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core_mqtt.c
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core_mqtt.c
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/*
* coreMQTT v2.1.0
* Copyright (C) 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* SPDX-License-Identifier: MIT
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
/**
* @file core_mqtt.c
* @brief Implements the user-facing functions in core_mqtt.h.
*/
#include <string.h>
#include <assert.h>
#include "core_mqtt.h"
#include "core_mqtt_state.h"
/* Include config defaults header to get default values of configs. */
#include "core_mqtt_config_defaults.h"
#ifndef MQTT_PRE_SEND_HOOK
/**
* @brief Hook called before a 'send' operation is executed.
*/
#define MQTT_PRE_SEND_HOOK( pContext )
#endif /* !MQTT_PRE_SEND_HOOK */
#ifndef MQTT_POST_SEND_HOOK
/**
* @brief Hook called after the 'send' operation is complete.
*/
#define MQTT_POST_SEND_HOOK( pContext )
#endif /* !MQTT_POST_SEND_HOOK */
#ifndef MQTT_PRE_STATE_UPDATE_HOOK
/**
* @brief Hook called just before an update to the MQTT state is made.
*/
#define MQTT_PRE_STATE_UPDATE_HOOK( pContext )
#endif /* !MQTT_PRE_STATE_UPDATE_HOOK */
#ifndef MQTT_POST_STATE_UPDATE_HOOK
/**
* @brief Hook called just after an update to the MQTT state has
* been made.
*/
#define MQTT_POST_STATE_UPDATE_HOOK( pContext )
#endif /* !MQTT_POST_STATE_UPDATE_HOOK */
/**
* @brief Bytes required to encode any string length in an MQTT packet header.
* Length is always encoded in two bytes according to the MQTT specification.
*/
#define CORE_MQTT_SERIALIZED_LENGTH_FIELD_BYTES ( 2U )
/**
* @brief Number of vectors required to encode one topic filter in a subscribe
* request. Three vectors are required as there are three fields in the
* subscribe request namely:
* 1. Topic filter length; 2. Topic filter; and 3. QoS in this order.
*/
#define CORE_MQTT_SUBSCRIBE_PER_TOPIC_VECTOR_LENGTH ( 3U )
/**
* @brief Number of vectors required to encode one topic filter in an
* unsubscribe request. Two vectors are required as there are two fields in the
* unsubscribe request namely:
* 1. Topic filter length; and 2. Topic filter in this order.
*/
#define CORE_MQTT_UNSUBSCRIBE_PER_TOPIC_VECTOR_LENGTH ( 2U )
/*-----------------------------------------------------------*/
/**
* @brief Sends provided buffer to network using transport send.
*
* @brief param[in] pContext Initialized MQTT context.
* @brief param[in] pBufferToSend Buffer to be sent to network.
* @brief param[in] bytesToSend Number of bytes to be sent.
*
* @note This operation may call the transport send function
* repeatedly to send bytes over the network until either:
* 1. The requested number of bytes @a bytesToSend have been sent.
* OR
* 2. MQTT_SEND_TIMEOUT_MS milliseconds have gone by since entering this
* function.
* OR
* 3. There is an error in sending data over the network.
*
* @return Total number of bytes sent, or negative value on network error.
*/
static int32_t sendBuffer( MQTTContext_t * pContext,
const uint8_t * pBufferToSend,
size_t bytesToSend );
/**
* @brief Sends MQTT connect without copying the users data into any buffer.
*
* @brief param[in] pContext Initialized MQTT context.
* @brief param[in] pConnectInfo MQTT CONNECT packet information.
* @brief param[in] pWillInfo Last Will and Testament. Pass NULL if Last Will and
* Testament is not used.
* @brief param[in] remainingLength the length of the connect packet.
*
* @note This operation may call the transport send function
* repeatedly to send bytes over the network until either:
* 1. The requested number of bytes @a remainingLength have been sent.
* OR
* 2. MQTT_SEND_TIMEOUT_MS milliseconds have gone by since entering this
* function.
* OR
* 3. There is an error in sending data over the network.
*
* @return #MQTTSendFailed or #MQTTSuccess.
*/
static MQTTStatus_t sendConnectWithoutCopy( MQTTContext_t * pContext,
const MQTTConnectInfo_t * pConnectInfo,
const MQTTPublishInfo_t * pWillInfo,
size_t remainingLength );
/**
* @brief Sends the vector array passed through the parameters over the network.
*
* @note The preference is given to 'writev' function if it is present in the
* transport interface. Otherwise, a send call is made repeatedly to achieve the
* result.
*
* @param[in] pContext Initialized MQTT context.
* @param[in] pIoVec The vector array to be sent.
* @param[in] ioVecCount The number of elements in the array.
*
* @note This operation may call the transport send or writev functions
* repeatedly to send bytes over the network until either:
* 1. The requested number of bytes have been sent.
* OR
* 2. MQTT_SEND_TIMEOUT_MS milliseconds have gone by since entering this
* function.
* OR
* 3. There is an error in sending data over the network.
*
* @return The total number of bytes sent or the error code as received from the
* transport interface.
*/
static int32_t sendMessageVector( MQTTContext_t * pContext,
TransportOutVector_t * pIoVec,
size_t ioVecCount );
/**
* @brief Add a string and its length after serializing it in a manner outlined by
* the MQTT specification.
*
* @param[in] serializedLength Array of two bytes to which the vector will point.
* The array must remain in scope until the message has been sent.
* @param[in] string The string to be serialized.
* @param[in] length The length of the string to be serialized.
* @param[in] iterator The iterator pointing to the first element in the
* transport interface IO array.
* @param[out] updatedLength This parameter will be added to with the number of
* bytes added to the vector.
*
* @return The number of vectors added.
*/
static size_t addEncodedStringToVector( uint8_t serializedLength[ CORE_MQTT_SERIALIZED_LENGTH_FIELD_BYTES ],
const char * const string,
uint16_t length,
TransportOutVector_t * iterator,
size_t * updatedLength );
/**
* @brief Send MQTT SUBSCRIBE message without copying the user data into a buffer and
* directly sending it.
*
* @param[in] pContext Initialized MQTT context.
* @param[in] pSubscriptionList List of MQTT subscription info.
* @param[in] subscriptionCount The count of elements in the list.
* @param[in] packetId The packet ID of the subscribe packet
* @param[in] remainingLength The remaining length of the subscribe packet.
*
* @return #MQTTSuccess or #MQTTSendFailed.
*/
static MQTTStatus_t sendSubscribeWithoutCopy( MQTTContext_t * pContext,
const MQTTSubscribeInfo_t * pSubscriptionList,
size_t subscriptionCount,
uint16_t packetId,
size_t remainingLength );
/**
* @brief Send MQTT UNSUBSCRIBE message without copying the user data into a buffer and
* directly sending it.
*
* @param[in] pContext Initialized MQTT context.
* @param[in] pSubscriptionList MQTT subscription info.
* @param[in] subscriptionCount The count of elements in the list.
* @param[in] packetId The packet ID of the unsubscribe packet.
* @param[in] remainingLength The remaining length of the unsubscribe packet.
*
* @return #MQTTSuccess or #MQTTSendFailed.
*/
static MQTTStatus_t sendUnsubscribeWithoutCopy( MQTTContext_t * pContext,
const MQTTSubscribeInfo_t * pSubscriptionList,
size_t subscriptionCount,
uint16_t packetId,
size_t remainingLength );
/**
* @brief Calculate the interval between two millisecond timestamps, including
* when the later value has overflowed.
*
* @note In C, the operands are promoted to signed integers in subtraction.
* Using this function avoids the need to cast the result of subtractions back
* to uint32_t.
*
* @param[in] later The later time stamp, in milliseconds.
* @param[in] start The earlier time stamp, in milliseconds.
*
* @return later - start.
*/
static uint32_t calculateElapsedTime( uint32_t later,
uint32_t start );
/**
* @brief Convert a byte indicating a publish ack type to an #MQTTPubAckType_t.
*
* @param[in] packetType First byte of fixed header.
*
* @return Type of ack.
*/
static MQTTPubAckType_t getAckFromPacketType( uint8_t packetType );
/**
* @brief Receive bytes into the network buffer.
*
* @param[in] pContext Initialized MQTT Context.
* @param[in] bytesToRecv Number of bytes to receive.
*
* @note This operation calls the transport receive function
* repeatedly to read bytes from the network until either:
* 1. The requested number of bytes @a bytesToRecv are read.
* OR
* 2. No data is received from the network for MQTT_RECV_POLLING_TIMEOUT_MS duration.
*
* OR
* 3. There is an error in reading from the network.
*
*
* @return Number of bytes received, or negative number on network error.
*/
static int32_t recvExact( const MQTTContext_t * pContext,
size_t bytesToRecv );
/**
* @brief Discard a packet from the transport interface.
*
* @param[in] pContext MQTT Connection context.
* @param[in] remainingLength Remaining length of the packet to dump.
* @param[in] timeoutMs Time remaining to discard the packet.
*
* @return #MQTTRecvFailed or #MQTTNoDataAvailable.
*/
static MQTTStatus_t discardPacket( const MQTTContext_t * pContext,
size_t remainingLength,
uint32_t timeoutMs );
/**
* @brief Discard a packet from the MQTT buffer and the transport interface.
*
* @param[in] pContext MQTT Connection context.
* @param[in] pPacketInfo Information struct of the packet to be discarded.
*
* @return #MQTTRecvFailed or #MQTTNoDataAvailable.
*/
static MQTTStatus_t discardStoredPacket( MQTTContext_t * pContext,
const MQTTPacketInfo_t * pPacketInfo );
/**
* @brief Receive a packet from the transport interface.
*
* @param[in] pContext MQTT Connection context.
* @param[in] incomingPacket packet struct with remaining length.
* @param[in] remainingTimeMs Time remaining to receive the packet.
*
* @return #MQTTSuccess or #MQTTRecvFailed.
*/
static MQTTStatus_t receivePacket( const MQTTContext_t * pContext,
MQTTPacketInfo_t incomingPacket,
uint32_t remainingTimeMs );
/**
* @brief Get the correct ack type to send.
*
* @param[in] state Current state of publish.
*
* @return Packet Type byte of PUBACK, PUBREC, PUBREL, or PUBCOMP if one of
* those should be sent, else 0.
*/
static uint8_t getAckTypeToSend( MQTTPublishState_t state );
/**
* @brief Send acks for received QoS 1/2 publishes.
*
* @param[in] pContext MQTT Connection context.
* @param[in] packetId packet ID of original PUBLISH.
* @param[in] publishState Current publish state in record.
*
* @return #MQTTSuccess, #MQTTIllegalState or #MQTTSendFailed.
*/
static MQTTStatus_t sendPublishAcks( MQTTContext_t * pContext,
uint16_t packetId,
MQTTPublishState_t publishState );
/**
* @brief Send a keep alive PINGREQ if the keep alive interval has elapsed.
*
* @param[in] pContext Initialized MQTT Context.
*
* @return #MQTTKeepAliveTimeout if a PINGRESP is not received in time,
* #MQTTSendFailed if the PINGREQ cannot be sent, or #MQTTSuccess.
*/
static MQTTStatus_t handleKeepAlive( MQTTContext_t * pContext );
/**
* @brief Handle received MQTT PUBLISH packet.
*
* @param[in] pContext MQTT Connection context.
* @param[in] pIncomingPacket Incoming packet.
*
* @return MQTTSuccess, MQTTIllegalState or deserialization error.
*/
static MQTTStatus_t handleIncomingPublish( MQTTContext_t * pContext,
MQTTPacketInfo_t * pIncomingPacket );
/**
* @brief Handle received MQTT publish acks.
*
* @param[in] pContext MQTT Connection context.
* @param[in] pIncomingPacket Incoming packet.
*
* @return MQTTSuccess, MQTTIllegalState, or deserialization error.
*/
static MQTTStatus_t handlePublishAcks( MQTTContext_t * pContext,
MQTTPacketInfo_t * pIncomingPacket );
/**
* @brief Handle received MQTT ack.
*
* @param[in] pContext MQTT Connection context.
* @param[in] pIncomingPacket Incoming packet.
* @param[in] manageKeepAlive Flag indicating if PINGRESPs should not be given
* to the application
*
* @return MQTTSuccess, MQTTIllegalState, or deserialization error.
*/
static MQTTStatus_t handleIncomingAck( MQTTContext_t * pContext,
MQTTPacketInfo_t * pIncomingPacket,
bool manageKeepAlive );
/**
* @brief Run a single iteration of the receive loop.
*
* @param[in] pContext MQTT Connection context.
* @param[in] manageKeepAlive Flag indicating if keep alive should be handled.
*
* @return #MQTTRecvFailed if a network error occurs during reception;
* #MQTTSendFailed if a network error occurs while sending an ACK or PINGREQ;
* #MQTTBadResponse if an invalid packet is received;
* #MQTTKeepAliveTimeout if the server has not sent a PINGRESP before
* #MQTT_PINGRESP_TIMEOUT_MS milliseconds;
* #MQTTIllegalState if an incoming QoS 1/2 publish or ack causes an
* invalid transition for the internal state machine;
* #MQTTSuccess on success.
*/
static MQTTStatus_t receiveSingleIteration( MQTTContext_t * pContext,
bool manageKeepAlive );
/**
* @brief Validates parameters of #MQTT_Subscribe or #MQTT_Unsubscribe.
*
* @param[in] pContext Initialized MQTT context.
* @param[in] pSubscriptionList List of MQTT subscription info.
* @param[in] subscriptionCount The number of elements in pSubscriptionList.
* @param[in] packetId Packet identifier.
*
* @return #MQTTBadParameter if invalid parameters are passed;
* #MQTTSuccess otherwise.
*/
static MQTTStatus_t validateSubscribeUnsubscribeParams( const MQTTContext_t * pContext,
const MQTTSubscribeInfo_t * pSubscriptionList,
size_t subscriptionCount,
uint16_t packetId );
/**
* @brief Receives a CONNACK MQTT packet.
*
* @param[in] pContext Initialized MQTT context.
* @param[in] timeoutMs Timeout for waiting for CONNACK packet.
* @param[in] cleanSession Clean session flag set by application.
* @param[out] pIncomingPacket List of MQTT subscription info.
* @param[out] pSessionPresent Whether a previous session was present.
* Only relevant if not establishing a clean session.
*
* @return #MQTTBadResponse if a bad response is received;
* #MQTTNoDataAvailable if no data available for transport recv;
* ##MQTTRecvFailed if transport recv failed;
* #MQTTSuccess otherwise.
*/
static MQTTStatus_t receiveConnack( const MQTTContext_t * pContext,
uint32_t timeoutMs,
bool cleanSession,
MQTTPacketInfo_t * pIncomingPacket,
bool * pSessionPresent );
/**
* @brief Resends pending acks for a re-established MQTT session, or
* clears existing state records for a clean session.
*
* @param[in] pContext Initialized MQTT context.
* @param[in] sessionPresent Session present flag received from the MQTT broker.
*
* @return #MQTTSendFailed if transport send during resend failed;
* #MQTTSuccess otherwise.
*/
static MQTTStatus_t handleSessionResumption( MQTTContext_t * pContext,
bool sessionPresent );
/**
* @brief Send the publish packet without copying the topic string and payload in
* the buffer.
*
* @brief param[in] pContext Initialized MQTT context.
* @brief param[in] pPublishInfo MQTT PUBLISH packet parameters.
* @brief param[in] pMqttHeader the serialized MQTT header with the header byte;
* the encoded length of the packet; and the encoded length of the topic string.
* @brief param[in] headerSize Size of the serialized PUBLISH header.
* @brief param[in] packetId Packet Id of the publish packet.
*
* @return #MQTTSendFailed if transport send during resend failed;
* #MQTTSuccess otherwise.
*/
static MQTTStatus_t sendPublishWithoutCopy( MQTTContext_t * pContext,
const MQTTPublishInfo_t * pPublishInfo,
const uint8_t * pMqttHeader,
size_t headerSize,
uint16_t packetId );
/**
* @brief Function to validate #MQTT_Publish parameters.
*
* @brief param[in] pContext Initialized MQTT context.
* @brief param[in] pPublishInfo MQTT PUBLISH packet parameters.
* @brief param[in] packetId Packet Id for the MQTT PUBLISH packet.
*
* @return #MQTTBadParameter if invalid parameters are passed;
* #MQTTSuccess otherwise.
*/
static MQTTStatus_t validatePublishParams( const MQTTContext_t * pContext,
const MQTTPublishInfo_t * pPublishInfo,
uint16_t packetId );
/**
* @brief Performs matching for special cases when a topic filter ends
* with a wildcard character.
*
* When the topic name has been consumed but there are remaining characters to
* to match in topic filter, this function handles the following 2 cases:
* - When the topic filter ends with "/+" or "/#" characters, but the topic
* name only ends with '/'.
* - When the topic filter ends with "/#" characters, but the topic name
* ends at the parent level.
*
* @note This function ASSUMES that the topic name been consumed in linear
* matching with the topic filer, but the topic filter has remaining characters
* to be matched.
*
* @param[in] pTopicFilter The topic filter containing the wildcard.
* @param[in] topicFilterLength Length of the topic filter being examined.
* @param[in] filterIndex Index of the topic filter being examined.
*
* @return Returns whether the topic filter and the topic name match.
*/
static bool matchEndWildcardsSpecialCases( const char * pTopicFilter,
uint16_t topicFilterLength,
uint16_t filterIndex );
/**
* @brief Attempt to match topic name with a topic filter starting with a wildcard.
*
* If the topic filter starts with a '+' (single-level) wildcard, the function
* advances the @a pNameIndex by a level in the topic name.
* If the topic filter starts with a '#' (multi-level) wildcard, the function
* concludes that both the topic name and topic filter match.
*
* @param[in] pTopicName The topic name to match.
* @param[in] topicNameLength Length of the topic name.
* @param[in] pTopicFilter The topic filter to match.
* @param[in] topicFilterLength Length of the topic filter.
* @param[in,out] pNameIndex Current index in the topic name being examined. It is
* advanced by one level for `+` wildcards.
* @param[in, out] pFilterIndex Current index in the topic filter being examined.
* It is advanced to position of '/' level separator for '+' wildcard.
* @param[out] pMatch Whether the topic filter and topic name match.
*
* @return `true` if the caller of this function should exit; `false` if the
* caller should continue parsing the topics.
*/
static bool matchWildcards( const char * pTopicName,
uint16_t topicNameLength,
const char * pTopicFilter,
uint16_t topicFilterLength,
uint16_t * pNameIndex,
uint16_t * pFilterIndex,
bool * pMatch );
/**
* @brief Match a topic name and topic filter allowing the use of wildcards.
*
* @param[in] pTopicName The topic name to check.
* @param[in] topicNameLength Length of the topic name.
* @param[in] pTopicFilter The topic filter to check.
* @param[in] topicFilterLength Length of topic filter.
*
* @return `true` if the topic name and topic filter match; `false` otherwise.
*/
static bool matchTopicFilter( const char * pTopicName,
uint16_t topicNameLength,
const char * pTopicFilter,
uint16_t topicFilterLength );
/*-----------------------------------------------------------*/
static bool matchEndWildcardsSpecialCases( const char * pTopicFilter,
uint16_t topicFilterLength,
uint16_t filterIndex )
{
bool matchFound = false;
assert( pTopicFilter != NULL );
assert( topicFilterLength != 0U );
/* Check if the topic filter has 2 remaining characters and it ends in
* "/#". This check handles the case to match filter "sport/#" with topic
* "sport". The reason is that the '#' wildcard represents the parent and
* any number of child levels in the topic name.*/
if( ( topicFilterLength >= 3U ) &&
( filterIndex == ( topicFilterLength - 3U ) ) &&
( pTopicFilter[ filterIndex + 1U ] == '/' ) &&
( pTopicFilter[ filterIndex + 2U ] == '#' ) )
{
matchFound = true;
}
/* Check if the next character is "#" or "+" and the topic filter ends in
* "/#" or "/+". This check handles the cases to match:
*
* - Topic filter "sport/+" with topic "sport/".
* - Topic filter "sport/#" with topic "sport/".
*/
if( ( filterIndex == ( topicFilterLength - 2U ) ) &&
( pTopicFilter[ filterIndex ] == '/' ) )
{
/* Check that the last character is a wildcard. */
matchFound = ( pTopicFilter[ filterIndex + 1U ] == '+' ) ||
( pTopicFilter[ filterIndex + 1U ] == '#' );
}
return matchFound;
}
/*-----------------------------------------------------------*/
static bool matchWildcards( const char * pTopicName,
uint16_t topicNameLength,
const char * pTopicFilter,
uint16_t topicFilterLength,
uint16_t * pNameIndex,
uint16_t * pFilterIndex,
bool * pMatch )
{
bool shouldStopMatching = false;
bool locationIsValidForWildcard;
assert( pTopicName != NULL );
assert( topicNameLength != 0U );
assert( pTopicFilter != NULL );
assert( topicFilterLength != 0U );
assert( pNameIndex != NULL );
assert( pFilterIndex != NULL );
assert( pMatch != NULL );
/* Wild card in a topic filter is only valid either at the starting position
* or when it is preceded by a '/'.*/
locationIsValidForWildcard = ( *pFilterIndex == 0u ) ||
( pTopicFilter[ *pFilterIndex - 1U ] == '/' );
if( ( pTopicFilter[ *pFilterIndex ] == '+' ) && ( locationIsValidForWildcard == true ) )
{
bool nextLevelExistsInTopicName = false;
bool nextLevelExistsinTopicFilter = false;
/* Move topic name index to the end of the current level. The end of the
* current level is identified by the last character before the next level
* separator '/'. */
while( *pNameIndex < topicNameLength )
{
/* Exit the loop if we hit the level separator. */
if( pTopicName[ *pNameIndex ] == '/' )
{
nextLevelExistsInTopicName = true;
break;
}
( *pNameIndex )++;
}
/* Determine if the topic filter contains a child level after the current level
* represented by the '+' wildcard. */
if( ( *pFilterIndex < ( topicFilterLength - 1U ) ) &&
( pTopicFilter[ *pFilterIndex + 1U ] == '/' ) )
{
nextLevelExistsinTopicFilter = true;
}
/* If the topic name contains a child level but the topic filter ends at
* the current level, then there does not exist a match. */
if( ( nextLevelExistsInTopicName == true ) &&
( nextLevelExistsinTopicFilter == false ) )
{
*pMatch = false;
shouldStopMatching = true;
}
/* If the topic name and topic filter have child levels, then advance the
* filter index to the level separator in the topic filter, so that match
* can be performed in the next level.
* Note: The name index already points to the level separator in the topic
* name. */
else if( nextLevelExistsInTopicName == true )
{
( *pFilterIndex )++;
}
else
{
/* If we have reached here, the the loop terminated on the
* ( *pNameIndex < topicNameLength) condition, which means that have
* reached past the end of the topic name, and thus, we decrement the
* index to the last character in the topic name.*/
( *pNameIndex )--;
}
}
/* '#' matches everything remaining in the topic name. It must be the
* last character in a topic filter. */
else if( ( pTopicFilter[ *pFilterIndex ] == '#' ) &&
( *pFilterIndex == ( topicFilterLength - 1U ) ) &&
( locationIsValidForWildcard == true ) )
{
/* Subsequent characters don't need to be checked for the
* multi-level wildcard. */
*pMatch = true;
shouldStopMatching = true;
}
else
{
/* Any character mismatch other than '+' or '#' means the topic
* name does not match the topic filter. */
*pMatch = false;
shouldStopMatching = true;
}
return shouldStopMatching;
}
/*-----------------------------------------------------------*/
static bool matchTopicFilter( const char * pTopicName,
uint16_t topicNameLength,
const char * pTopicFilter,
uint16_t topicFilterLength )
{
bool matchFound = false, shouldStopMatching = false;
uint16_t nameIndex = 0, filterIndex = 0;
assert( pTopicName != NULL );
assert( topicNameLength != 0 );
assert( pTopicFilter != NULL );
assert( topicFilterLength != 0 );
while( ( nameIndex < topicNameLength ) && ( filterIndex < topicFilterLength ) )
{
/* Check if the character in the topic name matches the corresponding
* character in the topic filter string. */
if( pTopicName[ nameIndex ] == pTopicFilter[ filterIndex ] )
{
/* If the topic name has been consumed but the topic filter has not
* been consumed, match for special cases when the topic filter ends
* with wildcard character. */
if( nameIndex == ( topicNameLength - 1U ) )
{
matchFound = matchEndWildcardsSpecialCases( pTopicFilter,
topicFilterLength,
filterIndex );
}
}
else
{
/* Check for matching wildcards. */
shouldStopMatching = matchWildcards( pTopicName,
topicNameLength,
pTopicFilter,
topicFilterLength,
&nameIndex,
&filterIndex,
&matchFound );
}
if( ( matchFound == true ) || ( shouldStopMatching == true ) )
{
break;
}
/* Increment indexes. */
nameIndex++;
filterIndex++;
}
if( matchFound == false )
{
/* If the end of both strings has been reached, they match. This represents the
* case when the topic filter contains the '+' wildcard at a non-starting position.
* For example, when matching either of "sport/+/player" OR "sport/hockey/+" topic
* filters with "sport/hockey/player" topic name. */
matchFound = ( nameIndex == topicNameLength ) &&
( filterIndex == topicFilterLength );
}
return matchFound;
}
/*-----------------------------------------------------------*/
static int32_t sendMessageVector( MQTTContext_t * pContext,
TransportOutVector_t * pIoVec,
size_t ioVecCount )
{
int32_t sendResult;
uint32_t startTime;
TransportOutVector_t * pIoVectIterator;
size_t vectorsToBeSent = ioVecCount;
size_t bytesToSend = 0U;
int32_t bytesSentOrError = 0;
assert( pContext != NULL );
assert( pIoVec != NULL );
assert( pContext->getTime != NULL );
/* Send must always be defined */
assert( pContext->transportInterface.send != NULL );
/* Count the total number of bytes to be sent as outlined in the vector. */
for( pIoVectIterator = pIoVec; pIoVectIterator <= &( pIoVec[ ioVecCount - 1U ] ); pIoVectIterator++ )
{
bytesToSend += pIoVectIterator->iov_len;
}
/* Reset the iterator to point to the first entry in the array. */
pIoVectIterator = pIoVec;
/* Note the start time. */
startTime = pContext->getTime();
while( ( bytesSentOrError < ( int32_t ) bytesToSend ) && ( bytesSentOrError >= 0 ) )
{
if( pContext->transportInterface.writev != NULL )
{
sendResult = pContext->transportInterface.writev( pContext->transportInterface.pNetworkContext,
pIoVectIterator,
vectorsToBeSent );
}
else
{
sendResult = pContext->transportInterface.send( pContext->transportInterface.pNetworkContext,
pIoVectIterator->iov_base,
pIoVectIterator->iov_len );
}
if( sendResult > 0 )
{
/* It is a bug in the application's transport send implementation if
* more bytes than expected are sent. */
assert( sendResult <= ( ( int32_t ) bytesToSend - bytesSentOrError ) );
bytesSentOrError += sendResult;
/* Set last transmission time. */
pContext->lastPacketTxTime = pContext->getTime();
LogDebug( ( "sendMessageVector: Bytes Sent=%ld, Bytes Remaining=%lu",
( long int ) sendResult,
( unsigned long ) ( bytesToSend - ( size_t ) bytesSentOrError ) ) );
}
else if( sendResult < 0 )
{
bytesSentOrError = sendResult;
LogError( ( "sendMessageVector: Unable to send packet: Network Error." ) );
}
else
{
/* MISRA Empty body */
}
/* Check for timeout. */
if( calculateElapsedTime( pContext->getTime(), startTime ) > MQTT_SEND_TIMEOUT_MS )
{
LogError( ( "sendMessageVector: Unable to send packet: Timed out." ) );
break;
}
/* Update the send pointer to the correct vector and offset. */
while( ( pIoVectIterator <= &( pIoVec[ ioVecCount - 1U ] ) ) &&
( sendResult >= ( int32_t ) pIoVectIterator->iov_len ) )
{
sendResult -= ( int32_t ) pIoVectIterator->iov_len;
pIoVectIterator++;
/* Update the number of vector which are yet to be sent. */
vectorsToBeSent--;
}
/* Some of the bytes from this vector were sent as well, update the length
* and the pointer to data in this vector. */
if( ( sendResult > 0 ) &&
( pIoVectIterator <= &( pIoVec[ ioVecCount - 1U ] ) ) )
{
pIoVectIterator->iov_base = ( const void * ) &( ( ( const uint8_t * ) pIoVectIterator->iov_base )[ sendResult ] );
pIoVectIterator->iov_len -= ( size_t ) sendResult;
}
}
return bytesSentOrError;
}
static int32_t sendBuffer( MQTTContext_t * pContext,
const uint8_t * pBufferToSend,
size_t bytesToSend )
{
int32_t sendResult;
uint32_t timeoutMs;
int32_t bytesSentOrError = 0;
const uint8_t * pIndex = pBufferToSend;
assert( pContext != NULL );
assert( pContext->getTime != NULL );
assert( pContext->transportInterface.send != NULL );
assert( pIndex != NULL );
/* Set the timeout. */
timeoutMs = pContext->getTime() + MQTT_SEND_TIMEOUT_MS;
while( ( bytesSentOrError < ( int32_t ) bytesToSend ) && ( bytesSentOrError >= 0 ) )
{
sendResult = pContext->transportInterface.send( pContext->transportInterface.pNetworkContext,
pIndex,
bytesToSend - ( size_t ) bytesSentOrError );
if( sendResult > 0 )
{
/* It is a bug in the application's transport send implementation if
* more bytes than expected are sent. */
assert( sendResult <= ( ( int32_t ) bytesToSend - bytesSentOrError ) );
bytesSentOrError += sendResult;
pIndex = &pIndex[ sendResult ];
/* Set last transmission time. */
pContext->lastPacketTxTime = pContext->getTime();
LogDebug( ( "sendBuffer: Bytes Sent=%ld, Bytes Remaining=%lu",
( long int ) sendResult,
( unsigned long ) ( bytesToSend - ( size_t ) bytesSentOrError ) ) );
}
else if( sendResult < 0 )
{
bytesSentOrError = sendResult;
LogError( ( "sendBuffer: Unable to send packet: Network Error." ) );
}
else
{
/* MISRA Empty body */
}
/* Check for timeout. */
if( pContext->getTime() >= timeoutMs )
{
LogError( ( "sendBuffer: Unable to send packet: Timed out." ) );
break;
}
}
return bytesSentOrError;
}
/*-----------------------------------------------------------*/
static uint32_t calculateElapsedTime( uint32_t later,
uint32_t start )
{
return later - start;
}
/*-----------------------------------------------------------*/
static MQTTPubAckType_t getAckFromPacketType( uint8_t packetType )
{
MQTTPubAckType_t ackType = MQTTPuback;
switch( packetType )
{
case MQTT_PACKET_TYPE_PUBACK:
ackType = MQTTPuback;
break;
case MQTT_PACKET_TYPE_PUBREC:
ackType = MQTTPubrec;
break;
case MQTT_PACKET_TYPE_PUBREL:
ackType = MQTTPubrel;
break;
case MQTT_PACKET_TYPE_PUBCOMP:
default:
/* This function is only called after checking the type is one of
* the above four values, so packet type must be PUBCOMP here. */
assert( packetType == MQTT_PACKET_TYPE_PUBCOMP );
ackType = MQTTPubcomp;
break;
}
return ackType;
}
/*-----------------------------------------------------------*/
static int32_t recvExact( const MQTTContext_t * pContext,
size_t bytesToRecv )
{
uint8_t * pIndex = NULL;
size_t bytesRemaining = bytesToRecv;
int32_t totalBytesRecvd = 0, bytesRecvd;
uint32_t lastDataRecvTimeMs = 0U, timeSinceLastRecvMs = 0U;
TransportRecv_t recvFunc = NULL;
MQTTGetCurrentTimeFunc_t getTimeStampMs = NULL;
bool receiveError = false;
assert( pContext != NULL );
assert( bytesToRecv <= pContext->networkBuffer.size );
assert( pContext->getTime != NULL );
assert( pContext->transportInterface.recv != NULL );
assert( pContext->networkBuffer.pBuffer != NULL );
pIndex = pContext->networkBuffer.pBuffer;
recvFunc = pContext->transportInterface.recv;
getTimeStampMs = pContext->getTime;
/* Part of the MQTT packet has been read before calling this function. */
lastDataRecvTimeMs = getTimeStampMs();
while( ( bytesRemaining > 0U ) && ( receiveError == false ) )
{
bytesRecvd = recvFunc( pContext->transportInterface.pNetworkContext,
pIndex,
bytesRemaining );
if( bytesRecvd < 0 )
{
LogError( ( "Network error while receiving packet: ReturnCode=%ld.",
( long int ) bytesRecvd ) );
totalBytesRecvd = bytesRecvd;
receiveError = true;