network_time_protocol.h

#pragma once
 
/************************************************************************************************
 * @file   network_time_protocol.h
 *
 * @brief  Header file defining the Network time protocol helpers
 *
 * @date   2025-01-04
 * @author Aryan Kashem
 ************************************************************************************************/
 
/* Standard library Headers */
#include <cstdint>
#include <ctime>
 
/* Inter-component Headers */
 
/* Intra-component Headers */
 
#define NTP_VERSION 4U
 
#define NTP_LEAP_INDICATOR_OFFSET 6U
 
#define NTP_VERSION_OFFSET 3U
 
#define NTP_MODE_OFFSET 0U
 
#define NTP_POLL_TO_SECONDS(poll) (1U << poll)
 
static constexpr uint32_t NTP_UNIX_EPOCH_DIFF = 2208988800UL;
 
struct NTPTime {
  uint32_t seconds;  
  uint32_t fraction; 
};
 
struct NTPPacket {
  uint8_t flags;           
  uint8_t stratum;         
  uint8_t poll;            
  uint8_t precision;       
  uint32_t rootDelay;      
  uint32_t rootDispersion; 
  uint8_t referenceId[4];  
  NTPTime referenceTime;   
  NTPTime originTime;      
  NTPTime receiveTime;     
  NTPTime transmitTime;    
};
 
enum NTPMode {
  NTP_RESERVED_MODE,  
  NTP_ACTIVE_MODE,    
  NTP_PASSIVE_MODE,   
  NTP_CLIENT_MODE,    
  NTP_SERVER_MODE,    
  NTP_BROADCAST_MODE, 
  NTP_CONTROL_MODE,   
  NUM_NTP_MODES       
};
 
enum NTPLeapIndicator {
  NTP_LI_NONE,                        
  NTP_LI_LAST_MINUTE_OF_THE_DAY_61_S, 
  NTP_LI_LAST_MINUTE_OF_THE_DAY_59_S, 
  NTP_LI_NOSYNC                       
};
 
time_t ntpToUnixTime(NTPTime ntpTime);
 
uint32_t unixToNTPTime(time_t unixTime);
 
void convertNTPTimestamp(NTPTime &timestamp);
 
void dumpNTPPacketData(const NTPPacket packet);