Tasmota/lib/ArduinoNTPd/NTPServer.cpp

79 lines
2.7 KiB
C++

/*
* File: NTPServer.cpp
* Description:
* NTP server implementation.
* Author: Mooneer Salem <mooneer@gmail.com>
* License: New BSD License
*/
#include <WiFiUdp.h>
#include "NTPPacket.h"
#include "NTPServer.h"
#define NTP_PORT 123
#define NTP_TIMESTAMP_DIFF (2208988800) // 1900 to 1970 in seconds
bool NtpServer::beginListening()
{
if (timeServerPort_.begin(NTP_PORT)){
return true;
}
return false;
}
bool NtpServer::processOneRequest(uint32_t utc, uint32_t millisecs)
{
// We need the time we've received the packet in our response.
uint32_t recvSecs = utc + NTP_TIMESTAMP_DIFF;
double recvFractDouble = (double)millisecs/0.00023283064365386963; // millisec/((10^6)/(2^32))
uint32_t recvFract = (double)recvFractDouble; //TODO: really handle this!!!
bool processed = false;
int packetDataSize = timeServerPort_.parsePacket();
if (packetDataSize && packetDataSize >= NtpPacket::PACKET_SIZE)
{
// Received what is probably an NTP packet. Read it in and verify
// that it's legit.
NtpPacket packet;
timeServerPort_.read((char*)&packet, NtpPacket::PACKET_SIZE);
// TODO: verify packet.
// Populate response.
packet.swapEndian();
packet.leapIndicator(0);
packet.versionNumber(4);
packet.mode(4);
packet.stratum = 2; // I guess stratum 1 is too optimistic
packet.poll = 10; // 6-10 per RFC 5905.
packet.precision = -21; // ~0.5 microsecond precision.
packet.rootDelay = 0; //60 * (0xFFFF / 1000); // ~60 milliseconds, TBD
packet.rootDispersion = 0; //10 * (0xFFFF / 1000); // ~10 millisecond dispersion, TBD
packet.referenceId[0] = 'G';
packet.referenceId[1] = 'P';
packet.referenceId[2] = 'S';
packet.referenceId[3] = 0;
packet.referenceTimestampSeconds = utc;
packet.referenceTimestampFraction = recvFract;
packet.originTimestampSeconds = packet.transmitTimestampSeconds;
packet.originTimestampFraction = packet.transmitTimestampFraction;
packet.receiveTimestampSeconds = recvSecs;
packet.receiveTimestampFraction = recvFract;
// ...and the transmit time.
// timeSource_.now(&packet.transmitTimestampSeconds, &packet.transmitTimestampFraction);
// Now transmit the response to the client.
packet.swapEndian();
timeServerPort_.beginPacket(timeServerPort_.remoteIP(), timeServerPort_.remotePort());
for (int count = 0; count < NtpPacket::PACKET_SIZE; count++)
{
timeServerPort_.write(packet.packet()[count]);
}
timeServerPort_.endPacket();
processed = true;
}
return processed;
}