poco/Net/src/NTPClient.cpp

//
// NTPClient.cpp
//
// $Id: //poco/1.4/Net/src/NTPClient.cpp#1 $
//
// Library: Net
// Package: NTP
// Module:  NTPClient
//
// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
// 
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//


#include "Poco/Net/SocketAddress.h"
#include "Poco/Net/NTPClient.h"
#include "Poco/Net/NTPPacket.h"
#include "Poco/Net/DatagramSocket.h"
#include "Poco/Net/NetException.h"


using Poco::TimeoutException;


namespace Poco {
namespace Net {


NTPClient::NTPClient(IPAddress::Family family, int timeout): 
	_family(family), _timeout(timeout)
{
}


NTPClient::~NTPClient()
{
}


int NTPClient::request(const std::string& address) const
{
	SocketAddress addr(address, 123);
	return request(addr);
}


int NTPClient::request(SocketAddress& address) const
{
	Poco::Net::SocketAddress sa;
	DatagramSocket ntpSocket(_family);
	ntpSocket.setReceiveTimeout(_timeout);
	ntpSocket.bind(sa);

	SocketAddress returnAddress;

	NTPEventArgs eventArgs(address);

	NTPPacket packet;
	Poco::UInt8 p[1024];
	packet.packet(&p[0]);

	ntpSocket.sendTo(p, 48, address);

	int received = 0;
	try
	{
		Poco::Net::SocketAddress sender;
		int n = ntpSocket.receiveFrom(p, sizeof(p)-1, sender);

		if (n < 48) // NTP packet must have at least 48 bytes
			throw Poco::Net::NTPException("Invalid response received");

		packet.setPacket(p);
		eventArgs.setPacket(packet);
		++received;
		response.notify(this, eventArgs);
	}
	catch (Poco::TimeoutException &)
	{
		// ignore
	}

	return received;
}


} } // namespace Poco::Net