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 "NetworkStack.h"
00028 #include "UDPSocket.h"
00029 
00030 #define NTP_DEFAULT_PORT 123
00031 #define NTP_DEFAULT_TIMEOUT 1000
00032 
00033 ///NTP client results
00034 enum NTPResult
00035 {
00036     NTP_DNS, ///<Could not resolve name
00037     NTP_PRTCL, ///<Protocol error
00038     NTP_TIMEOUT, ///<Connection timeout
00039     NTP_CONN, ///<Connection error
00040     NTP_OK = 0, ///<Success
00041 };
00042 
00043 /** NTP Client to update the mbed's RTC using a remote time server
00044 *
00045 */
00046 class NTPClient
00047 {
00048 public:
00049     /**
00050     Instantiate the NTP client
00051     */
00052     NTPClient(NetworkInterface *networkInterface);
00053 
00054     /**Get current time (blocking)
00055     Update the time using the server host
00056     Blocks until completion
00057     @param host NTP server IPv4 address or hostname (will be resolved via DNS)
00058     @param port port to use; defaults to 123
00059     @param timeout waiting timeout in ms (osWaitForever for blocking function, not recommended)
00060     @return 0 on success, NTP error code (<0) on failure
00061     */
00062     NTPResult setTime(const char* host, uint16_t port = NTP_DEFAULT_PORT, uint32_t timeout = NTP_DEFAULT_TIMEOUT); //Blocking
00063 
00064 private:
00065     struct NTPPacket //See RFC 4330 for Simple NTP
00066     {
00067         //WARN: We are in LE! Network is BE!
00068         //LSb first
00069         unsigned mode : 3;
00070         unsigned vn : 3;
00071         unsigned li : 2;
00072 
00073         uint8_t stratum;
00074         uint8_t poll;
00075         uint8_t precision;
00076         //32 bits header
00077 
00078         uint32_t rootDelay;
00079         uint32_t rootDispersion;
00080         uint32_t refId;
00081 
00082         uint32_t refTm_s;
00083         uint32_t refTm_f;
00084         uint32_t origTm_s;
00085         uint32_t origTm_f;
00086         uint32_t rxTm_s;
00087         uint32_t rxTm_f;
00088         uint32_t txTm_s;
00089         uint32_t txTm_f;
00090     } __attribute__ ((packed));
00091   
00092     UDPSocket m_sock;
00093     NetworkInterface *m_net;
00094 };
00095 
00096 
00097 #endif /* NTPCLIENT_H_ */