mosquitto/lib/handle_pubrel.c

/*
Copyright (c) 2009-2018 Roger Light <roger@atchoo.org>

All rights reserved. This program and the accompanying materials
are made available under the terms of the Eclipse Public License v1.0
and Eclipse Distribution License v1.0 which accompany this distribution.

The Eclipse Public License is available at
   http://www.eclipse.org/legal/epl-v10.html
and the Eclipse Distribution License is available at
  http://www.eclipse.org/org/documents/edl-v10.php.

Contributors:
   Roger Light - initial implementation and documentation.
*/

#include "config.h"

#include <assert.h>
#include <stdio.h>
#include <string.h>

#ifdef WITH_BROKER
#  include "mosquitto_broker_internal.h"
#endif

#include "mosquitto.h"
#include "logging_mosq.h"
#include "memory_mosq.h"
#include "messages_mosq.h"
#include "mqtt_protocol.h"
#include "net_mosq.h"
#include "packet_mosq.h"
#include "read_handle.h"
#include "send_mosq.h"
#include "util_mosq.h"


int handle__pubrel(struct mosquitto_db *db, struct mosquitto *mosq)
{
	uint16_t mid;
#ifndef WITH_BROKER
	struct mosquitto_message_all *message = NULL;
#endif
	int rc;

	assert(mosq);
	if(mosq->protocol == mosq_p_mqtt311){
		if((mosq->in_packet.command&0x0F) != 0x02){
			return MOSQ_ERR_PROTOCOL;
		}
	}
	rc = packet__read_uint16(&mosq->in_packet, &mid);
	if(rc) return rc;
#ifdef WITH_BROKER
	log__printf(NULL, MOSQ_LOG_DEBUG, "Received PUBREL from %s (Mid: %d)", mosq->id, mid);

	if(db__message_release(db, mosq, mid, mosq_md_in)){
		/* Message not found. Still send a PUBCOMP anyway because this could be
		 * due to a repeated PUBREL after a client has reconnected. */
		log__printf(mosq, MOSQ_LOG_WARNING, "Warning: Received PUBREL from %s for an unknown packet identifier %d.", mosq->id, mid);
	}
#else
	log__printf(mosq, MOSQ_LOG_DEBUG, "Client %s received PUBREL (Mid: %d)", mosq->id, mid);

	if(!message__remove(mosq, mid, mosq_md_in, &message)){
		/* Only pass the message on if we have removed it from the queue - this
		 * prevents multiple callbacks for the same message. */
		pthread_mutex_lock(&mosq->callback_mutex);
		if(mosq->on_message){
			mosq->in_callback = true;
			mosq->on_message(mosq, mosq->userdata, &message->msg);
			mosq->in_callback = false;
		}
		pthread_mutex_unlock(&mosq->callback_mutex);
		message__cleanup(&message);
	}
#endif
	rc = send__pubcomp(mosq, mid);
	if(rc) return rc;

	return MOSQ_ERR_SUCCESS;
}