File content as of revision 0:11cc2b7889af:

/*
 * Copyright (c) 2015 ARM Limited. All rights reserved.
 * SPDX-License-Identifier: Apache-2.0
 * Licensed under the Apache License, Version 2.0 (the License); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License 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.
 */

// Needed for PRIu64 on FreeRTOS
#include <stdio.h>
// Note: this macro is needed on armcc to get the the PRI*32 macros
// from inttypes.h in a C++ code.
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>

#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include "include/m2minterfaceimpl.h"
#include "include/eventdata.h"
#include "mbed-client/m2minterfaceobserver.h"
#include "mbed-client/m2mconnectionhandler.h"
#include "mbed-client/m2mconnectionsecurity.h"
#include "include/m2mnsdlinterface.h"
#include "mbed-client/m2msecurity.h"
#include "mbed-client/m2mtimer.h"
#include "mbed-trace/mbed_trace.h"
#include "randLIB.h"

#include <stdlib.h>

#define TRACE_GROUP "mClt"

#define RESOLVE_SEC_MODE(mode)  ((mode == M2MInterface::TCP || mode == M2MInterface::TCP_QUEUE) ? M2MConnectionSecurity::TLS : M2MConnectionSecurity::DTLS)

M2MInterfaceImpl::M2MInterfaceImpl(M2MInterfaceObserver& observer,
                                   const String &ep_name,
                                   const String &ep_type,
                                   const int32_t l_time,
                                   const uint16_t listen_port,
                                   const String &dmn,
                                   M2MInterface::BindingMode mode,
                                   M2MInterface::NetworkStack stack,
                                   const String &con_addr)
: _event_data(NULL),
  _registration_flow_timer(NULL),
  _server_port(0),
  _listen_port(listen_port),
  _life_time(l_time),
  _register_server(NULL),
  _queue_sleep_timer(*this),
  _retry_timer(*this),
  _callback_handler(NULL),
  _max_states( STATE_MAX_STATES ),
  _event_ignored(false),
  _event_generated(false),
  _reconnecting(false),
  _retry_timer_expired(false),
  _bootstrapped(true), // True as default to get it working with connector only configuration
  _bootstrap_finished(false),
  _queue_mode_timer_ongoing(false),
  _current_state(0),
  _binding_mode(mode),
  _reconnection_state(M2MInterfaceImpl::None),
  _observer(observer),
  _security_connection( new M2MConnectionSecurity( RESOLVE_SEC_MODE(mode) )),
  _connection_handler(*this, _security_connection, mode, stack),
  _nsdl_interface(*this, _connection_handler),
  _security(NULL)
{
    tr_debug("M2MInterfaceImpl::M2MInterfaceImpl() -IN");
    //TODO:Increase the range from 1 to 100 seconds
    randLIB_seed_random();
    // Range is from 2 to 10
    _initial_reconnection_time = randLIB_get_random_in_range(2, 10);

    tr_info("M2MInterfaceImpl::M2MInterfaceImpl() initial random time %d\n", _initial_reconnection_time);
    _reconnection_time = _initial_reconnection_time;

#ifndef DISABLE_ERROR_DESCRIPTION
    memset(_error_description, 0, sizeof(_error_description));
#endif

    _nsdl_interface.create_endpoint(ep_name,
                                     ep_type,
                                     _life_time,
                                     dmn,
                                     (uint8_t)_binding_mode,
                                     con_addr);

    //Here we must use TCP still
    _connection_handler.bind_connection(_listen_port);

    // We need this timer only in case of TCP
    if (_binding_mode == M2MInterface::TCP ||
        _binding_mode == M2MInterface::TCP_QUEUE ) {
        _registration_flow_timer = new M2MTimer(*this);
    }
    tr_debug("M2MInterfaceImpl::M2MInterfaceImpl() -OUT");
}


M2MInterfaceImpl::~M2MInterfaceImpl()
{
    tr_debug("M2MInterfaceImpl::~M2MInterfaceImpl() - IN");
    delete _registration_flow_timer;
    _security_connection = NULL;
    tr_debug("M2MInterfaceImpl::~M2MInterfaceImpl() - OUT");
}

void M2MInterfaceImpl::bootstrap(M2MSecurity *security)
{
#ifndef MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
    tr_debug("M2MInterfaceImpl::bootstrap - IN - current state %d", _current_state);
    _retry_timer.stop_timer();
    _security = NULL;
    if(!security) {
        set_error_description(ERROR_REASON_1);
        _observer.error(M2MInterface::InvalidParameters);
        return;
    }
    // Transition to a new state based upon
    // the current state of the state machine
    _connection_handler.claim_mutex();
    M2MSecurityData data;
    data._object = security;
    BEGIN_TRANSITION_MAP                                    // - Current State -
        TRANSITION_MAP_ENTRY (STATE_BOOTSTRAP)              // state_idle
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_bootstrap
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state__bootstrap_address_resolved
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_bootstrap_resource_created
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_bootstrap_wait
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_bootstrap_error_wait
        TRANSITION_MAP_ENTRY (STATE_BOOTSTRAP)              // state_bootstrapped
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_register
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_register_address_resolved
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_registered
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_update_registration
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_unregister
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_unregistered
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_sending_coap_data
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_coap_data_sent
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_coap_data_received
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_processing_coap_data
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_coap_data_processed
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_waiting
    END_TRANSITION_MAP(&data)
    if(_event_ignored) {
        _event_ignored = false;
        set_error_description(ERROR_REASON_2);
        _observer.error(M2MInterface::NotAllowed);
    }
    _connection_handler.release_mutex();
    tr_debug("M2MInterfaceImpl::bootstrap - OUT");
#else
    set_error_description(ERROR_REASON_3);
    _observer.error(M2MInterface::NotAllowed);
#endif //MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE

}

void M2MInterfaceImpl::cancel_bootstrap()
{
#ifndef MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
//TODO: Do we need this ?
#endif //MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
}

void M2MInterfaceImpl::finish_bootstrap()
{
#ifndef MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
    tr_debug("M2MInterfaceImpl::finish_bootstrap");
    _security = NULL;
    bootstrap_done();
#endif //MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
}

void M2MInterfaceImpl::register_object(M2MSecurity *security, const M2MObjectList &object_list)
{
    M2MBaseList list;
    M2MObjectList::const_iterator it = object_list.begin();
    for ( ; it != object_list.end(); it++ ) {
        list.push_back(*it);
    }
    register_object(security, list);
}

void M2MInterfaceImpl::register_object(M2MSecurity *security, const M2MBaseList &list)
{
    tr_debug("M2MInterfaceImpl::register_object - IN - current state %d", _current_state);
    if(!security) {
        set_error_description(ERROR_REASON_4);
        _observer.error(M2MInterface::InvalidParameters);
        return;
    }
    // Transition to a new state based upon
    // the current state of the state machine
    //TODO: manage register object in a list.
    _connection_handler.claim_mutex();
    _register_server = security;
    M2MRegisterData data;
    data._object = security;
    data._base_list = list;
    BEGIN_TRANSITION_MAP                                    // - Current State -
        TRANSITION_MAP_ENTRY (STATE_REGISTER)               // state_idle
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_bootstrap
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state__bootstrap_address_resolved
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_bootstrap_resource_created
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_bootstrap_wait
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_bootstrap_error_wait
        TRANSITION_MAP_ENTRY (STATE_REGISTER)               // state_bootstrapped
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_register
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_register_address_resolved
        TRANSITION_MAP_ENTRY (STATE_REGISTER)               // state_registered
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_update_registration
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_unregister
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_unregistered
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_sending_coap_data
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_coap_data_sent
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_coap_data_received
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_processing_coap_data
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_coap_data_processed
        TRANSITION_MAP_ENTRY (STATE_REGISTER)               // state_waiting
    END_TRANSITION_MAP(&data)
    if(_event_ignored) {
        _event_ignored = false;
        set_error_description(ERROR_REASON_5);
        _observer.error(M2MInterface::NotAllowed);
    }
    _connection_handler.release_mutex();
    tr_debug("M2MInterfaceImpl::register_object - OUT");
}

void M2MInterfaceImpl::update_registration(M2MSecurity *security_object, const uint32_t lifetime)
{
    tr_debug("M2MInterfaceImpl::update_registration()");
    _connection_handler.claim_mutex();
    M2MUpdateRegisterData data;
    data._object = security_object;
    data._lifetime = lifetime;
    start_register_update(&data);
    _connection_handler.release_mutex();
}

void M2MInterfaceImpl::update_registration(M2MSecurity *security_object,
                                           const M2MObjectList &object_list,
                                           const uint32_t lifetime)
{
    tr_debug("M2MInterfaceImpl::update_registration - with object list");
    _connection_handler.claim_mutex();
    M2MBaseList list;
    M2MObjectList::const_iterator it = object_list.begin();
    for ( ; it != object_list.end(); it++ ) {
        list.push_back(*it);
    }
    update_registration(security_object, list, lifetime);
    _connection_handler.release_mutex();
}

void M2MInterfaceImpl::update_registration(M2MSecurity *security_object,
                                           const M2MBaseList &list,
                                           const uint32_t lifetime)
{
    tr_debug("M2MInterfaceImpl::update_registration(M2MSecurity *security_object, const M2MObjectList &object_list, const uint32_t lifetime)");
    _connection_handler.claim_mutex();
    M2MUpdateRegisterData data;
    data._object = security_object;
    data._lifetime = lifetime;
    data._base_list = list;
    start_register_update(&data);
    _connection_handler.release_mutex();
}

void M2MInterfaceImpl::unregister_object(M2MSecurity* /*security*/)
{
    tr_debug("M2MInterfaceImpl::unregister_object - IN - current state %d", _current_state);
    if (_nsdl_interface.is_unregister_ongoing()) {
        set_error_description(ERROR_REASON_27);
        _observer.error(M2MInterface::NotAllowed);
        return;
    }

    _connection_handler.claim_mutex();
    // Transition to a new state based upon
    // the current state of the state machine
    BEGIN_TRANSITION_MAP                                // - Current State -
        TRANSITION_MAP_ENTRY (STATE_UNREGISTERED)                // state_idle
        TRANSITION_MAP_ENTRY (STATE_UNREGISTERED)           // state_bootstrap
        TRANSITION_MAP_ENTRY (STATE_UNREGISTERED)           // state__bootstrap_address_resolved
        TRANSITION_MAP_ENTRY (STATE_UNREGISTERED)           // state_bootstrap_resource_created
        TRANSITION_MAP_ENTRY (STATE_UNREGISTERED)           // state_bootstrap_wait
        TRANSITION_MAP_ENTRY (STATE_UNREGISTERED)           // state_bootstrap_error_wait
        TRANSITION_MAP_ENTRY (STATE_UNREGISTERED)           // state_bootstrapped
        TRANSITION_MAP_ENTRY (STATE_UNREGISTERED)           // state_register
        TRANSITION_MAP_ENTRY (STATE_UNREGISTERED)           // state_register_address_resolved
        TRANSITION_MAP_ENTRY (STATE_UNREGISTER)             // state_registered
        TRANSITION_MAP_ENTRY (STATE_UNREGISTER)             // state_update_registration
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_unregister
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_unregistered
        TRANSITION_MAP_ENTRY (STATE_UNREGISTER)             // state_sending_coap_data
        TRANSITION_MAP_ENTRY (STATE_UNREGISTER)             // state_coap_data_sent
        TRANSITION_MAP_ENTRY (STATE_UNREGISTER)             // state_coap_data_received
        TRANSITION_MAP_ENTRY (STATE_UNREGISTER)             // state_processing_coap_data
        TRANSITION_MAP_ENTRY (STATE_UNREGISTER)             // state_coap_data_processed
        TRANSITION_MAP_ENTRY (STATE_UNREGISTER)             // state_waiting
    END_TRANSITION_MAP(NULL)

    _connection_handler.release_mutex();
    tr_debug("M2MInterfaceImpl::unregister_object - OUT");
}

void M2MInterfaceImpl::set_queue_sleep_handler(callback_handler handler)
{
    _callback_handler = handler;
}

void M2MInterfaceImpl::set_random_number_callback(random_number_cb callback)
{
    if(_security_connection) {
        _security_connection->set_random_number_callback(callback);
    }
}

void M2MInterfaceImpl::set_entropy_callback(entropy_cb callback)
{
    if(_security_connection) {
        _security_connection->set_entropy_callback(callback);
    }
}

void M2MInterfaceImpl::set_platform_network_handler(void *handler)
{
    _connection_handler.set_platform_network_handler(handler);
}

void M2MInterfaceImpl::coap_message_ready(uint8_t *data_ptr,
                                          uint16_t data_len,
                                          sn_nsdl_addr_s *address_ptr)
{
    tr_debug("M2MInterfaceImpl::coap_message_ready");
    if (_current_state != STATE_IDLE) {
        internal_event(STATE_SENDING_COAP_DATA);
        if(!_connection_handler.send_data(data_ptr,data_len,address_ptr)) {
            internal_event( STATE_IDLE);
            tr_error("M2MInterfaceImpl::coap_message_ready() - M2MInterface::NetworkError");
            if (!_reconnecting) {
                _queue_mode_timer_ongoing = false;
                socket_error(M2MConnectionHandler::SOCKET_SEND_ERROR, true);
            } else {
                socket_error(M2MConnectionHandler::SOCKET_ABORT);
            }
        }
    }
}

void M2MInterfaceImpl::client_registered(M2MServer *server_object)
{
    tr_info("M2MInterfaceImpl::client_registered");
    internal_event(STATE_REGISTERED);
    //Inform client is registered.
    //TODO: manage register object in a list.
    _observer.object_registered(_register_server,*server_object);
}

void M2MInterfaceImpl::registration_updated(const M2MServer &server_object)
{
    tr_info("M2MInterfaceImpl::registration_updated");
    internal_event(STATE_REGISTERED);
    _observer.registration_updated(_register_server,server_object);
}

void M2MInterfaceImpl::registration_error(uint8_t error_code, bool retry, bool full_registration)
{
    tr_error("M2MInterfaceImpl::registration_error code [%d]", error_code);

    _nsdl_interface.set_registration_status(false);

    // Try to register again
    if (retry) {
        _queue_mode_timer_ongoing = false;

        if (full_registration) {
            _reconnection_state = M2MInterfaceImpl::None;
        } else if (error_code == M2MInterface::UnregistrationFailed) {
            _reconnection_state = M2MInterfaceImpl::Unregistration;
        }

        socket_error(M2MConnectionHandler::SOCKET_SEND_ERROR);
    } else {
        _security = NULL;
        internal_event(STATE_IDLE);
        if (error_code == M2MInterface::UnregistrationFailed) {
            set_error_description(ERROR_REASON_24);
        } else {
            set_error_description(ERROR_REASON_8);
        }
        _observer.error((M2MInterface::Error)error_code);
    }
}

void M2MInterfaceImpl::client_unregistered()
{
    tr_info("M2MInterfaceImpl::client_unregistered()");
    _nsdl_interface.set_registration_status(false);

    // Zero the flag otherwise next registered response will start unregistration process
    _reconnection_state = M2MInterfaceImpl::None;

    internal_event(STATE_UNREGISTERED);
    //TODO: manage register object in a list.
}

void M2MInterfaceImpl::bootstrap_done()
{
#ifndef MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
    tr_info("M2MInterfaceImpl::bootstrap_done");
    _reconnection_time = _initial_reconnection_time;
    _reconnecting = false;
    _reconnection_state = M2MInterfaceImpl::None;
    _bootstrapped = true;

    if (_registration_flow_timer) {
        _registration_flow_timer->stop_timer();
    }

    // Force close connection since either server already closed (sent PEER_CLOSE_NOTIFY)
    // or bootstrap flow has finished.
    _connection_handler.force_close();

    if (_bootstrap_finished) {
        // Inform to observer only if bootstrap has already been finished
        // This has to be done like this since we might get bootstrap_done
        // callback BEFORE bootstrap_finish
        internal_event(STATE_BOOTSTRAPPED);
        _observer.bootstrap_done(_nsdl_interface.get_security_object());
    }
#endif //MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
}

void M2MInterfaceImpl::bootstrap_finish()
{
#ifndef MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
    tr_info("M2MInterfaceImpl::bootstrap_finish");
    internal_event(STATE_BOOTSTRAP_WAIT);
    _observer.bootstrap_data_ready(_nsdl_interface.get_security_object());
    _bootstrap_finished = true;

    if (_bootstrapped) {
        // If _bootstrapped is set, we have already received the bootstrap_done
        // callback so we must inform observer now
        bootstrap_done();
    }
#endif //MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
}

void M2MInterfaceImpl::bootstrap_wait()
{
#ifndef MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
    tr_info("M2MInterfaceImpl::bootstrap_wait");
    internal_event(STATE_BOOTSTRAP_WAIT);
#endif //MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
}

void M2MInterfaceImpl::bootstrap_error_wait(const char *reason)
{
#ifndef MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
    tr_error("M2MInterfaceImpl::bootstrap_error_wait");
    set_error_description(reason);
    internal_event(STATE_BOOTSTRAP_ERROR_WAIT);
#endif //MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
}

void M2MInterfaceImpl::bootstrap_error(const char *reason)
{
#ifndef MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
    tr_error("M2MInterfaceImpl::bootstrap_error(%s)", reason);
    _bootstrapped = false;
    if (_registration_flow_timer) {
        _registration_flow_timer->stop_timer();
    }

    _reconnection_state = M2MInterfaceImpl::None;

    set_error_description(reason);

    _observer.error(M2MInterface::BootstrapFailed);

    internal_event(STATE_IDLE);
    _reconnecting = true;
    _connection_handler.stop_listening();

    _retry_timer_expired = false;
    _retry_timer.start_timer(_reconnection_time * 1000,
                              M2MTimerObserver::RetryTimer);
    tr_info("M2MInterfaceImpl::bootstrap_error - reconnecting in %" PRIu64 "(s)", _reconnection_time);
    _reconnection_time = _reconnection_time * RECONNECT_INCREMENT_FACTOR;
    if(_reconnection_time >= MAX_RECONNECT_TIMEOUT) {
        _reconnection_time = MAX_RECONNECT_TIMEOUT;
    }
#endif //MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
}

void M2MInterfaceImpl::coap_data_processed()
{
    tr_debug("M2MInterfaceImpl::coap_data_processed()");
    internal_event(STATE_COAP_DATA_PROCESSED);
}

void M2MInterfaceImpl::value_updated(M2MBase *base)
{
    tr_debug("M2MInterfaceImpl::value_updated");
    if(base) {
        M2MBase::BaseType type = base->base_type();
        _observer.value_updated(base, type);
    }
}

void M2MInterfaceImpl::data_available(uint8_t* data,
                                      uint16_t data_size,
                                      const M2MConnectionObserver::SocketAddress &address)
{
    tr_debug("M2MInterfaceImpl::data_available");
    ReceivedData event;
    event._data = data;
    event._size = data_size;
    event._address = &address;
    internal_event(STATE_COAP_DATA_RECEIVED, &event);
}

void M2MInterfaceImpl::socket_error(int error_code, bool retry)
{
    // Bootstrap completed once PEER CLOSE notify received from the server.
    if (_current_state == STATE_BOOTSTRAP_WAIT &&
        error_code == M2MConnectionHandler::SSL_PEER_CLOSE_NOTIFY) {
        _security = NULL;
        bootstrap_done();
        return;
    }

    tr_error("M2MInterfaceImpl::socket_error: (%d), retry (%d), reconnecting (%d), reconnection_state (%d)",
             error_code, retry, _reconnecting, (int)_reconnection_state);

    // Ignore errors while client is sleeping
    if (queue_mode()) {
        if (_callback_handler && _queue_mode_timer_ongoing) {
            tr_info("M2MInterfaceImpl::socket_error - Queue Mode - don't try to reconnect while in QueueMode");
            return;
        }
    }
    _queue_sleep_timer.stop_timer();

    if (_registration_flow_timer) {
        _registration_flow_timer->stop_timer();
    }

    const char *error_code_des;
    M2MInterface::Error error = M2MInterface::ErrorNone;
    switch (error_code) {
        case M2MConnectionHandler::SSL_CONNECTION_ERROR:
            error = M2MInterface::SecureConnectionFailed;
            error_code_des = ERROR_SECURE_CONNECTION;
            break;
        case M2MConnectionHandler::DNS_RESOLVING_ERROR:
            error = M2MInterface::DnsResolvingFailed;
            error_code_des = ERROR_DNS;
            break;
        case M2MConnectionHandler::SOCKET_READ_ERROR:
            error = M2MInterface::NetworkError;
            error_code_des = ERROR_NETWORK;
            break;
        case M2MConnectionHandler::SOCKET_SEND_ERROR:
            error = M2MInterface::NetworkError;
            error_code_des = ERROR_NETWORK;
            break;
        case M2MConnectionHandler::SSL_HANDSHAKE_ERROR:
            error = M2MInterface::SecureConnectionFailed;
            error_code_des = ERROR_SECURE_CONNECTION;
            break;
        case M2MConnectionHandler::SOCKET_ABORT:
            error = M2MInterface::NetworkError;
            error_code_des = ERROR_NETWORK;
            break;
        case M2MConnectionHandler::MEMORY_ALLOCATION_FAILED:
            error = M2MInterface::MemoryFail;
            error_code_des = ERROR_NO_MEMORY;
            break;
        case M2MConnectionHandler::FAILED_TO_READ_CREDENTIALS:
            error = M2MInterface::FailedToReadCredentials;
            error_code_des = ERROR_FAILED_TO_READ_CREDENTIALS;
            break;
        default:
            error_code_des = ERROR_NO;
            break;
    }

    internal_event(STATE_IDLE);

    // Do a reconnect
    if (retry) {
        if ((error == M2MInterface::SecureConnectionFailed || error == M2MInterface::InvalidParameters) &&
             _bootstrapped) {
            // Connector client will start the bootstrap flow again
            tr_info("M2MInterfaceImpl::socket_error - goes to re-bootstrap");
            _observer.error(M2MInterface::SecureConnectionFailed);
            return;
        }

        _nsdl_interface.set_request_context_to_be_resend(NULL, 0);
        _reconnecting = true;
        _connection_handler.stop_listening();
        _retry_timer_expired = false;
        _retry_timer.start_timer(_reconnection_time * 1000,
                                 M2MTimerObserver::RetryTimer);

        tr_info("M2MInterfaceImpl::socket_error - reconnecting in %" PRIu64 "(s)", _reconnection_time);

        _reconnection_time = _reconnection_time * RECONNECT_INCREMENT_FACTOR;
        if (_reconnection_time >= MAX_RECONNECT_TIMEOUT) {
            _reconnection_time = MAX_RECONNECT_TIMEOUT;
        }
#ifndef DISABLE_ERROR_DESCRIPTION
        snprintf(_error_description, sizeof(_error_description), ERROR_REASON_9, error_code_des);
#endif
    }
    // Inform application
    if (!retry && M2MInterface::ErrorNone != error) {
        tr_info("M2MInterfaceImpl::socket_error - send error to application");
        _connection_handler.stop_listening();
        _retry_timer.stop_timer();
        _security = NULL;
        _reconnecting = false;
        _reconnection_time = _initial_reconnection_time;
        _reconnection_state = M2MInterfaceImpl::None;
#ifndef DISABLE_ERROR_DESCRIPTION
        snprintf(_error_description, sizeof(_error_description), ERROR_REASON_10, error_code_des);
#endif
    }
    if (M2MInterface::ErrorNone != error) {
        _observer.error(error);
    }
}

void M2MInterfaceImpl::address_ready(const M2MConnectionObserver::SocketAddress &address,
                                     M2MConnectionObserver::ServerType server_type,
                                     const uint16_t server_port)
{
    tr_debug("M2MInterfaceImpl::address_ready");
    ResolvedAddressData data;
    data._address = &address;
    data._port = server_port;
    if( M2MConnectionObserver::Bootstrap == server_type) {
        tr_info("M2MInterfaceImpl::address_ready() Server Type Bootstrap");
        internal_event(STATE_BOOTSTRAP_ADDRESS_RESOLVED, &data);
    } else {
        tr_info("M2MInterfaceImpl::address_ready() Server Type LWM2M");
        internal_event(STATE_REGISTER_ADDRESS_RESOLVED, &data);
    }
}

void M2MInterfaceImpl::data_sent()
{
    tr_debug("M2MInterfaceImpl::data_sent()");
    if(queue_mode()) {
        if(_callback_handler && (_nsdl_interface.is_unregister_ongoing() == false)) {
            _queue_sleep_timer.stop_timer();
            _queue_sleep_timer.start_timer(_nsdl_interface.total_retransmission_time(_nsdl_interface.get_resend_count()) * (uint64_t)1000,
                                            M2MTimerObserver::QueueSleep);
        }
    }

    if (_current_state == STATE_BOOTSTRAP_ERROR_WAIT) {
        // bootstrap_error to be called only after we have sent the last ACK.
        // Otherwise client will goto reconnection mode before ACK has sent.
        bootstrap_error(error_description());
    } else if (_current_state != STATE_BOOTSTRAP_WAIT) {
        internal_event(STATE_COAP_DATA_SENT);
    }

    // Delay the time when CoAP ping will be send.
    _nsdl_interface.calculate_new_coap_ping_send_time();
}

void M2MInterfaceImpl::timer_expired(M2MTimerObserver::Type type)
{
    if (M2MTimerObserver::QueueSleep == type) {
        if (_reconnecting) {
            tr_debug("M2MInterfaceImpl::timer_expired() - reconnection ongoing, continue sleep timer");
            _queue_sleep_timer.start_timer(_nsdl_interface.total_retransmission_time(_nsdl_interface.get_resend_count()) * (uint64_t)1000,
                                            M2MTimerObserver::QueueSleep);
        } else {
            tr_debug("M2MInterfaceImpl::timer_expired() - sleep");
            M2MTimer &timer = _nsdl_interface.get_nsdl_execution_timer();
            timer.stop_timer();
            _queue_mode_timer_ongoing = true;
            if(_callback_handler) {
                _callback_handler();
            }
        }
    } else if (M2MTimerObserver::RetryTimer == type) {
        tr_debug("M2MInterfaceImpl::timer_expired() - retry");
        _retry_timer_expired = true;
        if (_bootstrapped) {
            internal_event(STATE_REGISTER);
        } else {
            internal_event(STATE_BOOTSTRAP);
        }
    } else if (M2MTimerObserver::BootstrapFlowTimer == type) {
#ifndef MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
        tr_debug("M2MInterfaceImpl::timer_expired() - bootstrap");
        _bootstrapped = false;
        if (_registration_flow_timer) {
            _registration_flow_timer->stop_timer();
        }
        bootstrap_error(ERROR_REASON_23);
#endif //MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
    } else if (M2MTimerObserver::RegistrationFlowTimer == type) {
        tr_debug("M2MInterfaceImpl::timer_expired() - register");
        registration_error(M2MInterface::Timeout, true);
    }
}

// state machine sits here.
void M2MInterfaceImpl::state_idle(EventData* /*data*/)
{
    tr_debug("M2MInterfaceImpl::state_idle");
    _nsdl_interface.stop_timers();
    _nsdl_interface.clear_sent_blockwise_messages();
    _nsdl_interface.clear_received_blockwise_messages();
    _queue_sleep_timer.stop_timer();
}

void M2MInterfaceImpl::state_bootstrap(EventData *data)
{
#ifndef MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
    tr_debug("M2MInterfaceImpl::state_bootstrap");
    // Start with bootstrapping preparation
    _bootstrapped = false;
    _bootstrap_finished = false;
    _nsdl_interface.set_registration_status(false);
    M2MSecurityData *event = static_cast<M2MSecurityData *> (data);
    if(!_security) {
        M2MInterface::Error error = M2MInterface::InvalidParameters;
        if (event) {
            _security = event->_object;
            if(_security) {
                int32_t bs_id = _security->get_security_instance_id(M2MSecurity::Bootstrap);
                tr_info("M2MInterfaceImpl::state_bootstrap - bs_id = %" PRId32 "(s)", bs_id);
                if(bs_id >= 0) {
                    String server_address = _security->resource_value_string(M2MSecurity::M2MServerUri, bs_id);
                    _nsdl_interface.set_server_address(server_address.c_str());
                    tr_info("M2MInterfaceImpl::state_bootstrap - server_address %s", server_address.c_str());
                    String coap;
                    if(server_address.compare(0,sizeof(COAP)-1,COAP) == 0) {
                         coap = COAP;
                    }
                    else if(server_address.compare(0,sizeof(COAPS)-1,COAPS) == 0) {
                        _security->resource_value_int(M2MSecurity::SecurityMode, bs_id) != M2MSecurity::NoSecurity ? coap = COAPS: coap = "";
                    }
                    if(!coap.empty()) {
                        server_address = server_address.substr(coap.size(),
                                                           server_address.size()-coap.size());

                        process_address(server_address, _server_ip_address, _server_port);

                        tr_info("M2MInterfaceImpl::state_bootstrap - IP address %s, Port %d", _server_ip_address.c_str(), _server_port);
                        // If bind and resolving server address succeed then proceed else
                        // return error to the application and go to Idle state.
                        if(!_server_ip_address.empty()) {
                            error = M2MInterface::ErrorNone;
                            if (_registration_flow_timer) {
                                _registration_flow_timer->stop_timer();
                                _registration_flow_timer->start_timer(MBED_CLIENT_RECONNECTION_COUNT * MBED_CLIENT_RECONNECTION_INTERVAL * 8 * 1000,
                                                              M2MTimerObserver::BootstrapFlowTimer);
                            }
                            _connection_handler.resolve_server_address(_server_ip_address,
                                                                        _server_port,
                                                                        M2MConnectionObserver::Bootstrap,
                                                                        _security);
                        }
                    }
                }
            }
        }
        if (error != M2MInterface::ErrorNone) {
            tr_error("M2MInterfaceImpl::state_bootstrap - set error as M2MInterface::InvalidParameters");
            internal_event(STATE_IDLE);
            set_error_description(ERROR_REASON_11);
            _observer.error(error);
        }
    } else {
        _listen_port = 0;
        _connection_handler.bind_connection(_listen_port);
        if (_registration_flow_timer) {
            _registration_flow_timer->stop_timer();
            _registration_flow_timer->start_timer(MBED_CLIENT_RECONNECTION_COUNT * MBED_CLIENT_RECONNECTION_INTERVAL * 8 * 1000,
                                          M2MTimerObserver::BootstrapFlowTimer);
        }
        tr_info("M2MInterfaceImpl::state_bootstrap (reconnect) - IP address %s, Port %d", _server_ip_address.c_str(), _server_port);
        _connection_handler.resolve_server_address(_server_ip_address,
                                                    _server_port,
                                                    M2MConnectionObserver::Bootstrap,
                                                    _security);
    }
#endif //MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
}

void M2MInterfaceImpl::state_bootstrap_address_resolved( EventData *data)
{
#ifndef MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
    tr_debug("M2MInterfaceImpl::state_bootstrap_address_resolved");
    if (data) {
        ResolvedAddressData *event = static_cast<ResolvedAddressData *> (data);
        sn_nsdl_addr_s address;

        M2MInterface::NetworkStack stack = event->_address->_stack;

        if(M2MInterface::LwIP_IPv4 == stack) {
            tr_info("M2MInterfaceImpl::state_bootstrap_address_resolved : IPv4 address");
            address.type = SN_NSDL_ADDRESS_TYPE_IPV4;
        } else if((M2MInterface::LwIP_IPv6 == stack) ||
                  (M2MInterface::Nanostack_IPv6 == stack)) {
            tr_info("M2MInterfaceImpl::state_bootstrap_address_resolved : IPv6 address");
            address.type = SN_NSDL_ADDRESS_TYPE_IPV6;
        }
        address.port = event->_port;
        address.addr_ptr = (uint8_t*)event->_address->_address;
        address.addr_len = event->_address->_length;
        _connection_handler.start_listening_for_data();

        if(_nsdl_interface.create_bootstrap_resource(&address)) {
           internal_event(STATE_BOOTSTRAP_RESOURCE_CREATED);
        } else{
            // If resource creation fails then inform error to application
            tr_error("M2MInterfaceImpl::state_bootstrap_address_resolved : M2MInterface::InvalidParameters");
            internal_event(STATE_IDLE);
            set_error_description(ERROR_REASON_12);
            _observer.error(M2MInterface::InvalidParameters);
        }
    }
#endif //MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
}

void M2MInterfaceImpl::state_bootstrap_resource_created( EventData */*data*/)
{
#ifndef MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
    tr_debug("M2MInterfaceImpl::state_bootstrap_resource_created");
#endif //MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
}

void M2MInterfaceImpl::state_bootstrapped( EventData */*data*/)
{
#ifndef MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
    tr_debug("M2MInterfaceImpl::state_bootstrapped");
#endif //MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
}

void M2MInterfaceImpl::state_register(EventData *data)
{
    tr_debug("M2MInterfaceImpl::state_register");
    _nsdl_interface.set_registration_status(false);
    M2MRegisterData *event = static_cast<M2MRegisterData *> (data);
    if (!_security) {
        M2MInterface::Error error = M2MInterface::InvalidParameters;
        // Start with registration preparation
        if(event) {
            _security = event->_object;
            if(_security) {
                int32_t m2m_id = _security->get_security_instance_id(M2MSecurity::M2MServer);
                if(m2m_id >= 0) {
                    if(_nsdl_interface.create_nsdl_list_structure(event->_base_list)) {
                        // If the nsdl resource structure is created successfully
                        String server_address = _security->resource_value_string(M2MSecurity::M2MServerUri, m2m_id);
                        _nsdl_interface.set_server_address(server_address.c_str());
                        tr_info("M2MInterfaceImpl::state_register - server_address %s", server_address.c_str());
                        String  coap;
                        if(server_address.compare(0,sizeof(COAP)-1,COAP) == 0) {
                             coap = COAP;
                        }
                        else if(server_address.compare(0,sizeof(COAPS)-1,COAPS) == 0) {
                            _security->resource_value_int(M2MSecurity::SecurityMode, m2m_id) != M2MSecurity::NoSecurity ? coap = COAPS: coap = "";
                        }
                        if(!coap.empty()) {
                            server_address = server_address.substr(coap.size(),
                                                               server_address.size() - coap.size());
                            process_address(server_address, _server_ip_address, _server_port);

                            tr_info("M2MInterfaceImpl::state_register - IP address %s, Port %d", _server_ip_address.c_str(), _server_port);
                            if(!_server_ip_address.empty()) {
                                // Connection related errors are coming through callback
                                if (_registration_flow_timer) {
                                    _registration_flow_timer->stop_timer();
                                    _registration_flow_timer->start_timer(MBED_CLIENT_RECONNECTION_COUNT * MBED_CLIENT_RECONNECTION_INTERVAL * 8 * 1000,
                                                                  M2MTimerObserver::RegistrationFlowTimer);
                                }
                                error = M2MInterface::ErrorNone;
                                _connection_handler.resolve_server_address(_server_ip_address,_server_port,
                                                                            M2MConnectionObserver::LWM2MServer,
                                                                            _security);
                            }
                        }
                    } else {
                        tr_error("M2MInterfaceImpl::state_register - fail to create nsdl list structure!");
                    }
                }
            }
        }
        if (error != M2MInterface::ErrorNone) {
            tr_error("M2MInterfaceImpl::state_register - set error as M2MInterface::InvalidParameters");
            internal_event(STATE_IDLE);
            set_error_description(ERROR_REASON_13);
            _observer.error(error);
        }
    } else {
        _listen_port = 0;
        if (event) {
            _nsdl_interface.create_nsdl_list_structure(event->_base_list);
        }
        _connection_handler.bind_connection(_listen_port);
        if (_registration_flow_timer) {
            _registration_flow_timer->stop_timer();
            _registration_flow_timer->start_timer(MBED_CLIENT_RECONNECTION_COUNT * MBED_CLIENT_RECONNECTION_INTERVAL * 8 * 1000,
                                          M2MTimerObserver::RegistrationFlowTimer);
        }
        tr_info("M2MInterfaceImpl::state_register (reconnect) - IP address %s, Port %d", _server_ip_address.c_str(), _server_port);
        _connection_handler.resolve_server_address(_server_ip_address,_server_port,
                                                    M2MConnectionObserver::LWM2MServer,
                                                    _security);
    }
}

void M2MInterfaceImpl::process_address(const String& server_address, String& ip_address, uint16_t& port) {

    int colonFound = server_address.find_last_of(':'); //10
    if(colonFound != -1) {
        ip_address = server_address.substr(0,colonFound);
        port = atoi(server_address.substr(colonFound+1,
                                         server_address.size()-ip_address.size()).c_str());
        colonFound = ip_address.find_last_of(']');
        if(ip_address.compare(0,1,"[") == 0) {
            if(colonFound == -1) {
                ip_address.clear();
            } else {
                ip_address = ip_address.substr(1,colonFound-1);
            }
        } else if(colonFound != -1) {
            ip_address.clear();
        }
    }
}

void M2MInterfaceImpl::state_register_address_resolved( EventData *data)
{
    tr_debug("M2MInterfaceImpl::state_register_address_resolved - reconnect status %d", _reconnection_state);
    if(data) {
        ResolvedAddressData *event = static_cast<ResolvedAddressData *> (data);

        sn_nsdl_addr_type_e address_type = SN_NSDL_ADDRESS_TYPE_IPV6;

        M2MInterface::NetworkStack stack = event->_address->_stack;

        if(M2MInterface::LwIP_IPv4 == stack) {
            tr_info("M2MInterfaceImpl::state_register_address_resolved : IPv4 address");
            address_type = SN_NSDL_ADDRESS_TYPE_IPV4;
        } else if((M2MInterface::LwIP_IPv6 == stack) ||
                  (M2MInterface::Nanostack_IPv6 == stack)) {
            tr_info("M2MInterfaceImpl::state_register_address_resolved : IPv6 address");
            address_type = SN_NSDL_ADDRESS_TYPE_IPV6;
        }
        _connection_handler.start_listening_for_data();
        _nsdl_interface.set_server_address((uint8_t*)event->_address->_address,event->_address->_length,
                                           event->_port, address_type);
        switch (_reconnection_state) {
            case M2MInterfaceImpl::None:
                if (!_nsdl_interface.send_register_message()) {
                    // If resource creation fails then inform error to application
                    tr_error("M2MInterfaceImpl::state_register_address_resolved : M2MInterface::MemoryFail");
                    internal_event(STATE_IDLE);
                    set_error_description(ERROR_REASON_25);
                    _observer.error(M2MInterface::MemoryFail);
                }
                break;
            case M2MInterfaceImpl::Unregistration:
            case M2MInterfaceImpl::WithUpdate:
                // Start registration update in case it is reconnection logic because of network issue.
                internal_event(STATE_UPDATE_REGISTRATION);
                break;
        }
    }
}

void M2MInterfaceImpl::state_registered( EventData */*data*/)
{
    tr_info("M2MInterfaceImpl::state_registered");
    if (_registration_flow_timer) {
        _registration_flow_timer->stop_timer();
    }
    _reconnection_time = _initial_reconnection_time;
    _reconnecting = false;
    _nsdl_interface.set_registration_status(true);
    // Continue with the unregistration process if it has failed due to connection lost
    if (_reconnection_state == M2MInterfaceImpl::Unregistration) {
        internal_event(STATE_UNREGISTER);
    } else {
        _reconnection_state = M2MInterfaceImpl::WithUpdate;
    }
}

void M2MInterfaceImpl::state_update_registration(EventData *data)
{
    tr_debug("M2MInterfaceImpl::state_update_registration");
    uint32_t lifetime = 0;
    // Set to false to allow reconnection to work.
    _queue_mode_timer_ongoing = false;

    if (data) {
        M2MUpdateRegisterData *event = static_cast<M2MUpdateRegisterData *> (data);
        // Create new resources if any
        if (!event->_base_list.empty()) {
            _nsdl_interface.create_nsdl_list_structure(event->_base_list);
        }
        lifetime = event->_lifetime;
    }

    bool success = _nsdl_interface.send_update_registration(lifetime);
    if (!success) {
        tr_error("M2MInterfaceImpl::state_update_registration : M2MInterface::MemoryFail");
        internal_event(STATE_IDLE);
        set_error_description(ERROR_REASON_25);
        _observer.error(M2MInterface::MemoryFail);
    }
}

void M2MInterfaceImpl::state_unregister(EventData */*data*/)
{
    tr_debug("M2MInterfaceImpl::state_unregister");
    internal_event(STATE_SENDING_COAP_DATA);
    if(!_nsdl_interface.send_unregister_message()) {
        tr_error("M2MInterfaceImpl::state_unregister : M2MInterface::NotRegistered");
        internal_event(STATE_IDLE);
        set_error_description(ERROR_REASON_16);
        _observer.error(M2MInterface::NotRegistered);
    }
}

void M2MInterfaceImpl::state_unregistered( EventData */*data*/)
{
    tr_info("M2MInterfaceImpl::state_unregistered");
    _reconnection_time = _initial_reconnection_time;
    _connection_handler.force_close();
    _security = NULL;
    _observer.object_unregistered(_register_server);
    internal_event(STATE_IDLE);
}

void M2MInterfaceImpl::state_sending_coap_data( EventData */*data*/)
{
    tr_debug("M2MInterfaceImpl::state_sending_coap_data");
    _nsdl_interface.start_nsdl_execution_timer();
    internal_event(STATE_WAITING);
}

void M2MInterfaceImpl::state_coap_data_sent( EventData */*data*/)
{
    tr_debug("M2MInterfaceImpl::state_coap_data_sent");
    internal_event(STATE_WAITING);
}

void M2MInterfaceImpl::state_coap_data_received(EventData *data)
{
    tr_debug("M2MInterfaceImpl::state_coap_data_received");
    if(data) {
        ReceivedData *event = static_cast<ReceivedData*> (data);
        sn_nsdl_addr_s address;

        M2MInterface::NetworkStack stack = event->_address->_stack;

        if(M2MInterface::LwIP_IPv4 == stack) {
            address.type = SN_NSDL_ADDRESS_TYPE_IPV4;
            address.addr_len = 4;
        } else if((M2MInterface::LwIP_IPv6 == stack) ||
                  (M2MInterface::Nanostack_IPv6 == stack)) {
            address.type = SN_NSDL_ADDRESS_TYPE_IPV6;
            address.addr_len = 16;
        }
        address.port = event->_address->_port;
        address.addr_ptr = (uint8_t*)event->_address->_address;
        address.addr_len = event->_address->_length;

        // Process received data
        internal_event(STATE_PROCESSING_COAP_DATA);
        if(!_nsdl_interface.process_received_data(event->_data,
                                                  event->_size,
                                                  &address)) {
           tr_error("M2MInterfaceImpl::state_coap_data_received : M2MInterface::ResponseParseFailed");
           set_error_description(ERROR_REASON_17);
            _observer.error(M2MInterface::ResponseParseFailed);
        }
    }
}

void M2MInterfaceImpl::state_processing_coap_data( EventData */*data*/)
{
    tr_debug("M2MInterfaceImpl::state_processing_coap_data");
    internal_event(STATE_WAITING);
}

void M2MInterfaceImpl::state_coap_data_processed( EventData */*data*/)
{
    tr_debug("M2MInterfaceImpl::state_coap_data_processed");
    internal_event(STATE_WAITING);
}

void M2MInterfaceImpl::state_waiting( EventData */*data*/)
{
    tr_debug("M2MInterfaceImpl::state_waiting");
}

// generates an external event. called once per external event
// to start the state machine executing
void M2MInterfaceImpl::external_event(uint8_t new_state,
                                     EventData* p_data)
{
    tr_debug("M2MInterfaceImpl::external_event : new state %d", new_state);
    // if we are supposed to ignore this event
    if (new_state == EVENT_IGNORED) {
        tr_debug("M2MInterfaceImpl::external_event : new state is EVENT_IGNORED");
        _event_ignored = true;
    }
    else {
        tr_debug("M2MInterfaceImpl::external_event : handle new state");
        // generate the event and execute the state engine
        internal_event(new_state, p_data);
    }
}

// generates an internal event. called from within a state
// function to transition to a new state
void M2MInterfaceImpl::internal_event(uint8_t new_state,
                                      EventData* p_data)
{
    tr_debug("M2MInterfaceImpl::internal_event : new state %d", new_state);
    _event_data = p_data;
    _event_generated = true;
    _current_state = new_state;
    state_engine();
}

// the state engine executes the state machine states
void M2MInterfaceImpl::state_engine (void)
{
    tr_debug("M2MInterfaceImpl::state_engine");
    EventData* p_data_temp = NULL;

    // while events are being generated keep executing states
    while (_event_generated) {
        p_data_temp = _event_data;  // copy of event data pointer
        _event_data = NULL;       // event data used up, reset ptr
        _event_generated = false;  // event used up, reset flag

        assert(_current_state < _max_states);

        state_function( _current_state, p_data_temp );
    }
}

void M2MInterfaceImpl::state_function( uint8_t current_state, EventData* data )
{
    switch( current_state ) {
        case STATE_IDLE:
            M2MInterfaceImpl::state_idle(data);
            break;
        case STATE_BOOTSTRAP:
        #ifndef MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
            M2MInterfaceImpl::state_bootstrap(data);
        #endif //MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
            break;
        case STATE_BOOTSTRAP_ADDRESS_RESOLVED:
        #ifndef MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
            M2MInterfaceImpl::state_bootstrap_address_resolved(data);
        #endif //MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
            break;
        case STATE_BOOTSTRAP_RESOURCE_CREATED:
        #ifndef MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
            M2MInterfaceImpl::state_bootstrap_resource_created(data);
        #endif //MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
            break;
        case STATE_BOOTSTRAP_WAIT:
        case STATE_BOOTSTRAP_ERROR_WAIT:
        #ifndef MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
            // Do nothing, we're just waiting for data_sent callback
        #endif //MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
            break;
        case STATE_BOOTSTRAPPED:
        #ifndef MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
            M2MInterfaceImpl::state_bootstrapped(data);
        #endif //MBED_CLIENT_DISABLE_BOOTSTRAP_FEATURE
            break;
        case STATE_REGISTER:
            M2MInterfaceImpl::state_register(data);
            break;
        case STATE_REGISTER_ADDRESS_RESOLVED:
            M2MInterfaceImpl::state_register_address_resolved(data);
            break;
        case STATE_REGISTERED:
            M2MInterfaceImpl::state_registered(data);
            break;
        case STATE_UPDATE_REGISTRATION:
            M2MInterfaceImpl::state_update_registration(data);
            break;
        case STATE_UNREGISTER:
            M2MInterfaceImpl::state_unregister(data);
            break;
        case STATE_UNREGISTERED:
            M2MInterfaceImpl::state_unregistered(data);
            break;
        case STATE_SENDING_COAP_DATA:
            M2MInterfaceImpl::state_sending_coap_data(data);
            break;
        case STATE_COAP_DATA_SENT:
            M2MInterfaceImpl::state_coap_data_sent(data);
            break;
        case STATE_COAP_DATA_RECEIVED:
            M2MInterfaceImpl::state_coap_data_received(data);
            break;
        case STATE_PROCESSING_COAP_DATA:
            M2MInterfaceImpl::state_processing_coap_data(data);
            break;
        case STATE_COAP_DATA_PROCESSED:
            M2MInterfaceImpl::state_coap_data_processed(data);
            break;
        case STATE_WAITING:
            M2MInterfaceImpl::state_waiting(data);
            break;
    }
}

void M2MInterfaceImpl::start_register_update(M2MUpdateRegisterData *data) {
    tr_debug("M2MInterfaceImpl::start_register_update()");
    if(!data || (data->_lifetime != 0 && (data->_lifetime < MINIMUM_REGISTRATION_TIME))) {
        set_error_description(ERROR_REASON_18);
        _observer.error(M2MInterface::InvalidParameters);
    }

    if (_reconnecting) {
        //If client is in reconnection mode, ignore this call, state machine will reconnect on its own.
        return;
    } else if (_nsdl_interface.is_update_register_ongoing()) {
        set_error_description(ERROR_REASON_27);
        _observer.error(M2MInterface::NotAllowed);
        return;
    }

    _reconnection_state = M2MInterfaceImpl::WithUpdate;
    BEGIN_TRANSITION_MAP                                    // - Current State -
        TRANSITION_MAP_ENTRY (STATE_REGISTER)                // state_idle
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_bootstrap
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state__bootstrap_address_resolved
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_bootstrap_resource_created
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_bootstrap_wait
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_bootstrap_error_wait
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_bootstrapped
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_register
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_register_address_resolved
        TRANSITION_MAP_ENTRY (STATE_UPDATE_REGISTRATION)    // state_registered
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_update_registration
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_unregister
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_unregistered
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_sending_coap_data
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_coap_data_sent
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_coap_data_received
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_processing_coap_data
        TRANSITION_MAP_ENTRY (EVENT_IGNORED)                // state_coap_data_processed
        TRANSITION_MAP_ENTRY (STATE_UPDATE_REGISTRATION)    // state_waiting
    END_TRANSITION_MAP(data)
    if(_event_ignored) {
        _event_ignored = false;
        if (!_reconnecting) {
            set_error_description(ERROR_REASON_19);
            _observer.error(M2MInterface::NotAllowed);
        }
    }
}

bool M2MInterfaceImpl::remove_object(M2MBase *object)
{
    return _nsdl_interface.remove_object_from_list(object);
}

void M2MInterfaceImpl::update_endpoint(const String &name) {
    _nsdl_interface.update_endpoint(name);
}

void M2MInterfaceImpl::update_domain(const String &domain)
{
    _nsdl_interface.update_domain(domain);
}

const String M2MInterfaceImpl::internal_endpoint_name() const
{
    return _nsdl_interface.internal_endpoint_name();
}

const char *M2MInterfaceImpl::error_description() const
{
#ifndef DISABLE_ERROR_DESCRIPTION
    return _error_description;
#else
    return "";
#endif
}

void M2MInterfaceImpl::set_error_description(const char *description)
{
#ifndef DISABLE_ERROR_DESCRIPTION
    if (strncmp(_error_description, description, sizeof(_error_description)) != 0) {
        strncpy(_error_description, description, MAX_ALLOWED_ERROR_STRING_LENGTH - 1);
    }
#endif
}

bool M2MInterfaceImpl::queue_mode() const
{
    return (_binding_mode == M2MInterface::UDP_QUEUE ||
           _binding_mode == M2MInterface::TCP_QUEUE  ||
           _binding_mode == M2MInterface::SMS_QUEUE  ||
           _binding_mode == M2MInterface::UDP_SMS_QUEUE);
}

void M2MInterfaceImpl::get_data_request(DownloadType type,
                                        const char *uri,
                                        const size_t offset,
                                        const bool async,
                                        get_data_cb data_cb,
                                        get_data_error_cb error_cb,
                                        void *context)
{
    get_data_req_error_e error = FAILED_TO_SEND_MSG;
    if (uri) {
        _nsdl_interface.send_request(type, uri, COAP_MSG_CODE_REQUEST_GET, offset, async, 0, 0, NULL, data_cb, error_cb, context);
    } else {
        error_cb(error, context);
    }
}

void M2MInterfaceImpl::post_data_request(const char *uri,
                                         const bool async,
                                         const uint16_t payload_len,
                                         uint8_t *payload_ptr,
                                         get_data_cb data_cb,
                                         get_data_error_cb error_cb,
                                         void *context)
{
    get_data_req_error_e error = FAILED_TO_SEND_MSG;
    if (uri) {
        _nsdl_interface.send_request(GENERIC_DOWNLOAD, uri, COAP_MSG_CODE_REQUEST_POST, 0, async, 0, payload_len, payload_ptr, data_cb, error_cb, context);
    } else {
        error_cb(error, context);
    }
}

bool M2MInterfaceImpl::set_uri_query_parameters(const char *uri_query_params)
{
    return _nsdl_interface.set_uri_query_parameters(uri_query_params);
}

void M2MInterfaceImpl::pause()
{
    tr_debug("M2MInterfaceImpl::pause");
     _connection_handler.claim_mutex();
    _queue_sleep_timer.stop_timer();
    if (_registration_flow_timer) {
        _registration_flow_timer->stop_timer();
    }
    _connection_handler.unregister_network_handler();
    _nsdl_interface.set_request_context_to_be_resend(NULL, 0);
    _connection_handler.stop_listening();
    _retry_timer.stop_timer();
    _reconnecting = false;
    _reconnection_time = _initial_reconnection_time;
    _reconnection_state = M2MInterfaceImpl::WithUpdate;

    sn_nsdl_clear_coap_resending_queue(_nsdl_interface.get_nsdl_handle());
    internal_event(STATE_IDLE);
     _connection_handler.release_mutex();
}

void M2MInterfaceImpl::resume(void *iface, const M2MBaseList &list)
{
    tr_debug("M2MInterfaceImpl::resume");
    _connection_handler.set_platform_network_handler(iface);
    register_object(_security, list);
}