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) : m_intf(_m_intf)
00053 {
00054 }
00055 
00056 #ifdef htons
00057 #undef htons
00058 #endif /* htons */
00059 #ifdef htonl
00060 #undef htonl
00061 #endif /* htonl */
00062 #ifdef ntohs
00063 #undef ntohs
00064 #endif /* ntohs */
00065 #ifdef ntohl
00066 #undef ntohl
00067 #endif /* ntohl */
00068 
00069 
00070 #if ((__BYTE_ORDER__) == (__ORDER_LITTLE_ENDIAN__))
00071 
00072 #define htons(x) ((((x) & 0xff) << 8) | (((x) & 0xff00) >> 8))
00073 #define ntohs(x) htons(x)
00074 #define htonl(x) ((((x) & 0xff) << 24) | \
00075                      (((x) & 0xff00) << 8) | \
00076                      (((x) & 0xff0000UL) >> 8) | \
00077                      (((x) & 0xff000000UL) >> 24))
00078 #define ntohl(x) htonl(x)
00079 
00080 #else
00081 
00082 #define htons(x)  (x)
00083 #define htonl(x)  (x)
00084 #define ntohl(x)  (x)
00085 #define ntohs(x)  (x)
00086 
00087 #endif 
00088 
00089 
00090 NTPResult NTPClient::setTime(const char* host, uint16_t port, uint32_t timeout)
00091 {
00092 #ifdef __DEBUG__
00093   time_t ctTime;
00094   ctTime = time(NULL);
00095   set_time(ctTime);
00096   DBG("Time is set to (UTC): %s", ctime(&ctTime));
00097 #endif
00098 
00099   SocketAddress address(0, port);
00100   int r = m_intf.gethostbyname( host, &address);  
00101   if (r) {
00102         printf("error: 'gethostbyname(\"%s\")' failed with code %d\r\n", host, r);
00103   } else if (!address) {
00104         printf("error: 'gethostbyname(\"%s\")' returned null IP address\r\n", host);
00105   }  
00106   //printf ("address: %s\n\r",address.get_ip_address());
00107    
00108   //Create & bind socket
00109   if (m_sock.open(&m_intf) < 0) printf ("ERROR sock open \n\r");  
00110   m_sock.set_timeout(timeout);  
00111 
00112   struct NTPPacket pkt;  
00113   memset (&pkt, 0, sizeof(NTPPacket));   
00114 
00115   //Now ping the server and wait for response
00116   DBG("Ping");
00117   //Prepare NTP Packet:
00118   pkt.li = 0; //Leap Indicator : No warning
00119   pkt.vn = 4; //Version Number : 4
00120   pkt.mode = 3; //Client mode
00121   pkt.stratum = 0; //Not relevant here
00122   pkt.poll = 0; //Not significant as well
00123   pkt.precision = 0; //Neither this one is
00124 
00125   int ret = m_sock.sendto(address, (char*)&pkt, sizeof(NTPPacket) ); 
00126   if (ret < 0 )
00127   {
00128     ERR("Could not send packet %d", ret);
00129     m_sock.close();
00130     return NTP_CONN;
00131   }
00132 
00133   //Read response
00134   DBG("Pong");
00135 
00136   ret = m_sock.recvfrom(&address, (char*)&pkt, sizeof(NTPPacket) );  // LICIO
00137   if(ret < 0)
00138   {
00139     ERR("Could not receive packet %d", ret);
00140     m_sock.close();
00141     return NTP_CONN;
00142   }
00143 
00144   if(ret < sizeof(NTPPacket)) //TODO: Accept chunks
00145   {
00146     ERR("Receive packet size does not match");
00147     m_sock.close();
00148     return NTP_PRTCL;
00149   }
00150 
00151   if( pkt.stratum == 0)  //Kiss of death message : Not good !
00152   {
00153     ERR("Kissed to death!");
00154     m_sock.close();
00155     return NTP_PRTCL;
00156   }
00157 
00158   //Correct Endianness
00159   pkt.refTm_s = ntohl( pkt.refTm_s ); 
00160   pkt.refTm_f = ntohl( pkt.refTm_f );
00161   pkt.origTm_s = ntohl( pkt.origTm_s );
00162   pkt.origTm_f = ntohl( pkt.origTm_f );
00163   pkt.rxTm_s = ntohl( pkt.rxTm_s );
00164   pkt.rxTm_f = ntohl( pkt.rxTm_f );
00165   pkt.txTm_s = ntohl( pkt.txTm_s );
00166   pkt.txTm_f = ntohl( pkt.txTm_f );
00167 
00168   // see RFC 4330 p.13
00169   time_t txTm = (time_t)(pkt.txTm_s - NTP_TIMESTAMP_DELTA);  
00170   set_time(txTm); 
00171 
00172 #ifdef __DEBUG__
00173   ctTime = time(NULL);
00174   DBG("Time is now (UTC): %s", ctime(&ctTime));
00175 #endif
00176   m_sock.close();
00177 
00178   return NTP_OK;
00179 }
00180