i2pd/Timestamp.cpp
2016-09-21 16:18:51 -04:00

51 lines
1.3 KiB
C++

#include <inttypes.h>
#include <string.h>
#include <boost/asio.hpp>
#include "I2PEndian.h"
#include "Timestamp.h"
namespace i2p
{
namespace util
{
std::chrono::system_clock::duration g_TimeOffset = std::chrono::system_clock::duration::zero ();
void SyncTimeWithNTP (const std::string& address)
{
boost::asio::io_service service;
boost::asio::ip::udp::resolver::query query (boost::asio::ip::udp::v4 (), address, "ntp");
boost::system::error_code ec;
auto it = boost::asio::ip::udp::resolver (service).resolve (query, ec);
if (!ec && it != boost::asio::ip::udp::resolver::iterator())
{
auto ep = (*it).endpoint (); // take first one
boost::asio::ip::udp::socket socket (service);
socket.open (boost::asio::ip::udp::v4 (), ec);
if (!ec)
{
uint8_t request[48];// 48 bytes NTP request
memset (request, 0, 48);
request[0] = 0x80; // client mode, version 0
uint8_t * response = new uint8_t[1500]; // MTU
size_t len = 0;
try
{
socket.send_to (boost::asio::buffer (request, 48), ep);
len = socket.receive_from (boost::asio::buffer (response, 1500), ep);
}
catch (std::exception& e)
{
}
if (len >= 8)
{
uint32_t ts = bufbe32toh (response + 4);
if (ts > 2208988800U) ts -= 2208988800U; // 1/1/1970 from 1/1/1900
}
delete[] response;
}
}
}
}
}