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if(errno != ENOENT){
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goto error;
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}
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}
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#endif
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if(rename(outfile, db->config->persistence_filepath) != 0){
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goto error;
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}
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mosquitto__free(outfile);
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outfile = NULL;
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return rc;
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error:
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mosquitto__free(outfile);
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err = strerror(errno);
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log__printf(NULL, MOSQ_LOG_ERR, "Error: %s.", err);
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if(db_fptr) fclose(db_fptr);
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return 1;
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}
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#endif
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