* NTP client implementation

Net/src/NTPClient.cpp

@@ -0,0 +1,109 @@
+//
+// 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