File content as of revision 0:f9d13e09cf11:

/*******************************************************************************
 *
 * Copyright (c) 2013, 2014 Intel Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v1.0 which accompany this distribution.
 *
 * The Eclipse Public License is available at
 *    http://www.eclipse.org/legal/epl-v10.html
 * The Eclipse Distribution License is available at
 *    http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *    David Navarro, Intel Corporation - initial API and implementation
 *    domedambrosio - Please refer to git log
 *    Fabien Fleutot - Please refer to git log
 *    Simon Bernard - Please refer to git log
 *    Toby Jaffey - Please refer to git log
 *    Manuel Sangoi - Please refer to git log
 *    Julien Vermillard - Please refer to git log
 *
 *******************************************************************************/

/*
 Copyright (c) 2013, 2014 Intel Corporation

 Redistribution and use in source and binary forms, with or without modification,
 are permitted provided that the following conditions are met:

     * Redistributions of source code must retain the above copyright notice,
       this list of conditions and the following disclaimer.
     * Redistributions in binary form must reproduce the above copyright notice,
       this list of conditions and the following disclaimer in the documentation
       and/or other materials provided with the distribution.
     * Neither the name of Intel Corporation nor the names of its contributors
       may be used to endorse or promote products derived from this software
       without specific prior written permission.

 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 THE POSSIBILITY OF SUCH DAMAGE.

 David Navarro <david.navarro@intel.com>

*/

#include "internals.h"

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

#define MAX_LOCATION_LENGTH 10      // strlen("/rd/65534") + 1
#define QUERY_TEMPLATE      "ep="
#define QUERY_LENGTH        3       // strlen("ep=")
#define QUERY_SMS           "sms="
#define QUERY_SMS_LEN       4
#define QUERY_LIFETIME      "lt="
#define QUERY_LIFETIME_LEN  3
#define QUERY_VERSION       "lwm2m="
#define QUERY_VERSION_LEN   6
#define QUERY_BINDING       "b="
#define QUERY_BINDING_LEN   2
#define QUERY_DELIMITER     "&"

#define QUERY_VERSION_FULL      "lwm2m=1.0"
#define QUERY_VERSION_FULL_LEN  9

#ifdef LWM2M_CLIENT_MODE
static void prv_handleRegistrationReply(lwm2m_transaction_t * transacP,
                                        void * message)
{
    lwm2m_server_t * targetP;
    coap_packet_t * packet = (coap_packet_t *)message;

    targetP = (lwm2m_server_t *)(transacP->peerP);

    switch(targetP->status)
    {
    case STATE_REG_PENDING:
    {
        if (packet == NULL)
        {
            targetP->status = STATE_UNKNOWN;
            targetP->mid = 0;
        }
        else if (packet->mid == targetP->mid
              && packet->type == COAP_TYPE_ACK
              && packet->location_path != NULL)
        {
            if (packet->code == CREATED_2_01)
            {
                targetP->status = STATE_REGISTERED;
                targetP->location = coap_get_multi_option_as_string(packet->location_path);
            }
            else if (packet->code == BAD_REQUEST_4_00)
            {
                targetP->status = STATE_UNKNOWN;
                targetP->mid = 0;
            }
        }
    }
    break;
    default:
        break;
    }
}

int lwm2m_register(lwm2m_context_t * contextP)
{
    char query[200];
    char payload[512];
    int payload_length;
    lwm2m_server_t * targetP;
    int remaining;

    payload_length = prv_getRegisterPayload(contextP, payload, sizeof(payload));
    if (payload_length == 0) return INTERNAL_SERVER_ERROR_5_00;

    targetP = contextP->serverList;
    while (targetP != NULL)
    {
        remaining = sizeof(query) - snprintf(query,sizeof(query), "?ep=%s",contextP->endpointName);
        if (remaining <= 1)  return INTERNAL_SERVER_ERROR_5_00;

        if (NULL != targetP->sms) {
            remaining -= QUERY_SMS_LEN + 1 + strlen(targetP->sms);
            if (remaining <= 1)  return INTERNAL_SERVER_ERROR_5_00;

            strcat(query, QUERY_DELIMITER);
            strcat(query, QUERY_SMS);
            strcat(query, targetP->sms);
        }

        if (0 != targetP->lifetime) {
            if (remaining <=17) return INTERNAL_SERVER_ERROR_5_00;
            char lt[16];
            remaining -=sprintf(lt,"&lt=%d",targetP->lifetime);
            strcat(query,lt);
        }

        switch (targetP->binding) {
        case BINDING_U:
            strcat(query,"&b=U");
            break;
        case BINDING_UQ:
            strcat(query,"&b=UQ");
            break;
        case BINDING_S:
            strcat(query,"&b=S");
            break;
        case BINDING_SQ:
            strcat(query,"&b=SQ");
            break;
        case BINDING_US:
            strcat(query,"&b=US");
            break;
        case BINDING_UQS:
            strcat(query,"&b=UQS");
            break;
        default:
            return INTERNAL_SERVER_ERROR_5_00;
        }

        lwm2m_transaction_t * transaction;

        transaction = transaction_new(COAP_POST, NULL, contextP->nextMID++, ENDPOINT_SERVER, (void *)targetP);
        if (transaction == NULL) return INTERNAL_SERVER_ERROR_5_00;

        coap_set_header_uri_path(transaction->message, "/"URI_REGISTRATION_SEGMENT);
        coap_set_header_uri_query(transaction->message, query);
        coap_set_payload(transaction->message, payload, payload_length);

        transaction->callback = prv_handleRegistrationReply;
        transaction->userData = (void *) contextP;

        contextP->transactionList = (lwm2m_transaction_t *)LWM2M_LIST_ADD(contextP->transactionList, transaction);
        if (transaction_send(contextP, transaction) == 0)
        {
            targetP->status = STATE_REG_PENDING;
            targetP->mid = transaction->mID;
        }

        targetP = targetP->next;
    }
    return 0;
}

static void prv_handleRegistrationUpdateReply(lwm2m_transaction_t * transacP,
                                        void * message)
{
    lwm2m_server_t * targetP;
    coap_packet_t * packet = (coap_packet_t *)message;

    targetP = (lwm2m_server_t *)(transacP->peerP);

    switch(targetP->status)
    {
    case STATE_REG_UPDATE_PENDING:
    {
        if (packet == NULL)
        {
            targetP->status = STATE_UNKNOWN;
            targetP->mid = 0;
        }
        else if (packet->mid == targetP->mid
              && packet->type == COAP_TYPE_ACK)
        {
            if (packet->code == CHANGED_2_04)
            {
                targetP->status = STATE_REGISTERED;
            }
            else if (packet->code == BAD_REQUEST_4_00)
            {
                targetP->status = STATE_UNKNOWN;
                targetP->mid = 0;
            }
        }
    }
    break;
    default:
        break;
    }
}

int lwm2m_update_registration(lwm2m_context_t * contextP, uint16_t shortServerID)
{
    // look for the server
    lwm2m_server_t * targetP;
    targetP = contextP->serverList;
    while (targetP != NULL)
    {
        if (targetP->shortID == shortServerID)
        {
            // found the server, trigger the update transaction
            lwm2m_transaction_t * transaction;

            transaction = transaction_new(COAP_PUT, NULL, contextP->nextMID++, ENDPOINT_SERVER, (void *)targetP);
            if (transaction == NULL) return INTERNAL_SERVER_ERROR_5_00;

            coap_set_header_uri_path(transaction->message, targetP->location);

            transaction->callback = prv_handleRegistrationUpdateReply;
            transaction->userData = (void *) contextP;

            contextP->transactionList = (lwm2m_transaction_t *)LWM2M_LIST_ADD(contextP->transactionList, transaction);

            if (transaction_send(contextP, transaction) == 0)
            {
                targetP->status = STATE_REG_UPDATE_PENDING;
                targetP->mid = transaction->mID;
            }
            return 0;
        } else {
            // try next server
            targetP = targetP->next;
        }
    }

    // no server found
    return NOT_FOUND_4_04;
}

static void prv_handleDeregistrationReply(lwm2m_transaction_t * transacP,
                                        void * message)
{
    lwm2m_server_t * targetP;
    coap_packet_t * packet = (coap_packet_t *)message;

    targetP = (lwm2m_server_t *)(transacP->peerP);

    switch(targetP->status)
    {
    case STATE_DEREG_PENDING:
    {
        if (packet == NULL)
        {
            targetP->status = STATE_UNKNOWN;
            targetP->mid = 0;
        }
        else if (packet->mid == targetP->mid
              && packet->type == COAP_TYPE_ACK)
        {
            if (packet->code == DELETED_2_02)
            {
                targetP->status = STATE_UNKNOWN;
            }
            else if (packet->code == BAD_REQUEST_4_00)
            {
                targetP->status = STATE_UNKNOWN;
                targetP->mid = 0;
            }
        }
    }
    break;
    default:
        break;
    }
}

void registration_deregister(lwm2m_context_t * contextP,
                             lwm2m_server_t * serverP)
{
    coap_packet_t message[1];
    uint8_t pktBuffer[COAP_MAX_PACKET_SIZE+1];
    size_t pktBufferLen = 0;

    if (serverP->status == STATE_UNKNOWN
     || serverP->status == STATE_DEREG_PENDING)
        {
            return;
        }

    lwm2m_transaction_t * transaction;
    transaction = transaction_new(COAP_DELETE, NULL, contextP->nextMID++, ENDPOINT_SERVER, (void *)serverP);
    if (transaction == NULL) return;

    coap_set_header_uri_path(transaction->message, serverP->location);

    transaction->callback = prv_handleDeregistrationReply;
    transaction->userData = (void *) contextP;

    contextP->transactionList = (lwm2m_transaction_t *)LWM2M_LIST_ADD(contextP->transactionList, transaction);
    if (transaction_send(contextP, transaction) == 0)
    {
        serverP->status = STATE_REG_PENDING;
        serverP->mid = transaction->mID;
    }
}
#endif

#ifdef LWM2M_SERVER_MODE
static int prv_getParameters(multi_option_t * query,
                             char ** nameP,
                             uint32_t * lifetimeP,
                             char ** msisdnP,
                             lwm2m_binding_t * bindingP)
{
    const char * start;
    int length;

    *nameP = NULL;
    *lifetimeP = 0;
    *msisdnP = NULL;
    *bindingP = BINDING_UNKNOWN;

    while (query != NULL)
    {
        if (strncmp(query->data, QUERY_TEMPLATE, QUERY_LENGTH) == 0)
        {
            if (*nameP != NULL) goto error;
            if (query->len == QUERY_LENGTH) goto error;

            *nameP = (char *)lwm2m_malloc(query->len - QUERY_LENGTH + 1);
            if (*nameP != NULL)
            {
                memcpy(*nameP, query->data + QUERY_LENGTH, query->len - QUERY_LENGTH);
                (*nameP)[query->len - QUERY_LENGTH] = 0;
            }
        }
        else if (strncmp(query->data, QUERY_SMS, QUERY_SMS_LEN) == 0)
        {
            if (*msisdnP != NULL) goto error;
            if (query->len == QUERY_SMS_LEN) goto error;

            *msisdnP = (char *)lwm2m_malloc(query->len - QUERY_SMS_LEN + 1);
            if (*msisdnP != NULL)
            {
                memcpy(*msisdnP, query->data + QUERY_SMS_LEN, query->len - QUERY_SMS_LEN);
                (*msisdnP)[query->len - QUERY_SMS_LEN] = 0;
            }
        }
        else if (strncmp(query->data, QUERY_LIFETIME, QUERY_LIFETIME_LEN) == 0)
        {
            int i;

            if (*lifetimeP != 0) goto error;
            if (query->len == QUERY_LIFETIME_LEN) goto error;

            for (i = QUERY_LIFETIME_LEN ; i < query->len ; i++)
            {
                if (query->data[i] < '0' || query->data[i] > '9') goto error;
                *lifetimeP = (*lifetimeP * 10) + (query->data[i] - '0');
            }
        }
        else if (strncmp(query->data, QUERY_VERSION, QUERY_VERSION_LEN) == 0)
        {
            if ((query->len != QUERY_VERSION_FULL_LEN)
             || (strncmp(query->data, QUERY_VERSION_FULL, QUERY_VERSION_FULL_LEN) != 0))
            {
                goto error;
            }
        }
        else if (strncmp(query->data, QUERY_BINDING, QUERY_BINDING_LEN) == 0)
        {
            if (*bindingP != BINDING_UNKNOWN) goto error;
            if (query->len == QUERY_BINDING_LEN) goto error;

            if (strncmp(query->data + QUERY_BINDING_LEN, "U", query->len - QUERY_BINDING_LEN) == 0)
            {
                *bindingP = BINDING_U;
            }
            else if (strncmp(query->data + QUERY_BINDING_LEN, "UQ", query->len - QUERY_BINDING_LEN) == 0)
            {
                *bindingP = BINDING_UQ;
            }
            else if (strncmp(query->data + QUERY_BINDING_LEN, "S", query->len - QUERY_BINDING_LEN) == 0)
            {
                *bindingP = BINDING_S;
            }
            else if (strncmp(query->data + QUERY_BINDING_LEN, "SQ", query->len - QUERY_BINDING_LEN) == 0)
            {
                *bindingP = BINDING_SQ;
            }
            else if (strncmp(query->data + QUERY_BINDING_LEN, "US", query->len - QUERY_BINDING_LEN) == 0)
            {
                *bindingP = BINDING_UQ;
            }
            else if (strncmp(query->data + QUERY_BINDING_LEN, "UQS", query->len - QUERY_BINDING_LEN) == 0)
            {
                *bindingP = BINDING_UQ;
            }
            else
            {
                goto error;
            }
        }
        query = query->next;
    }

    return 0;

error:
    if (*nameP != NULL) lwm2m_free(*nameP);
    if (*msisdnP != NULL) lwm2m_free(*msisdnP);

    return -1;
}

static int prv_getId(uint8_t * data,
                     uint16_t length,
                     uint16_t * objId,
                     uint16_t * instanceId)
{
    int value;
    uint16_t limit;
    uint16_t end;

    // Expecting application/link-format (RFC6690)
    // strip open and close tags
    if (length >= 1 && data[0] == '<' && data[length-1] == '>')
    {
        data++;
        length-=2;
    } 
    else
    {
        return 0;
    }

    // If there is a preceding /, remove it
    if (length >= 1 && data[0] == '/')
    {
        data++;
        length-=1;
    }

    limit = 0;
    while (limit < length && data[limit] != '/' && data[limit] != ' ') limit++;
    value = prv_get_number(data, limit);
    if (value < 0 || value >= LWM2M_MAX_ID) return 0;
    *objId = value;

    if (limit != length)
    {
        limit += 1;
        end = limit;
        while (end < length && data[end] != ' ') end++;
        if (end != limit)
        {
            value = prv_get_number(data + limit, end - limit);
            if (value >= 0 && value < LWM2M_MAX_ID)
            {
                *instanceId = value;
                return 2;
            }
        }
    }

    return 1;
}

static lwm2m_client_object_t * prv_decodeRegisterPayload(uint8_t * payload,
                                                         uint16_t payloadLength)
{
    lwm2m_client_object_t * objList;
    uint16_t id;
    uint16_t instance;
    uint16_t start;
    uint16_t end;
    int result;

    objList = NULL;
    start = 0;
    while (start < payloadLength)
    {
        while (start < payloadLength && payload[start] == ' ') start++;
        if (start == payloadLength) return objList;
        end = start;
        while (end < payloadLength && payload[end] != ',') end++;
        result = prv_getId(payload + start, end - start, &id, &instance);
        if (result != 0)
        {
            lwm2m_client_object_t * objectP;

            objectP = (lwm2m_client_object_t *)lwm2m_list_find((lwm2m_list_t *)objList, id);
            if (objectP == NULL)
            {
                objectP = (lwm2m_client_object_t *)lwm2m_malloc(sizeof(lwm2m_client_object_t));
                memset(objectP, 0, sizeof(lwm2m_client_object_t));
                if (objectP == NULL) return objList;
                objectP->id = id;
                objList = (lwm2m_client_object_t *)LWM2M_LIST_ADD(objList, objectP);
            }
            if (result == 2)
            {
                lwm2m_list_t * instanceP;

                instanceP = lwm2m_list_find(objectP->instanceList, instance);
                if (instanceP == NULL)
                {
                    instanceP = (lwm2m_list_t *)lwm2m_malloc(sizeof(lwm2m_list_t));
                    memset(instanceP, 0, sizeof(lwm2m_list_t));
                    instanceP->id = instance;
                    objectP->instanceList = LWM2M_LIST_ADD(objectP->instanceList, instanceP);
                }
            }
        }
        start = end + 1;
    }

    return objList;
}

static lwm2m_client_t * prv_getClientByName(lwm2m_context_t * contextP,
                                            char * name)
{
    lwm2m_client_t * targetP;

    targetP = contextP->clientList;
    while (targetP != NULL && strcmp(name, targetP->name) != 0)
    {
        targetP = targetP->next;
    }

    return targetP;
}

static void prv_freeClientObjectList(lwm2m_client_object_t * objects)
{
    while (objects != NULL)
    {
        lwm2m_client_object_t * objP;

        while (objects->instanceList != NULL)
        {
            lwm2m_list_t * target;

            target = objects->instanceList;
            objects->instanceList = objects->instanceList->next;
            lwm2m_free(target);
        }

        objP = objects;
        objects = objects->next;
        lwm2m_free(objP);
    }
}

void prv_freeClient(lwm2m_client_t * clientP)
{
    if (clientP->name != NULL) lwm2m_free(clientP->name);
    if (clientP->msisdn != NULL) lwm2m_free(clientP->msisdn);
    prv_freeClientObjectList(clientP->objectList);
    while(clientP->observationList != NULL)
    {
        lwm2m_observation_t * targetP;

        targetP = clientP->observationList;
        clientP->observationList = clientP->observationList->next;
        lwm2m_free(targetP);
    }
    lwm2m_free(clientP);
}

static int prv_getLocationString(uint16_t id,
                                 char location[MAX_LOCATION_LENGTH])
{
    int result;

    memset(location, 0, MAX_LOCATION_LENGTH);

    result = snprintf(location, MAX_LOCATION_LENGTH, "/"URI_REGISTRATION_SEGMENT"/%hu", id);
    if (result <= 0 || result > MAX_LOCATION_LENGTH)
    {
        return 0;
    }

    return result;
}

coap_status_t handle_registration_request(lwm2m_context_t * contextP,
                                          lwm2m_uri_t * uriP,
                                          void * fromSessionH,
                                          coap_packet_t * message,
                                          coap_packet_t * response)
{
    coap_status_t result;
    struct timeval tv;

    if (lwm2m_gettimeofday(&tv, NULL) != 0)
    {
        return COAP_500_INTERNAL_SERVER_ERROR;
    }

    switch(message->code)
    {
    case COAP_POST:
    {
        char * name = NULL;
        uint32_t lifetime;
        char * msisdn;
        lwm2m_binding_t binding;
        lwm2m_client_object_t * objects;
        lwm2m_client_t * clientP;
        char location[MAX_LOCATION_LENGTH];

        if ((uriP->flag & LWM2M_URI_MASK_ID) != 0) return COAP_400_BAD_REQUEST;
        if (0 != prv_getParameters(message->uri_query, &name, &lifetime, &msisdn, &binding))
        {
            return COAP_400_BAD_REQUEST;
        }
        objects = prv_decodeRegisterPayload(message->payload, message->payload_len);
        if (objects == NULL)
        {
            lwm2m_free(name);
            if (msisdn != NULL) lwm2m_free(msisdn);
            return COAP_400_BAD_REQUEST;
        }
        // Endpoint client name is mandatory
        if (name == NULL)
        {
            if (msisdn != NULL) lwm2m_free(msisdn);
            return COAP_400_BAD_REQUEST;
        }
        if (lifetime == 0)
        {
            lifetime = LWM2M_DEFAULT_LIFETIME;
        }

        clientP = prv_getClientByName(contextP, name);
        if (clientP != NULL)
        {
            // we reset this registration
            lwm2m_free(clientP->name);
            if (clientP->msisdn != NULL) lwm2m_free(clientP->msisdn);
            prv_freeClientObjectList(clientP->objectList);
            clientP->objectList = NULL;
        }
        else
        {
            clientP = (lwm2m_client_t *)lwm2m_malloc(sizeof(lwm2m_client_t));
            if (clientP == NULL)
            {
                lwm2m_free(name);
                if (msisdn != NULL) lwm2m_free(msisdn);
                prv_freeClientObjectList(objects);
                return COAP_500_INTERNAL_SERVER_ERROR;
            }
            memset(clientP, 0, sizeof(lwm2m_client_t));
            clientP->internalID = lwm2m_list_newId((lwm2m_list_t *)contextP->clientList);
            contextP->clientList = (lwm2m_client_t *)LWM2M_LIST_ADD(contextP->clientList, clientP);
        }
        clientP->name = name;
        clientP->binding = binding;
        clientP->msisdn = msisdn;
        clientP->lifetime = lifetime;
        clientP->endOfLife = tv.tv_sec + lifetime;
        clientP->objectList = objects;
        clientP->sessionH = fromSessionH;

        if (prv_getLocationString(clientP->internalID, location) == 0)
        {
            prv_freeClient(clientP);
            return COAP_500_INTERNAL_SERVER_ERROR;
        }
        if (coap_set_header_location_path(response, location) == 0)
        {
            prv_freeClient(clientP);
            return COAP_500_INTERNAL_SERVER_ERROR;
        }

        if (contextP->monitorCallback != NULL)
        {
            contextP->monitorCallback(clientP->internalID, NULL, CREATED_2_01, NULL, 0, contextP->monitorUserData);
        }
        result = COAP_201_CREATED;
    }
    break;

    case COAP_PUT:
    {
        char * name = NULL;
        uint32_t lifetime;
        char * msisdn;
        lwm2m_binding_t binding;
        lwm2m_client_object_t * objects;
        lwm2m_client_t * clientP;

        if ((uriP->flag & LWM2M_URI_MASK_ID) != LWM2M_URI_FLAG_OBJECT_ID) return COAP_400_BAD_REQUEST;

        clientP = (lwm2m_client_t *)lwm2m_list_find((lwm2m_list_t *)contextP->clientList, uriP->objectId);
        if (clientP == NULL) return COAP_404_NOT_FOUND;

        if (0 != prv_getParameters(message->uri_query, &name, &lifetime, &msisdn, &binding))
        {
            return COAP_400_BAD_REQUEST;
        }
        objects = prv_decodeRegisterPayload(message->payload, message->payload_len);

        // Endpoint client name MUST NOT be present
        if (name != NULL)
        {
            lwm2m_free(name);
            if (msisdn != NULL) lwm2m_free(msisdn);
            return COAP_400_BAD_REQUEST;
        }

        if (binding != BINDING_UNKNOWN)
        {
            clientP->binding = binding;
        }
        if (msisdn != NULL)
        {
            if (clientP->msisdn != NULL) lwm2m_free(clientP->msisdn);
            clientP->msisdn = msisdn;
        }
        if (lifetime != 0)
        {
            clientP->lifetime = lifetime;
        }
        // client IP address, port or MSISDN may have changed
        clientP->sessionH = fromSessionH;

        if (objects != NULL)
        {
            lwm2m_observation_t * observationP;

            // remove observations on object/instance no longer existing
            observationP = clientP->observationList;
            while (observationP != NULL)
            {
                lwm2m_client_object_t * objP;
                lwm2m_observation_t * nextP;

                nextP = observationP->next;

                objP = (lwm2m_client_object_t *)lwm2m_list_find((lwm2m_list_t *)objects, observationP->uri.objectId);
                if (objP == NULL)
                {
                    observationP->callback(clientP->internalID,
                                           &observationP->uri,
                                           COAP_202_DELETED,
                                           NULL, 0,
                                           observationP->userData);
                    observation_remove(clientP, observationP);
                }
                else
                {
                    if ((observationP->uri.flag & LWM2M_URI_FLAG_INSTANCE_ID) != 0)
                    {
                        if (lwm2m_list_find((lwm2m_list_t *)objP->instanceList, observationP->uri.instanceId) == NULL)
                        {
                            observationP->callback(clientP->internalID,
                                                   &observationP->uri,
                                                   COAP_202_DELETED,
                                                   NULL, 0,
                                                   observationP->userData);
                            observation_remove(clientP, observationP);
                        }
                    }
                }

                observationP = nextP;
            }

            prv_freeClientObjectList(clientP->objectList);
            clientP->objectList = objects;
        }

        clientP->endOfLife = tv.tv_sec + clientP->lifetime;

        if (contextP->monitorCallback != NULL)
        {
            contextP->monitorCallback(clientP->internalID, NULL, COAP_204_CHANGED, NULL, 0, contextP->monitorUserData);
        }
        result = COAP_204_CHANGED;
    }
    break;

    case COAP_DELETE:
    {
        lwm2m_client_t * clientP;

        if ((uriP->flag & LWM2M_URI_MASK_ID) != LWM2M_URI_FLAG_OBJECT_ID) return COAP_400_BAD_REQUEST;

        contextP->clientList = (lwm2m_client_t *)LWM2M_LIST_RM(contextP->clientList, uriP->objectId, &clientP);
        if (clientP == NULL) return COAP_400_BAD_REQUEST;
        if (contextP->monitorCallback != NULL)
        {
            contextP->monitorCallback(clientP->internalID, NULL, DELETED_2_02, NULL, 0, contextP->monitorUserData);
        }
        prv_freeClient(clientP);
        result = COAP_202_DELETED;
    }
    break;

    default:
        return COAP_400_BAD_REQUEST;
    }

    return result;
}

void lwm2m_set_monitoring_callback(lwm2m_context_t * contextP,
                                   lwm2m_result_callback_t callback,
                                   void * userData)
{
    contextP->monitorCallback = callback;
    contextP->monitorUserData = userData;
}


#endif