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 #ifndef NTP_CLIENT_H
00025 #define NTP_CLIENT_H
00026 
00027 #include "if/net/net.h"
00028 #include "api/UDPSocket.h"
00029 #include "api/DNSRequest.h"
00030 #include "mbed.h"
00031 
00032 enum NTPResult
00033 {
00034   NTP_OK,
00035   NTP_PROCESSING,
00036   NTP_PRTCL, //Protocol error
00037   NTP_TIMEOUT, //Connection timeout
00038   NTP_DNS //Could not resolve DNS Addr
00039 };
00040 
00041 class NTPClient : protected NetService
00042 {
00043 public:
00044   NTPClient();
00045   virtual ~NTPClient();
00046   
00047   //High level setup functions
00048   NTPResult setTime(const Host& host); //Blocking
00049   NTPResult setTime(const Host& host, void (*pMethod)(NTPResult)); //Non blocking
00050   template<class T> 
00051   NTPResult setTime(const Host& host, T* pItem, void (T::*pMethod)(NTPResult)) //Non blocking
00052   {
00053     setOnResult(pItem, pMethod);
00054     doSetTime(host);
00055     return NTP_PROCESSING;
00056   }
00057   
00058   void doSetTime(const Host& host);
00059   
00060   void setOnResult( void (*pMethod)(NTPResult) );
00061   class CDummy;
00062   template<class T> 
00063   void setOnResult( T* pItem, void (T::*pMethod)(NTPResult) )
00064   {
00065     m_pCbItem = (CDummy*) pItem;
00066     m_pCbMeth = (void (CDummy::*)(NTPResult)) pMethod;
00067   }
00068   
00069   void close();
00070   
00071 protected:
00072   virtual void poll(); //Called by NetServices
00073   
00074 private:
00075   void init();
00076   void open();
00077   
00078   __packed struct NTPPacket //See RFC 4330 for Simple NTP
00079   {
00080     //WARN: We are in LE! Network is BE!
00081     //LSb first
00082     unsigned mode : 3;
00083     unsigned vn : 3;
00084     unsigned li : 2;
00085     
00086     uint8_t stratum;
00087     uint8_t poll;
00088     uint8_t precision;
00089     //32 bits header
00090     
00091     uint32_t rootDelay;
00092     uint32_t rootDispersion;
00093     uint32_t refId;
00094     
00095     uint32_t refTm_s;
00096     uint32_t refTm_f;
00097     uint32_t origTm_s;
00098     uint32_t origTm_f;
00099     uint32_t rxTm_s;
00100     uint32_t rxTm_f;
00101     uint32_t txTm_s;
00102     uint32_t txTm_f;
00103   };
00104 
00105   void process(); //Main state-machine
00106 
00107   void setTimeout(int ms);
00108   void resetTimeout();
00109   
00110   void onTimeout(); //Connection has timed out
00111   void onDNSReply(DNSReply r);
00112   void onUDPSocketEvent(UDPSocketEvent e);
00113   void onResult(NTPResult r); //Called when exchange completed or on failure
00114   
00115   NTPResult blockingProcess(); //Called in blocking mode, calls Net::poll() until return code is available
00116 
00117   UDPSocket* m_pUDPSocket;
00118 
00119   enum NTPStep
00120   {
00121     NTP_PING,
00122     NTP_PONG
00123   };
00124   
00125   NTPStep m_state;
00126   
00127   NTPPacket m_pkt;
00128   
00129   CDummy* m_pCbItem;
00130   void (CDummy::*m_pCbMeth)(NTPResult);
00131   
00132   void (*m_pCb)(NTPResult);
00133   
00134   Timer m_watchdog;
00135   int m_timeout;
00136   
00137   bool m_closed;
00138   
00139   Host m_host;
00140   
00141   DNSRequest* m_pDnsReq;
00142   
00143   NTPResult m_blockingResult; //Result if blocking mode
00144 
00145 };
00146 
00147 #endif