text: /*
   * Copyright (c) 2015-2018, Yanzi Networks AB.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. 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.
   * 3. Neither the name of the copyright holder 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 HOLDER 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 HOLDER 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.
   */
  
  /**
   * \addtogroup lwm2m
   * @{
   *
   */
  
  /**
   * \file
   *         Implementation of the Contiki OMA LWM2M server
   * \author
   *         Joakim Eriksson <joakime@sics.se>
   *         Niclas Finne <nfi@sics.se>
   */
  
  #include <stdint.h>
  #include "lib/list.h"
  #include "lwm2m-object.h"
  #include "lwm2m-engine.h"
  #include "lwm2m-server.h"
  #include "lwm2m-rd-client.h"
  
  /* Log configuration */
  #include "coap-log.h"
  #define LOG_MODULE "lwm2m-srv"
  #define LOG_LEVEL  LOG_LEVEL_LWM2M
  
  #define MAX_COUNT LWM2M_SERVER_MAX_COUNT
  
  static lwm2m_status_t lwm2m_callback(lwm2m_object_instance_t *object,
                                       lwm2m_context_t *ctx);
  
  static lwm2m_object_instance_t *create_instance(uint16_t instance_id,
                                                  lwm2m_status_t *status);
  static int delete_instance(uint16_t instance_id, lwm2m_status_t *status);
  static lwm2m_object_instance_t *get_first(lwm2m_status_t *status);
  static lwm2m_object_instance_t *get_next(lwm2m_object_instance_t *instance,
                                           lwm2m_status_t *status);
  static lwm2m_object_instance_t *get_by_id(uint16_t instance_id,
                                            lwm2m_status_t *status);
  
  static const lwm2m_resource_id_t resources[] = {
    RO(LWM2M_SERVER_SHORT_SERVER_ID),
    RW(LWM2M_SERVER_LIFETIME_ID),
    EX(LWM2M_SERVER_REG_UPDATE_TRIGGER_ID)
  };
  
  static const lwm2m_object_impl_t impl = {
    .object_id = LWM2M_OBJECT_SERVER_ID,
    .get_first = get_first,
    .get_next = get_next,
    .get_by_id = get_by_id,
    .create_instance = create_instance,
    .delete_instance = delete_instance,
  };
  static lwm2m_object_t server_object = {
    .impl = &impl,
  };
  
  LIST(server_list);
  static lwm2m_server_t server_instances[MAX_COUNT];
  /*---------------------------------------------------------------------------*/
  static lwm2m_object_instance_t *
  create_instance(uint16_t instance_id, lwm2m_status_t *status)
  {
    lwm2m_object_instance_t *instance;
    int i;
  
    instance = get_by_id(instance_id, NULL);
    if(instance != NULL) {
      /* An instance with this id is already registered */
      if(status) {
        *status = LWM2M_STATUS_OPERATION_NOT_ALLOWED;
      }
      return NULL;
    }
  
    for(i = 0; i < MAX_COUNT; i++) {
      if(server_instances[i].instance.instance_id == LWM2M_OBJECT_INSTANCE_NONE) {
        server_instances[i].instance.callback = lwm2m_callback;
        server_instances[i].instance.object_id = LWM2M_OBJECT_SERVER_ID;
        server_instances[i].instance.instance_id = instance_id;
        server_instances[i].instance.resource_ids = resources;
        server_instances[i].instance.resource_count =
          sizeof(resources) / sizeof(lwm2m_resource_id_t);
        server_instances[i].server_id = 0;
        server_instances[i].lifetime = 0;
        list_add(server_list, &server_instances[i].instance);
  
        if(status) {
          *status = LWM2M_STATUS_OK;
        }
  
        return &server_instances[i].instance;
      }
    }
  
    if(status) {
      *status = LWM2M_STATUS_SERVICE_UNAVAILABLE;
    }
  
    return NULL;
  }
  /*---------------------------------------------------------------------------*/
  static int
  delete_instance(uint16_t instance_id, lwm2m_status_t *status)
  {
    lwm2m_object_instance_t *instance;
  
    if(status) {
      *status = LWM2M_STATUS_OK;
    }
  
    if(instance_id == LWM2M_OBJECT_INSTANCE_NONE) {
      /* Remove all instances */
      while((instance = list_pop(server_list)) != NULL) {
        instance->instance_id = LWM2M_OBJECT_INSTANCE_NONE;
      }
      return 1;
    }
  
    instance = get_by_id(instance_id, NULL);
    if(instance != NULL) {
      instance->instance_id = LWM2M_OBJECT_INSTANCE_NONE;
      list_remove(server_list, instance);
      return 1;
    }
  
    return 0;
  }
  /*---------------------------------------------------------------------------*/
  static lwm2m_object_instance_t *
  get_first(lwm2m_status_t *status)
  {
    if(status) {
      *status = LWM2M_STATUS_OK;
    }
    return list_head(server_list);
  }
  /*---------------------------------------------------------------------------*/
  static lwm2m_object_instance_t *
  get_next(lwm2m_object_instance_t *instance, lwm2m_status_t *status)
  {
    if(status) {
      *status = LWM2M_STATUS_OK;
    }
    return instance == NULL ? NULL : instance->next;
  }
  /*---------------------------------------------------------------------------*/
  static lwm2m_object_instance_t *
  get_by_id(uint16_t instance_id, lwm2m_status_t *status)
  {
    lwm2m_object_instance_t *instance;
    if(status) {
      *status = LWM2M_STATUS_OK;
    }
    for(instance = list_head(server_list);
        instance != NULL;
        instance = instance->next) {
      if(instance->instance_id == instance_id) {
        return instance;
      }
    }
    return NULL;
  }
  /*---------------------------------------------------------------------------*/
  static lwm2m_status_t
  lwm2m_callback(lwm2m_object_instance_t *object,
                 lwm2m_context_t *ctx)
  {
    int32_t value;
    lwm2m_server_t *server;
    server = (lwm2m_server_t *) object;
  
    if(ctx->operation == LWM2M_OP_WRITE) {
      LOG_DBG("Write to: %d\n", ctx->resource_id);
      switch(ctx->resource_id) {
      case LWM2M_SERVER_LIFETIME_ID:
        lwm2m_object_read_int(ctx, ctx->inbuf->buffer, ctx->inbuf->size, &value);
        server->lifetime = value;
        break;
      }
    } else if(ctx->operation == LWM2M_OP_READ) {
      switch(ctx->resource_id) {
      case LWM2M_SERVER_SHORT_SERVER_ID:
        lwm2m_object_write_int(ctx, server->server_id);
        break;
      case LWM2M_SERVER_LIFETIME_ID:
        lwm2m_object_write_int(ctx, server->lifetime);
        break;
      }
    } else if(ctx->operation == LWM2M_OP_EXECUTE) {
      switch(ctx->resource_id) {
      case LWM2M_SERVER_REG_UPDATE_TRIGGER_ID:
        lwm2m_rd_client_update_triggered(ctx->request->src_ep);
        break;
      }
    } else {
      return LWM2M_STATUS_NOT_IMPLEMENTED;
    }
  
    return LWM2M_STATUS_OK;
  }
  /*---------------------------------------------------------------------------*/
  lwm2m_server_t *
  lwm2m_server_add(uint16_t instance_id, uint16_t server_id, uint32_t lifetime)
  {
    lwm2m_server_t *server;
    int i;
  
    for(server = list_head(server_list);
        server;
        server = (lwm2m_server_t *)server->instance.next) {
      if(server->server_id == server_id) {
        /* Found a matching server */
        if(server->instance.instance_id != instance_id) {
          /* Non-matching instance id */
          LOG_DBG("non-matching instance id for server %u\n", server_id);
          return NULL;
        }
        server->lifetime = lifetime;
        return server;
      } else if(server->instance.instance_id == instance_id) {
        /* Right instance but wrong server id */
        LOG_DBG("non-matching server id for instance %u\n", instance_id);
        return NULL;
      }
    }
  
    for(i = 0; i < MAX_COUNT; i++) {
      if(server_instances[i].instance.instance_id == LWM2M_OBJECT_INSTANCE_NONE) {
        server_instances[i].instance.callback = lwm2m_callback;
        server_instances[i].instance.object_id = LWM2M_OBJECT_SERVER_ID;
        server_instances[i].instance.instance_id = instance_id;
        server_instances[i].instance.resource_ids = resources;
        server_instances[i].instance.resource_count =
          sizeof(resources) / sizeof(lwm2m_resource_id_t);
        server_instances[i].server_id = server_id;
        server_instances[i].lifetime = lifetime;
        list_add(server_list, &server_instances[i].instance);
  
        return &server_instances[i];
      }
    }
  
    LOG_WARN("no space for more servers\n");
  
    return NULL;
  }
  /*---------------------------------------------------------------------------*/
  void
  lwm2m_server_init(void)
  {
    int i;
  
    LOG_INFO("init\n");
  
    list_init(server_list);
  
    for(i = 0; i < MAX_COUNT; i++) {
      server_instances[i].instance.instance_id = LWM2M_OBJECT_INSTANCE_NONE;
    }
    lwm2m_engine_add_generic_object(&server_object);
  }
  /*---------------------------------------------------------------------------*/
  /** @} */
  