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test
aws-iot/src/aws_iot_mqtt_client_unsubscribe.cpp
- Committer:
- peyo
- Date:
- 2017-04-12
- Revision:
- 0:cd5404401c2f
File content as of revision 0:cd5404401c2f:
/* * Copyright 2015-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved. * * Licensed under the Apache License, Version 2.0 (the "License"). * You may not use this file except in compliance with the License. * A copy of the License is located at * * http://aws.amazon.com/apache2.0 * * or in the "license" file accompanying this file. This file is distributed * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either * express or implied. See the License for the specific language governing * permissions and limitations under the License. */ // Based on Eclipse Paho. /******************************************************************************* * Copyright (c) 2014 IBM Corp. * * 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: * Ian Craggs - initial API and implementation and/or initial documentation *******************************************************************************/ /** * @file aws_iot_mqtt_client_unsubscribe.c * @brief MQTT client unsubscribe API definitions */ #ifdef __cplusplus extern "C" { #endif #include "aws_iot_mqtt_client_common_internal.h" /** * Serializes the supplied unsubscribe data into the supplied buffer, ready for sending * @param pTxBuf the raw buffer data, of the correct length determined by the remaining length field * @param txBufLen the length in bytes of the data in the supplied buffer * @param dup integer - the MQTT dup flag * @param packetId integer - the MQTT packet identifier * @param count - number of members in the topicFilters array * @param pTopicNameList - array of topic filter names * @param pTopicNameLenList - array of length of topic filter names in pTopicNameList * @param pSerializedLen - the length of the serialized data * @return IoT_Error_t indicating function execution status */ static IoT_Error_t _aws_iot_mqtt_serialize_unsubscribe(unsigned char *pTxBuf, size_t txBufLen, uint8_t dup, uint16_t packetId, uint32_t count, const char **pTopicNameList, uint16_t *pTopicNameLenList, uint32_t *pSerializedLen) { unsigned char *ptr = pTxBuf; uint32_t i = 0; uint32_t rem_len = 2; /* packetId */ IoT_Error_t rc; MQTTHeader header = {0}; FUNC_ENTRY; for(i = 0; i < count; ++i) { rem_len += (uint32_t) (pTopicNameLenList[i] + 2); /* topic + length */ } if(aws_iot_mqtt_internal_get_final_packet_length_from_remaining_length(rem_len) > txBufLen) { FUNC_EXIT_RC(MQTT_TX_BUFFER_TOO_SHORT_ERROR); } rc = aws_iot_mqtt_internal_init_header(&header, UNSUBSCRIBE, QOS1, dup, 0); if(SUCCESS != rc) { FUNC_EXIT_RC(rc); } aws_iot_mqtt_internal_write_char(&ptr, header.byte); /* write header */ ptr += aws_iot_mqtt_internal_write_len_to_buffer(ptr, rem_len); /* write remaining length */ aws_iot_mqtt_internal_write_uint_16(&ptr, packetId); for(i = 0; i < count; ++i) { aws_iot_mqtt_internal_write_utf8_string(&ptr, pTopicNameList[i], pTopicNameLenList[i]); } *pSerializedLen = (uint32_t) (ptr - pTxBuf); FUNC_EXIT_RC(SUCCESS); } /** * Deserializes the supplied (wire) buffer into unsuback data * @param pPacketId returned integer - the MQTT packet identifier * @param pRxBuf the raw buffer data, of the correct length determined by the remaining length field * @param rxBufLen the length in bytes of the data in the supplied buffer * @return IoT_Error_t indicating function execution status */ static IoT_Error_t _aws_iot_mqtt_deserialize_unsuback(uint16_t *pPacketId, unsigned char *pRxBuf, size_t rxBufLen) { unsigned char type = 0; unsigned char dup = 0; IoT_Error_t rc; FUNC_ENTRY; rc = aws_iot_mqtt_internal_deserialize_ack(&type, &dup, pPacketId, pRxBuf, rxBufLen); if(SUCCESS == rc && UNSUBACK != type) { rc = FAILURE; } FUNC_EXIT_RC(rc); } /** * @brief Unsubscribe to an MQTT topic. * * Called to send an unsubscribe message to the broker requesting removal of a subscription * to an MQTT topic. * @note Call is blocking. The call returns after the receipt of the UNSUBACK control packet. * This is the internal function which is called by the unsubscribe API to perform the operation. * Not meant to be called directly as it doesn't do validations or client state changes * * @param pClient Reference to the IoT Client * @param pTopicName Topic Name to publish to * @param topicNameLen Length of the topic name * * @return An IoT Error Type defining successful/failed unsubscribe call */ static IoT_Error_t _aws_iot_mqtt_internal_unsubscribe(AWS_IoT_Client *pClient, const char *pTopicFilter, uint16_t topicFilterLen) { /* No NULL checks because this is a static internal function */ TimerAWS timer; uint16_t packet_id; uint32_t serializedLen = 0; uint32_t i = 0; IoT_Error_t rc; bool subscriptionExists = false; FUNC_ENTRY; /* Remove from message handler array */ for(i = 0; i < AWS_IOT_MQTT_NUM_SUBSCRIBE_HANDLERS; ++i) { if(pClient->clientData.messageHandlers[i].topicName != NULL && (strcmp(pClient->clientData.messageHandlers[i].topicName, pTopicFilter) == 0)) { subscriptionExists = true; } } if(false == subscriptionExists) { FUNC_EXIT_RC(FAILURE); } init_timer(&timer); countdown_ms(&timer, pClient->clientData.commandTimeoutMs); rc = _aws_iot_mqtt_serialize_unsubscribe(pClient->clientData.writeBuf, pClient->clientData.writeBufSize, 0, aws_iot_mqtt_get_next_packet_id(pClient), 1, &pTopicFilter, &topicFilterLen, &serializedLen); if(SUCCESS != rc) { FUNC_EXIT_RC(rc); } /* send the unsubscribe packet */ rc = aws_iot_mqtt_internal_send_packet(pClient, serializedLen, &timer); if(SUCCESS != rc) { FUNC_EXIT_RC(rc); } rc = aws_iot_mqtt_internal_wait_for_read(pClient, UNSUBACK, &timer); if(SUCCESS != rc) { FUNC_EXIT_RC(rc); } rc = _aws_iot_mqtt_deserialize_unsuback(&packet_id, pClient->clientData.readBuf, pClient->clientData.readBufSize); if(SUCCESS != rc) { FUNC_EXIT_RC(rc); } /* Remove from message handler array */ for(i = 0; i < AWS_IOT_MQTT_NUM_SUBSCRIBE_HANDLERS; ++i) { if(pClient->clientData.messageHandlers[i].topicName != NULL && (strcmp(pClient->clientData.messageHandlers[i].topicName, pTopicFilter) == 0)) { pClient->clientData.messageHandlers[i].topicName = NULL; /* We don't want to break here, in case the same topic is registered * with 2 callbacks. Unlikely scenario */ } } FUNC_EXIT_RC(SUCCESS); } /** * @brief Unsubscribe to an MQTT topic. * * Called to send an unsubscribe message to the broker requesting removal of a subscription * to an MQTT topic. * @note Call is blocking. The call returns after the receipt of the UNSUBACK control packet. * This is the outer function which does the validations and calls the internal unsubscribe above * to perform the actual operation. It is also responsible for client state changes * * @param pClient Reference to the IoT Client * @param pTopicName Topic Name to publish to * @param topicNameLen Length of the topic name * * @return An IoT Error Type defining successful/failed unsubscribe call */ IoT_Error_t aws_iot_mqtt_unsubscribe(AWS_IoT_Client *pClient, const char *pTopicFilter, uint16_t topicFilterLen) { IoT_Error_t rc, unsubRc; ClientState clientState; if(NULL == pClient || NULL == pTopicFilter) { return NULL_VALUE_ERROR; } if(!aws_iot_mqtt_is_client_connected(pClient)) { return NETWORK_DISCONNECTED_ERROR; } clientState = aws_iot_mqtt_get_client_state(pClient); if(CLIENT_STATE_CONNECTED_IDLE != clientState && CLIENT_STATE_CONNECTED_WAIT_FOR_CB_RETURN != clientState) { return MQTT_CLIENT_NOT_IDLE_ERROR; } rc = aws_iot_mqtt_set_client_state(pClient, clientState, CLIENT_STATE_CONNECTED_UNSUBSCRIBE_IN_PROGRESS); if(SUCCESS != rc) { rc = aws_iot_mqtt_set_client_state(pClient, CLIENT_STATE_CONNECTED_UNSUBSCRIBE_IN_PROGRESS, clientState); return rc; } unsubRc = _aws_iot_mqtt_internal_unsubscribe(pClient, pTopicFilter, topicFilterLen); rc = aws_iot_mqtt_set_client_state(pClient, CLIENT_STATE_CONNECTED_UNSUBSCRIBE_IN_PROGRESS, clientState); if(SUCCESS == unsubRc && SUCCESS != rc) { unsubRc = rc; } return unsubRc; } #ifdef __cplusplus } #endif