NTPClient.h

00001 /* NTPClient.h */
00002 /* Copyright (C) 2012 mbed.org, MIT License
00003  *
00004  * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
00005  * and associated documentation files (the "Software"), to deal in the Software without restriction,
00006  * including without limitation the rights to use, copy, modify, merge, publish, distribute,
00007  * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
00008  * furnished to do so, subject to the following conditions:
00009  *
00010  * The above copyright notice and this permission notice shall be included in all copies or
00011  * substantial portions of the Software.
00012  *
00013  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
00014  * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
00015  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
00016  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00017  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00018  */
00019 
00020 /** \file
00021  * NTP Client header file
00022  */
00023 
00024 #ifndef NTPCLIENT_H_
00025 #define NTPCLIENT_H_
00026 
00027 #include <stdint.h>
00028 #include "UDPSocket.h"
00029 #include "NetworkInterface.h"
00030 
00031 #define NTP_DEFAULT_PORT    123
00032 #define NTP_DEFAULT_TIMEOUT 4000
00033 
00034 ///NTP client results
00035 enum NTPResult
00036 {
00037   NTP_DNS,      ///<Could not resolve name
00038   NTP_PRTCL,    ///<Protocol error
00039   NTP_TIMEOUT,  ///<Connection timeout
00040   NTP_CONN,     ///<Connection error
00041   NTP_OK = 0,   ///<Success
00042 };
00043 
00044 /** NTP Client to update the mbed's RTC using a remote time server
00045 *
00046 */
00047 class NTPClient
00048 {
00049 public:
00050     /**
00051     * Instantiate the NTP client
00052     */
00053     NTPClient(NetworkInterface & _m_intf);
00054 
00055     /**Get current time (blocking)
00056     Update the time using the server host
00057     Blocks until completion
00058     @param host NTP server IPv4 address or hostname (will be resolved via DNS)
00059     @param port port to use; defaults to 123
00060     @param timeout waiting timeout in ms (osWaitForever for blocking function, not recommended)
00061     @return 0 on success, NTP error code (<0) on failure
00062     */
00063     NTPResult setTime(const char* host, uint16_t port = NTP_DEFAULT_PORT, uint32_t timeout = NTP_DEFAULT_TIMEOUT);
00064 
00065 private:
00066     struct NTPPacket //See RFC 4330 for Simple NTP
00067     {
00068         //WARN: We are in Little Endian! Network is Big Endian!
00069         //LSb first
00070         unsigned mode : 3;
00071         unsigned vn : 3;
00072         unsigned li : 2;
00073 
00074         uint8_t stratum;
00075         uint8_t poll;
00076         uint8_t precision;
00077         //32 bits header
00078 
00079         uint32_t rootDelay;
00080         uint32_t rootDispersion;
00081         uint32_t refId;
00082 
00083         uint32_t refTm_s;
00084         uint32_t refTm_f;
00085         uint32_t origTm_s;
00086         uint32_t origTm_f;
00087         uint32_t rxTm_s;
00088         uint32_t rxTm_f;
00089         uint32_t txTm_s;
00090         uint32_t txTm_f;
00091     } __attribute__ ((packed));
00092 
00093     NetworkInterface & m_intf;
00094     UDPSocket m_sock;
00095 };
00096 
00097 #endif /* NTPCLIENT_H_ */