File content as of revision 0:9282d46b9f92:

/* 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 <stdint.h>
#include "UDPSocket.h"
#include "NetworkInterface.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 & _m_intf);

    /**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);

private:
    struct NTPPacket //See RFC 4330 for Simple NTP
    {
        //WARN: We are in Little Endian! Network is Big Endian!
        //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));

    NetworkInterface & m_intf;
    UDPSocket m_sock;
};

#endif /* NTPCLIENT_H_ */