NTPClient.cpp

00001 /* NTPClient.cpp */
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 //Debug is disabled by default
00021 #if 0
00022 //Enable debug
00023 #define __DEBUG__
00024 #include <cstdio>
00025 #define DBG(x, ...) std::printf("[NTPClient : DBG]"x"\r\n", ##__VA_ARGS__); 
00026 #define WARN(x, ...) std::printf("[NTPClient : WARN]"x"\r\n", ##__VA_ARGS__); 
00027 #define ERR(x, ...) std::printf("[NTPClient : ERR]"x"\r\n", ##__VA_ARGS__); 
00028 
00029 #else
00030 //Disable debug
00031 #define DBG(x, ...) 
00032 #define WARN(x, ...)
00033 #define ERR(x, ...) 
00034 
00035 #endif
00036 #include "NetworkInterface.h"
00037 #include "NTPClient.h"
00038 
00039 #include "UDPSocket.h"
00040 
00041 #include "mbed.h" //time() and set_time()
00042 
00043 #define NTP_PORT 123
00044 #define NTP_CLIENT_PORT 0 //Random port
00045 #define NTP_TIMESTAMP_DELTA 2208988800ull //Diff btw a UNIX timestamp (Starting Jan, 1st 1970) and a NTP timestamp (Starting Jan, 1st 1900)
00046 
00047 /*NTPClient::NTPClient() : m_sock()
00048 {
00049 
00050 }*/
00051 
00052 NTPClient::NTPClient(NetworkInterface * _m_intf, int utcOffset) 
00053     : m_intf(_m_intf),
00054     utc_offset(utcOffset)
00055 {
00056 }
00057 
00058 #ifdef htons
00059 #undef htons
00060 #endif /* htons */
00061 #ifdef htonl
00062 #undef htonl
00063 #endif /* htonl */
00064 #ifdef ntohs
00065 #undef ntohs
00066 #endif /* ntohs */
00067 #ifdef ntohl
00068 #undef ntohl
00069 #endif /* ntohl */
00070 
00071 
00072 #if ((__BYTE_ORDER__) == (__ORDER_LITTLE_ENDIAN__))
00073 
00074 #define htons(x) ((((x) & 0xff) << 8) | (((x) & 0xff00) >> 8))
00075 #define ntohs(x) htons(x)
00076 #define htonl(x) ((((x) & 0xff) << 24) | \
00077                      (((x) & 0xff00) << 8) | \
00078                      (((x) & 0xff0000UL) >> 8) | \
00079                      (((x) & 0xff000000UL) >> 24))
00080 #define ntohl(x) htonl(x)
00081 
00082 #else
00083 
00084 #define htons(x)  (x)
00085 #define htonl(x)  (x)
00086 #define ntohl(x)  (x)
00087 #define ntohs(x)  (x)
00088 
00089 #endif 
00090 
00091 
00092 NTPResult NTPClient::setTime(const char* host, uint16_t port, uint32_t timeout)
00093 {
00094 #ifdef __DEBUG__
00095   time_t ctTime;
00096   ctTime = time(NULL);
00097   set_time(ctTime);
00098   DBG("Time is set to (UTC): %s", ctime(&ctTime));
00099 #endif
00100 
00101     
00102   SocketAddress address(0, port);
00103   int r = m_intf->gethostbyname(host, &address);  
00104   if (r) {
00105         printf("error: 'gethostbyname(\"%s\")' failed with code %d\r\n", host, r);
00106   } else if (!address) {
00107         printf("error: 'gethostbyname(\"%s\")' returned null IP address\r\n", host);
00108   }  
00109   //printf ("address: %s\n\r",address.get_ip_address());
00110    
00111   //Create & bind socket
00112   if (m_sock.open(m_intf) < 0) printf ("ERROR sock open \n\r");  
00113   m_sock.set_timeout(timeout);  
00114 
00115   struct NTPPacket pkt;  
00116   memset (&pkt, 0, sizeof(NTPPacket));   
00117 
00118   //Now ping the server and wait for response
00119   DBG("Ping");
00120   //Prepare NTP Packet:
00121   pkt.li = 0; //Leap Indicator : No warning
00122   pkt.vn = 4; //Version Number : 4
00123   pkt.mode = 3; //Client mode
00124   pkt.stratum = 0; //Not relevant here
00125   pkt.poll = 0; //Not significant as well
00126   pkt.precision = 0; //Neither this one is
00127 
00128   int ret = m_sock.sendto(address, (char*)&pkt, sizeof(NTPPacket) ); 
00129   if (ret < 0 )
00130   {
00131     ERR("Could not send packet %d", ret);
00132     m_sock.close();
00133     return NTP_CONN;
00134   }
00135 
00136   //Read response
00137   DBG("Pong");
00138 
00139   ret = m_sock.recvfrom(&address, (char*)&pkt, sizeof(NTPPacket) );  // LICIO
00140   if(ret < 0)
00141   {
00142     ERR("Could not receive packet %d", ret);
00143     m_sock.close();
00144     return NTP_CONN;
00145   }
00146 
00147   if(ret < sizeof(NTPPacket)) //TODO: Accept chunks
00148   {
00149     ERR("Receive packet size does not match");
00150     m_sock.close();
00151     return NTP_PRTCL;
00152   }
00153 
00154   if( pkt.stratum == 0)  //Kiss of death message : Not good !
00155   {
00156     ERR("Kissed to death!");
00157     m_sock.close();
00158     return NTP_PRTCL;
00159   }
00160 
00161   //Correct Endianness
00162   pkt.refTm_s = ntohl( pkt.refTm_s ); 
00163   pkt.refTm_f = ntohl( pkt.refTm_f );
00164   pkt.origTm_s = ntohl( pkt.origTm_s );
00165   pkt.origTm_f = ntohl( pkt.origTm_f );
00166   pkt.rxTm_s = ntohl( pkt.rxTm_s );
00167   pkt.rxTm_f = ntohl( pkt.rxTm_f );
00168   pkt.txTm_s = ntohl( pkt.txTm_s );
00169   pkt.txTm_f = ntohl( pkt.txTm_f );
00170 
00171   // see RFC 4330 p.13
00172   int timeoffset = utc_offset * 60 * 60;  
00173   time_t txTm = (time_t)((pkt.txTm_s - NTP_TIMESTAMP_DELTA) + timeoffset);  
00174 
00175   set_time(txTm); 
00176 
00177 #ifdef __DEBUG__
00178   ctTime = time(NULL);
00179   DBG("Time is now (UTC): %s", ctime(&ctTime));
00180 #endif
00181   m_sock.close();
00182 
00183   return NTP_OK;
00184 }
00185