NtpPacket.h

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#pragma once
 
#include <QtCore/QtGlobal>
 
#include <NDEVR/NtpTimestamp.h>
namespace NDEVR
{
    /**
     * NtpPacket flags (first byte of the packet).
     */
    struct NtpPacketFlags {
        /** Mode. */
        unsigned char mode : 3;
 
        /** Version number of the protocol (3 or 4). */
        unsigned char versionNumber : 3;
 
        /** Warns of an impending leap second to be inserted/deleted in the last minute
         * of the current day. */
        unsigned char leapIndicator : 2;
    };
    static_assert(sizeof(NtpPacketFlags) == 1);
 
#pragma pack(push, 1)
    /**
     * Mandatory part of an NTP packet
     */
    struct NtpPacket {
        /** Flags. */
        NtpPacketFlags flags;
 
        /** Stratum of the clock. */
        quint8 stratum;
 
        /** Maximum interval between successive messages, in log2 seconds. Note that the value is signed. */
        qint8 poll;
 
        /** Precision of the clock, in log2 seconds. Note that the value is signed. */
        qint8 precision;
 
        /** Round trip time to the primary reference source, in NTP short format. */
        qint32 rootDelay;
 
        /** Nominal error relative to the primary reference source. */
        qint32 rootDispersion;
 
        /** Reference identifier (either a 4 character string or an IP address). */
        qint8 referenceID[4];
 
        /** The time at which the clock was last set or corrected. */
        NtpTimestamp referenceTimestamp;
 
        /** The time at which the request departed the client for the server. */
        NtpTimestamp originateTimestamp;
 
        /** The time at which the request arrived at the server. */
        NtpTimestamp receiveTimestamp;
 
        /** The time at which the reply departed the server for client. */
        NtpTimestamp transmitTimestamp;
    };
    static_assert(sizeof(NtpPacket) == 48);
 
    /**
     * Optional part of an NTP packet.
     */
    struct NtpAuthenticationInfo {
        /** Key identifier. */
        quint32 keyId;
 
        /** Message Digest. */
        quint8 messageDigest[16];
    };
    static_assert(sizeof(NtpAuthenticationInfo) == 20);
 
    /**
     * Full NTP packet.
     */
    struct NtpFullPacket {
        NtpPacket basic;
        NtpAuthenticationInfo auth;
    };
    static_assert(sizeof(NtpFullPacket) == 68);
 
#pragma pack(pop)
}