text: /* Copyright (c) 2016 Nordic Semiconductor. All Rights Reserved.
   *
   * The information contained herein is property of Nordic Semiconductor ASA.
   * Terms and conditions of usage are described in detail in NORDIC
   * SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT.
   *
   * Licensees are granted free, non-transferable use of the information. NO
   * WARRANTY of ANY KIND is provided. This heading must NOT be removed from
   * the file.
   *
   */
  
  #include "es_slot.h"
  #include "es_slot_reg.h"
  #include "es_app_config.h"
  #include "nrf_error.h"
  #include "ble_gap.h"
  #include "es_security.h"
  #include "es_flash.h"
  #include "es_tlm.h"
  #include <stdint.h>
  #include <string.h>
  #include "fds.h"
  
  static es_slot_reg_t m_reg;             //!< Slot registry.
  static bool m_eid_loaded_from_flash;    //!< Set to true if EID slot has been loaded from flash.
  
  #define RANGING_DATA_INDEX  (1)         //!< Index of ranging data within frames that contain ranging data.
  #define RANGING_DATA_LENGTH (1)         //!< Length of ranging data.
  
  /**@brief Enforce legal slot number.
   *
   * @param[in] p_slot Pointer to the slot number variable to check.
   */
  static void slot_boundary_check(uint8_t * p_slot)
  {
      if (*p_slot > (APP_MAX_ADV_SLOTS - 1))
      {
          *p_slot = (APP_MAX_ADV_SLOTS - 1);
      }
  }
  
  
  /**@brief Function loading slot data from flash.
   *
   * @param[in] slot_no       Slot number to be used.
   */
  static void load_slot_from_flash(uint8_t slot_no)
  {
      ret_code_t err_code;
  
      err_code = es_flash_access_slot_configs(slot_no,
                                              &m_reg.slots[slot_no],
                                              ES_FLASH_ACCESS_READ);
      if (err_code != FDS_ERR_NOT_FOUND)
      {
          APP_ERROR_CHECK(err_code);
  
          if (m_reg.slots[slot_no].adv_frame.type == ES_FRAME_TYPE_EID)
          {
              m_eid_loaded_from_flash = true;
              
              es_security_eid_slots_restore(slot_no,
                                            m_reg.slots[slot_no].k_scaler,
                                            m_reg.slots[slot_no].seconds,
                                            (const uint8_t *)m_reg.slots[slot_no].ik);
          }
  
          else
          {
              // If a non-EID slot has been loaded, update the state of m_reg immediately.
              es_slot_reg_update_slot_list_info_on_add(&m_reg, slot_no, m_reg.slots[slot_no].adv_frame.type, true);
          }
  
      }
  }
  
  
  /**@brief Function for setting the ranging data field to be broadcast in the frame.
   *
   * @param[in]       slot_no         The slot index.
   * @param[in]       tx_power        The radio tx power to be calibrated to ranging data.
   */
  static void set_ranging_data_for_slot(uint8_t slot_no, nrf_ble_escs_radio_tx_pwr_t tx_power)
  {
      int8_t ranging_data_array[ESCS_NUM_OF_SUPPORTED_TX_POWER] =
          APP_CONFIG_CALIBRATED_RANGING_DATA;
      nrf_ble_escs_radio_tx_pwr_t supported_tx[ESCS_NUM_OF_SUPPORTED_TX_POWER] =
          ESCS_SUPPORTED_TX_POWER;
  
      int8_t ranging_data = 0;
  
      if (m_reg.slots[slot_no].adv_custom_tx_power)
      {
          ranging_data = m_reg.slots[slot_no].custom_tx_power;
      }
  
      else
      {
          for (uint8_t i = 0; i < ESCS_NUM_OF_SUPPORTED_TX_POWER; i++)
          {
              if (supported_tx[i] >= tx_power)
              {
                  ranging_data = ranging_data_array[i];
                  break;
              }
          }
      }
  
      uint8_t * p_ranging_data = ((uint8_t *)(&m_reg.slots[slot_no].adv_frame.frame) + 1);
      *p_ranging_data = ranging_data;
  }
  
  
  /**@brief Function configuring a non-EID slot.
   *
   * @param[in] slot_no       Slot number to be used.
   * @param[in] length        Length of write operation.
   * @param[in] p_frame_data  Pointer to written data.
   */
  static void configure_slot(uint8_t slot_no, uint8_t length, uint8_t * p_frame_data)
  {
      // If a TLM slot is being configured and there already exists a TLM.
      if ((es_frame_type_t)p_frame_data[0] == ES_FRAME_TYPE_TLM && m_reg.tlm_configured)
      {
          return; // Silently ignore any attempts to create more than one TLM slot as there is no point.
      }
  
      es_slot_reg_update_slot_list_info_on_add(&m_reg, slot_no, (es_frame_type_t)p_frame_data[0], false);
  
      // For convenience, frame_type is stored in two places, set both.
      m_reg.slots[slot_no].adv_frame.type = (es_frame_type_t)p_frame_data[0];
      memcpy(&m_reg.slots[slot_no].adv_frame.frame, &m_reg.slots[slot_no].adv_frame.type, 1);
  
      uint8_t * p_data_after_ranging_data = \
          ((uint8_t *)(&m_reg.slots[slot_no].adv_frame.frame) + RANGING_DATA_INDEX + RANGING_DATA_LENGTH);
  
      switch (m_reg.slots[slot_no].adv_frame.type)
      {
          case ES_FRAME_TYPE_UID:
              // Fall through.
          case ES_FRAME_TYPE_URL:
              memcpy(p_data_after_ranging_data, &p_frame_data[1], length);
              set_ranging_data_for_slot(slot_no, APP_CFG_DEFAULT_RADIO_TX_POWER);
              m_reg.slots[slot_no].adv_frame.length = length + 1; // + 1 for ranging data
              break;
  
          case ES_FRAME_TYPE_TLM:
              es_tlm_tlm_get(&m_reg.slots[slot_no].adv_frame.frame.tlm);
              m_reg.slots[slot_no].adv_frame.length = ES_TLM_LENGTH;
              break;
  
          default:
              break;
      }
  }
  
  
  /**@brief Function configuring an EID slot.
   *
   * @param[in] slot_no       Slot number to be used.
   * @param[in] length        Length of write operation.
   * @param[in] p_frame_data  Pointer to written data.
   */
  static void configure_eid_slot(uint8_t slot_no, uint8_t length, uint8_t * p_frame_data)
  {
      ret_code_t err_code;
      bool clear_eid_slot = false;
      
      // Do not update slot count, as this will be done when in the callback invoked when the EID data is ready.
      // As it takes a while to do the calculation, temporarily remove the slot being overwritten.
      // The slot will be re-added in the callback invoked when the EID data is ready.
      clear_eid_slot = es_slot_reg_clear_slot(&m_reg, slot_no);
      
      if(clear_eid_slot)
      {
          es_security_eid_slot_destroy(slot_no);
      }
  
      if (p_frame_data[0] != ES_FRAME_TYPE_EID)
      {
          APP_ERROR_CHECK(NRF_ERROR_INVALID_STATE);
      }
  
      if (length == ESCS_EID_WRITE_ECDH_LENGTH)
      {
          err_code = es_security_client_pub_ecdh_receive(slot_no, 
                                                        &p_frame_data[ESCS_EID_WRITE_PUB_KEY_INDEX], 
                                                         p_frame_data[ESCS_EID_WRITE_ECDH_LENGTH -1]);
          APP_ERROR_CHECK(err_code);
      }
  
      else if (length == ESCS_EID_WRITE_IDK_LENGTH)
      {
          es_security_shared_ik_receive(slot_no, 
                                       &p_frame_data[ESCS_EID_WRITE_ENC_ID_KEY_INDEX], 
                                        p_frame_data[ESCS_EID_WRITE_IDK_LENGTH - 1]);
      }
      
      else
      {
          // Invalid length being written.
          APP_ERROR_CHECK(NRF_ERROR_INVALID_PARAM);
      }
  }
  
  
  ret_code_t es_slot_write_to_flash(uint8_t slot_no)
  {
      if (m_reg.slots[slot_no].configured)
      {
          // If its an EID, we need to store some metadata in order to re-initialize the EID.
          if (m_reg.slots[slot_no].adv_frame.type == ES_FRAME_TYPE_EID)
          {
              m_reg.slots[slot_no].seconds  = es_security_clock_get(slot_no);
              m_reg.slots[slot_no].k_scaler = es_security_scaler_get(slot_no);
              es_security_encrypted_eid_id_key_get(slot_no, m_reg.slots[slot_no].ik);
          }
          return es_flash_access_slot_configs(slot_no,
                                              &m_reg.slots[slot_no],
                                              ES_FLASH_ACCESS_WRITE);
      }
  
      else
      {
          return es_flash_access_slot_configs(slot_no,
                                              NULL,
                                              ES_FLASH_ACCESS_CLEAR);
      }
  }
  
  
  void es_slot_radio_tx_pwr_set(uint8_t slot_no, nrf_ble_escs_radio_tx_pwr_t radio_tx_pwr)
  {
      slot_boundary_check(&slot_no);
  
      m_reg.slots[slot_no].radio_tx_pwr = radio_tx_pwr;
  
      if (!m_reg.slots[slot_no].adv_custom_tx_power) // Only update TX power in ADV if custom TX power is not set
      {
          set_ranging_data_for_slot(slot_no, radio_tx_pwr);
      }
  }
  
  
  void es_slot_set_adv_custom_tx_power(uint8_t slot_no, nrf_ble_escs_adv_tx_pwr_t tx_pwr)
  {
      slot_boundary_check(&slot_no);
  
      m_reg.slots[slot_no].adv_custom_tx_power = true;
      m_reg.slots[slot_no].custom_tx_power     = tx_pwr;
      set_ranging_data_for_slot(slot_no, tx_pwr);
  }
  
  
  void es_slot_on_write(uint8_t slot_no, uint8_t length, uint8_t * p_frame_data)
  {
      slot_boundary_check(&slot_no);
      
      if(p_frame_data == NULL)
      {
          APP_ERROR_CHECK(NRF_ERROR_NULL);
      }
  
      // If slot is being cleared
      if (length == 0 || (length == 1 && p_frame_data[0] == 0))
      {
          (void)es_slot_reg_clear_slot(&m_reg, slot_no);
      }
  
      // EID slot being configured
      else if (p_frame_data[0] == ES_FRAME_TYPE_EID && \
               (length == ESCS_EID_WRITE_ECDH_LENGTH || length == ESCS_EID_WRITE_IDK_LENGTH))
      {
          configure_eid_slot(slot_no, length, p_frame_data);
      }
  
      // Non-EID slot configured.
      else
      {
          configure_slot(slot_no, length, p_frame_data);
      }
  }
  
  
  void es_slot_encrypted_eid_id_key_set(uint8_t slot_no, nrf_ble_escs_eid_id_key_t * p_eid_id_key)
  {
      slot_boundary_check(&slot_no);
      if (p_eid_id_key != NULL)
      {
          memcpy(&(m_reg.slots[slot_no].encrypted_eid_id_key), p_eid_id_key,
                 sizeof(nrf_ble_escs_eid_id_key_t));
      }
  }
  
  
  void es_slot_eid_ready(uint8_t slot_no)
  {
      m_reg.slots[slot_no].adv_frame.type   = ES_FRAME_TYPE_EID;
      m_reg.slots[slot_no].adv_frame.length = ES_EID_LENGTH;
      es_security_eid_get(slot_no, (uint8_t *)m_reg.slots[slot_no].adv_frame.frame.eid.eid);
      m_reg.slots[slot_no].adv_frame.frame.eid.frame_type = ES_FRAME_TYPE_EID;
      set_ranging_data_for_slot(slot_no, m_reg.slots[slot_no].radio_tx_pwr);
  
      if (m_eid_loaded_from_flash)
      {
          es_slot_reg_update_slot_list_info_on_add(&m_reg, slot_no, ES_FRAME_TYPE_EID, true);
          m_eid_loaded_from_flash = false;
      }
  
      else
      {
          es_slot_reg_update_slot_list_info_on_add(&m_reg, slot_no, ES_FRAME_TYPE_EID, false);
      }
  }
  
  
  static bool slot_is_eid(uint8_t eid_slot_no)
  {
      for (uint8_t i = 0; i < m_reg.num_configured_eid_slots; ++i)
      {
          if (m_reg.eid_slots_configured[i] == eid_slot_no)
          {
              return true;
          }
      }
      
      return false;
  }
  
  
  void es_slot_tlm_update(void)
  {
      if(m_reg.tlm_configured)
      {
          es_tlm_tlm_get(&m_reg.slots[m_reg.tlm_slot].adv_frame.frame.tlm);
      }
  }
  
  
  void es_slot_etlm_update(uint8_t eid_slot_no)
  {
      es_tlm_frame_t  tlm;
      es_etlm_frame_t etlm;
  
      // Ignore the request if eTLM is not required or slot no does not correspond to an EID slot.
      if (!es_slot_reg_etlm_required(&m_reg) || !slot_is_eid(eid_slot_no))
      {
          return;
      }
  
      es_tlm_tlm_get(&tlm);
  
      es_security_tlm_to_etlm(eid_slot_no, &tlm, &etlm);
  
      memcpy(&m_reg.slots[m_reg.tlm_slot].adv_frame.frame.etlm, &etlm, sizeof(es_etlm_frame_t));
      m_reg.slots[m_reg.tlm_slot].adv_frame.length = sizeof(es_etlm_frame_t);
  }
  
  
  const es_slot_reg_t * es_slot_get_registry(void)
  {
      return (const es_slot_reg_t *)&m_reg;
  }
  
  
  
  void es_slots_init(const es_slot_t * p_default_slot)
  {
      ret_code_t       err_code;
      es_flash_flags_t flash_flags = {{0}};
  
      es_slot_reg_init(&m_reg);
      
      m_eid_loaded_from_flash = false;
      
      // Read the flash flags to see if there are any previously stored slot configs
      err_code = es_flash_access_flags(&flash_flags, ES_FLASH_ACCESS_READ);
  
      if (err_code == FDS_ERR_NOT_FOUND)
      {
          // Factory reset or initial boot, load default data
          memcpy(&m_reg.slots[0], p_default_slot, sizeof(*p_default_slot));
          es_slot_reg_update_slot_list_info_on_add(&m_reg, 0, p_default_slot->adv_frame.type, true);
      }
  
      else
      {
          APP_ERROR_CHECK(err_code);
  
          for (uint8_t i = 0; i < APP_MAX_ADV_SLOTS; i++)
          {
              if (!flash_flags.slot_is_empty[i])
              {
                  load_slot_from_flash(i);
              }
          }
      }
  }
  