text: /**
   * Copyright (c) 2016 - 2020, Nordic Semiconductor ASA
   *
   * 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, except as embedded into a Nordic
   *    Semiconductor ASA integrated circuit in a product or a software update for
   *    such product, 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 Nordic Semiconductor ASA nor the names of its
   *    contributors may be used to endorse or promote products derived from this
   *    software without specific prior written permission.
   *
   * 4. This software, with or without modification, must only be used with a
   *    Nordic Semiconductor ASA integrated circuit.
   *
   * 5. Any software provided in binary form under this license must not be reverse
   *    engineered, decompiled, modified and/or disassembled.
   *
   * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
   * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA 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.
   *
   */
  #include <stdint.h>
  #include <string.h>
  #include "es_slot.h"
  #include "es_flash.h"
  #include "es_security.h"
  #include "es_slot_reg.h"
  #include "es_tlm.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 (uint32_t i = 0; i < ESCS_NUM_OF_SUPPORTED_TX_POWER; ++i)
          {
              if (supported_tx[i] >= tx_power)
              {
                  ranging_data = ranging_data_array[i];
                  break;
              }
          }
      }
      es_adv_frame_t * frame = &m_reg.slots[slot_no].adv_frame;
      switch (frame->type)
      {
          case ES_FRAME_TYPE_UID:
          {
              es_uid_frame_t * uid = &frame->frame.uid;
              uid->ranging_data    = ranging_data;
              break;
          }
  
          case ES_FRAME_TYPE_URL:
          {
              es_url_frame_t * url = &frame->frame.url;
              url->ranging_data    = ranging_data;
              break;
          }
  
          case ES_FRAME_TYPE_EID:
          {
              es_eid_frame_t * eid = &frame->frame.eid;
              eid->ranging_data    = ranging_data;
              break;
          }
  
          case ES_FRAME_TYPE_TLM:
              APP_ERROR_CHECK(NRF_ERROR_INVALID_PARAM);
              break;
      }
  }
  
  
  /**@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 const * 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 - 1);
              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 const * p_frame_data)
  {
      // 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.
      (void)es_slot_reg_clear_slot(&m_reg, 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)
      {
          es_security_client_pub_ecdh_receive(slot_no,
                                              (uint8_t*)&p_frame_data[ESCS_EID_WRITE_PUB_KEY_INDEX],
                                              p_frame_data[ESCS_EID_WRITE_ECDH_LENGTH -1]);
      }
  
      else if (length == ESCS_EID_WRITE_IDK_LENGTH)
      {
          es_security_shared_ik_receive(slot_no,
                                        (uint8_t*)&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_plain_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 const * p_frame_data)
  {
      slot_boundary_check(&slot_no);
  
      if (p_frame_data == NULL)
      {
          APP_ERROR_CHECK(NRF_ERROR_NULL);
      }
  
      // 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))
      {
          if (m_reg.slots[slot_no].configured)
              (void)es_slot_reg_clear_slot(&m_reg, slot_no);
          configure_eid_slot(slot_no, length, p_frame_data);
      }
      // Non-EID slot configured.
      else
      {
          if (m_reg.slots[slot_no].configured)
              (void)es_slot_reg_clear_slot(&m_reg, slot_no);
          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 (uint32_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 (uint32_t i = 0; i < APP_MAX_ADV_SLOTS; ++i)
          {
              if (!flash_flags.slot_is_empty[i])
              {
                  load_slot_from_flash(i);
              }
          }
      }
  }
  