NTPClient.h

/* NTPClient.h */
/* Copyright (C) 2012 mbed.org, MIT License
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
 * and associated documentation files (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge, publish, distribute,
 * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies or
 * substantial portions of the Software.
 *
 * 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 AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/** \file
 NTP Client header file
 */

#ifndef NTPCLIENT_H_
#define NTPCLIENT_H_

#include <cstdint>
using std::uint8_t;
using std::uint16_t;
using std::uint32_t;

#include "mbed.h"
#include "UDPSocket.h"

//#include "EthernetInterface.h"

#define NTP_DEFAULT_PORT 123
#define NTP_DEFAULT_TIMEOUT 4000

///NTP client results
enum NTPResult {
	NTP_DNS, ///<Could not resolve name
	NTP_PRTCL, ///<Protocol error
	NTP_TIMEOUT, ///<Connection timeout
	NTP_CONN, ///<Connection error
	NTP_OK = 0, ///<Success
};

/** NTP Client to update the mbed's RTC using a remote time server
 *
 */
class NTPClient {
public:
	/**
	 Instantiate the NTP client
	 */

	NTPClient(NetworkInterface *_stack);

	void keepTime();


	/**Get current time (blocking)
	 Update the time using the server host
	 Blocks until completion
	 @param host NTP server IPv4 address or hostname (will be resolved via DNS)
	 @param port port to use; defaults to 123
	 @param timeout waiting timeout in ms (osWaitForever for blocking function, not recommended)
	 @return 0 on success, NTP error code (<0) on failure
	 */
	NTPResult setTime(const char* host, uint16_t port = NTP_DEFAULT_PORT,
			uint32_t timeout = NTP_DEFAULT_TIMEOUT); //Blocking
	
	/**Start NTP thread and maintain time
	 @param host NTP server IPv4 address or hostname (will be resolved via DNS)
	 @param port port to use; defaults to 123
	 @param timeout waiting timeout in ms (osWaitForever for blocking function, not recommended)
	 @return 0 on success, NTP error code (<0) on failure
	 */
	NTPResult start(const char* _host,uint16_t seconds = 900, uint16_t _port = NTP_DEFAULT_PORT); 
	
	/**Start NTP thread and maintain time
	 @return 0 on success, NTP error code (<0) on failure
	 */
	NTPResult stop();
	

private:
	struct NTPPacket //See RFC 4330 for Simple NTP
	{
		//WARN: We are in LE! Network is BE!
		//LSb first
		unsigned mode :3;
		unsigned vn :3;
		unsigned li :2;

		uint8_t stratum;
		uint8_t poll;
		uint8_t precision;
		//32 bits header

		uint32_t rootDelay;
		uint32_t rootDispersion;
		uint32_t refId;

		uint32_t refTm_s;
		uint32_t refTm_f;
		uint32_t origTm_s;
		uint32_t origTm_f;
		uint32_t rxTm_s;
		uint32_t rxTm_f;
		uint32_t txTm_s;
		uint32_t txTm_f;
	}__attribute__ ((packed));

	UDPSocket m_sock;
	NetworkInterface *stack;
	Thread NTPThread;
	char host[50];
	uint16_t port;
	int delay;//in seconds
};

#endif /* NTPCLIENT_H_ */