NTPClient.h

00001 
00002 /*
00003 Copyright (c) 2010 Donatien Garnier (donatiengar [at] gmail [dot] com)
00004  
00005 Permission is hereby granted, free of charge, to any person obtaining a copy
00006 of this software and associated documentation files (the "Software"), to deal
00007 in the Software without restriction, including without limitation the rights
00008 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00009 copies of the Software, and to permit persons to whom the Software is
00010 furnished to do so, subject to the following conditions:
00011  
00012 The above copyright notice and this permission notice shall be included in
00013 all copies or substantial portions of the Software.
00014  
00015 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00016 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00017 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00018 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00019 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00020 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00021 THE SOFTWARE.
00022 */
00023 
00024 /** \file
00025 NTP Client header file
00026 */
00027 
00028 #ifndef NTP_CLIENT_H
00029 #define NTP_CLIENT_H
00030 
00031 #include "core/net.h"
00032 #include "core/netservice.h"
00033 #include "api/UDPSocket.h"
00034 #include "mbed.h"
00035 
00036 ///NTP Client results
00037 enum NTPResult
00038 {
00039   NTP_OK, ///<Success
00040   NTP_PROCESSING, ///<Processing
00041   NTP_PRTCL, ///<Protocol error
00042   NTP_TIMEOUT, ///<Connection timeout
00043   NTP_DNS ///<Could not resolve DNS hostname
00044 };
00045 
00046   __packed struct NTPPacket //See RFC 4330 for Simple NTP
00047   {
00048     //WARN: We are in LE! Network is BE!
00049     //LSb first
00050     unsigned mode : 3;
00051     unsigned vn : 3;
00052     unsigned li : 2;
00053     
00054     uint8_t stratum;
00055     uint8_t poll;
00056     uint8_t precision;
00057     //32 bits header
00058     
00059     uint32_t rootDelay;
00060     uint32_t rootDispersion;
00061     uint32_t refId;
00062     
00063     uint32_t refTm_s;
00064     uint32_t refTm_f;
00065     uint32_t origTm_s;
00066     uint32_t origTm_f;
00067     uint32_t rxTm_s;
00068     uint32_t rxTm_f;
00069     uint32_t txTm_s;
00070     uint32_t txTm_f;
00071   };
00072 
00073 /**
00074 The NTP client is a simple UDP client that will update the mbed's RTC
00075 */
00076 class NTPClient
00077 {
00078 public:
00079   /**
00080   Instantiates the NTP client
00081   */
00082   NTPClient();
00083   ~NTPClient();
00084   
00085   /**
00086       Updates the time using the server host, blocks until completion
00087       @param host : NTP server
00088   */
00089   NTPResult setTime(const Host& host); //Blocking
00090  
00091   void close();
00092   
00093 private:
00094   void init();
00095   void open();
00096   
00097   /**
00098       Updates the time using the server host
00099       The function returns immediately and calls the previously set callback on completion or error
00100       @param host : NTP server
00101   */
00102   void doSetTime(const Host& host);
00103 
00104   void process(); //Main state-machine
00105 
00106   void setTimeout(int ms);
00107   void resetTimeout();
00108   
00109   void onTimeout(); //Connection has timed out
00110   void onUDPSocketEvent(UDPSocketEvent e);
00111   void onResult(NTPResult r); //Called when exchange completed or on failure
00112   
00113   NTPResult blockingProcess(); //Called in blocking mode, calls Net::poll() until return code is available
00114 
00115   UDPSocket* _pUDPSocket;
00116   
00117   
00118 
00119   enum NTPStep
00120   {
00121     NTP_PING,
00122     NTP_PONG
00123   };
00124   
00125   NTPStep _state;
00126   
00127   NTPPacket _pkt;
00128   
00129   Timer *_watchdog;
00130   int _timeout;
00131   
00132   bool _closed;
00133   
00134   Host _host;
00135   
00136   NTPResult _blockingResult; //Result if blocking mode
00137 
00138 };
00139 
00140 #endif