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 <cstdint>
00028 
00029 using std::uint8_t;
00030 using std::uint16_t;
00031 using std::uint32_t;
00032 
00033 #include "UDPSocket.h"
00034 
00035 #define NTP_DEFAULT_PORT 123
00036 #define NTP_DEFAULT_TIMEOUT 4000
00037 
00038 ///NTP client results
00039 enum NTPResult
00040 {
00041   NTP_DNS, ///<Could not resolve name
00042   NTP_PRTCL, ///<Protocol error
00043   NTP_TIMEOUT, ///<Connection timeout
00044   NTP_CONN, ///<Connection error
00045   NTP_OK = 0, ///<Success
00046 };
00047 
00048 /** NTP Client to update the mbed's RTC using a remote time server
00049 *
00050 */
00051 class NTPClient
00052 {
00053 public:
00054   /**
00055   Instantiate the NTP client
00056   */
00057   NTPClient();
00058 
00059   /**Get current time (blocking)
00060   Update the time using the server host
00061   Blocks until completion
00062   @param host NTP server IPv4 address or hostname (will be resolved via DNS)
00063   @param port port to use; defaults to 123
00064   @param timeout waiting timeout in ms (osWaitForever for blocking function, not recommended)
00065   @return 0 on success, NTP error code (<0) on failure
00066   */
00067   NTPResult setTime(const char* host, uint16_t port = NTP_DEFAULT_PORT, uint32_t timeout = NTP_DEFAULT_TIMEOUT); //Blocking
00068 
00069 private:
00070   struct NTPPacket //See RFC 4330 for Simple NTP
00071   {
00072     //WARN: We are in LE! Network is BE!
00073     //LSb first
00074     unsigned mode : 3;
00075     unsigned vn : 3;
00076     unsigned li : 2;
00077 
00078     uint8_t stratum;
00079     uint8_t poll;
00080     uint8_t precision;
00081     //32 bits header
00082 
00083     uint32_t rootDelay;
00084     uint32_t rootDispersion;
00085     uint32_t refId;
00086 
00087     uint32_t refTm_s;
00088     uint32_t refTm_f;
00089     uint32_t origTm_s;
00090     uint32_t origTm_f;
00091     uint32_t rxTm_s;
00092     uint32_t rxTm_f;
00093     uint32_t txTm_s;
00094     uint32_t txTm_f;
00095   } __attribute__ ((packed));
00096   
00097   UDPSocket m_sock;
00098 
00099 };
00100 
00101 
00102 #endif /* NTPCLIENT_H_ */