SimpleNTP.cpp

00001 #include "SimpleNTP.h"
00002 
00003 SimpleNTP::Result SimpleNTP::setNTPServer(string _server, unsigned short _port)
00004 {
00005     server= _server;
00006     port= _port;
00007 
00008     socket.set_blocking(false, 1500);
00009     if(socket.init() == -1)
00010         return ERR_SocketInit;
00011 
00012     if(serverNTP.set_address(server.c_str(), port) == -1)
00013         return ERR_SetNTPAddr;
00014 
00015     return SUCCESS;
00016 }
00017 
00018 long SimpleNTP::getNetworkTime()
00019 {
00020 //    long timeEpoch= -1;
00021     int idx, bytes;
00022 // LeapIndicator:0(0x00), VersionNumber:4(0x100), Mode:3(0x011);
00023 // -> 0b0010 0011 = 0x23
00024     char req[49];
00025     for(idx= 0; idx < 48; idx++)
00026         req[idx]= 0x00;
00027     req[48]= NULL;
00028     req[0]= 0x23;
00029     bytes= socket.sendTo(serverNTP, (char *)req, 48);
00030     if(bytes == -1)
00031         return -1;
00032 
00033 // NTP response is max 68 Byte (EXPECTED).
00034     char resSNTP[70];
00035     bytes= socket.receiveFrom(serverNTP, resSNTP, sizeof(resSNTP));
00036     if(bytes == -1)
00037         return -1;
00038 
00039     // RFC2030; Transmit TimeStamp[40-48Byte]:BigEndian 32bit unsigned long (dec), + 32bit under floating-point.
00040     unsigned long timeNTP= 0;
00041     for(idx = 0; idx < 4; idx++)
00042         timeNTP= (timeNTP << 8) | resSNTP[40+ idx];
00043 
00044 // 　25567day * 24h * 60m * 60s = 2208988800 s. w/o leap seconds(DEFINED).
00045 // Epoch: 1970/01/01~. NTP:1900/01/01~
00046 //    timeEpoch= timeNTP- 2208988800;
00047     return timeNTP- 2208988800;//timeEpoch;
00048 }
00049 
00050 SimpleNTP::Result SimpleNTP::close()
00051 {
00052     if(socket.close() == -1)
00053         return ERR_SocketClose;
00054 
00055     return SUCCESS;
00056 }
00057 
00058 // EOF