MQTTStatus_t MQTT_DeserializeAck()

in source/core_mqtt_serializer.c [2278:2351]
59 lines of code
17 McCabe index (conditional complexity)

MQTTStatus_t MQTT_DeserializeAck( const MQTTPacketInfo_t * pIncomingPacket,
                                  uint16_t * pPacketId,
                                  bool * pSessionPresent )
{
    MQTTStatus_t status = MQTTSuccess;

    if( pIncomingPacket == NULL )
    {
        LogError( ( "pIncomingPacket cannot be NULL." ) );
        status = MQTTBadParameter;
    }

    /* Pointer for packet identifier cannot be NULL for packets other than
     * CONNACK and PINGRESP. */
    else if( ( pPacketId == NULL ) &&
             ( ( pIncomingPacket->type != MQTT_PACKET_TYPE_CONNACK ) &&
               ( pIncomingPacket->type != MQTT_PACKET_TYPE_PINGRESP ) ) )
    {
        LogError( ( "pPacketId cannot be NULL for packet type %02x.",
                    ( unsigned int ) pIncomingPacket->type ) );
        status = MQTTBadParameter;
    }
    /* Pointer for session present cannot be NULL for CONNACK. */
    else if( ( pSessionPresent == NULL ) &&
             ( pIncomingPacket->type == MQTT_PACKET_TYPE_CONNACK ) )
    {
        LogError( ( "pSessionPresent cannot be NULL for CONNACK packet." ) );
        status = MQTTBadParameter;
    }

    /* Pointer for remaining data cannot be NULL for packets other
     * than PINGRESP. */
    else if( ( pIncomingPacket->pRemainingData == NULL ) &&
             ( pIncomingPacket->type != MQTT_PACKET_TYPE_PINGRESP ) )
    {
        LogError( ( "Remaining data of incoming packet is NULL." ) );
        status = MQTTBadParameter;
    }
    else
    {
        /* Make sure response packet is a valid ack. */
        switch( pIncomingPacket->type )
        {
            case MQTT_PACKET_TYPE_CONNACK:
                status = deserializeConnack( pIncomingPacket, pSessionPresent );
                break;

            case MQTT_PACKET_TYPE_SUBACK:
                status = deserializeSuback( pIncomingPacket, pPacketId );
                break;

            case MQTT_PACKET_TYPE_PINGRESP:
                status = deserializePingresp( pIncomingPacket );
                break;

            case MQTT_PACKET_TYPE_UNSUBACK:
            case MQTT_PACKET_TYPE_PUBACK:
            case MQTT_PACKET_TYPE_PUBREC:
            case MQTT_PACKET_TYPE_PUBREL:
            case MQTT_PACKET_TYPE_PUBCOMP:
                status = deserializeSimpleAck( pIncomingPacket, pPacketId );
                break;

            /* Any other packet type is invalid. */
            default:
                LogError( ( "IotMqtt_DeserializeResponse() called with unknown packet type:(%02x).",
                            ( unsigned int ) pIncomingPacket->type ) );
                status = MQTTBadResponse;
                break;
        }
    }

    return status;
}