Diff: NTPclient.cpp

Revision:

0:3854dc7bd4de

Child:

1:a97d143dd94e

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/NTPclient.cpp	Sun Mar 08 14:32:36 2020 +0000
@@ -0,0 +1,125 @@
+
+#include "NTPclient.h"
+
+#define NTP_PORT 123
+#define NTP_CLIENT_PORT 0 //Random port
+#define timeout 3000
+#define NTP_TIMESTAMP_DELTA 2208988800ull 
+// Diff btw a UNIX timestamp (Starting Jan, 1st 1970)
+// and a NTP timestamp (Starting Jan, 1st 1900)
+
+NTPclient::NTPclient(NetworkInterface & _m_intf) : m_intf(_m_intf)
+{
+}
+#ifdef htons
+#undef htons
+#endif /* htons */
+#ifdef htonl
+#undef htonl
+#endif /* htonl */
+#ifdef ntohs
+#undef ntohs
+#endif /* ntohs */
+#ifdef ntohl
+#undef ntohl
+#endif /* ntohl */
+
+
+#if ((__BYTE_ORDER__) == (__ORDER_LITTLE_ENDIAN__))
+
+#define htons(x) ((((x) & 0xff) << 8) | (((x) & 0xff00) >> 8))
+#define ntohs(x) htons(x)
+#define htonl(x) ((((x) & 0xff) << 24) | \
+                     (((x) & 0xff00) << 8) | \
+                     (((x) & 0xff0000UL) >> 8) | \
+                     (((x) & 0xff000000UL) >> 24))
+#define ntohl(x) htonl(x)
+
+#else
+
+#define htons(x)  (x)
+#define htonl(x)  (x)
+#define ntohl(x)  (x)
+#define ntohs(x)  (x)
+
+#endif 
+
+uint32_t NTPclient::getNTP(const char * NTPpool, uint32_t tzoffset, bool dst, bool setRTC)
+
+{
+  SocketAddress address(0, NTP_PORT);
+  int r = m_intf.gethostbyname(NTPpool, &address);  
+  if (r) {
+        printf("error: 'gethostbyname(\"%s\")' failed with code %d\r\n", NTPpool, r);
+    } else if (!address) {
+        printf("error: 'gethostbyname(\"%s\")' returned null IP address\r\n", NTPpool);
+    }  
+   
+  //Create & bind socket
+  if (m_sock.open(&m_intf) < 0) printf ("ERROR sock open \n\r");  
+  m_sock.set_timeout(timeout);  
+
+  struct NTPPacket pkt;  
+  memset (&pkt, 0, sizeof(NTPPacket));   
+
+  //Now ping the server and wait for response
+  //Prepare NTP Packet:
+  pkt.li = 0;           //Leap Indicator : No warning
+  pkt.vn = 4;           //Version Number : 4
+  pkt.mode = 3;         //Client mode
+  pkt.stratum = 0;      //Not relevant here
+  pkt.poll = 0;         //Not significant as well
+  pkt.precision = 0;    //Neither this one is
+
+    int ret = m_sock.sendto(address, (char*)&pkt, sizeof(NTPPacket) ); 
+    if (ret < 0 ){
+        m_sock.close();
+        return 0;
+    }
+    //Read response
+    ret = m_sock.recvfrom(&address, (char*)&pkt, sizeof(NTPPacket) );
+    if(ret < 0){
+        m_sock.close();
+        return 0;
+        }
+    if(ret < sizeof(NTPPacket)){
+        m_sock.close();
+        return 0;
+        }
+    //Correct Endianness
+    pkt.refTm_s = ntohl( pkt.refTm_s ); 
+    pkt.refTm_f = ntohl( pkt.refTm_f );
+    pkt.origTm_s = ntohl( pkt.origTm_s );
+    pkt.origTm_f = ntohl( pkt.origTm_f );
+    pkt.rxTm_s = ntohl( pkt.rxTm_s );
+    pkt.rxTm_f = ntohl( pkt.rxTm_f );
+    pkt.txTm_s = ntohl( pkt.txTm_s );
+    pkt.txTm_f = ntohl( pkt.txTm_f );
+    
+    
+    uint32_t CETtime = (time_t)(pkt.txTm_s - NTP_TIMESTAMP_DELTA + tzoffset); 
+    // check for DST time change, only valid for europe!!!
+    uint32_t DST=0;  
+    if(dst){
+        uint32_t dow,hour,day,month;             
+        char buffer[10];        
+        strftime(buffer, 2,"%H", localtime(&CETtime));                                
+        hour = atoi(buffer);
+        strftime(buffer, 2,"%w", localtime(&CETtime));                                
+        dow = atoi(buffer);
+        strftime(buffer, 2,"%e", localtime(&CETtime));                
+        day = atoi(buffer);
+        strftime(buffer, 2,"%m", localtime(&CETtime));
+        month = atoi(buffer);       
+        
+        uint32_t previousSunday = day - dow;
+        if (month > 2 && month < 9){DST=3600;}
+        // DST starts 2nd Sunday of March;  2am            
+        if (month == 2 && previousSunday >= 25 && hour >= 2){DST=3600;}
+        // DST ends 1st Sunday of November; 2am
+        if (month == 9 && previousSunday < 25 && hour >= 2){DST=0;}
+    }            
+    if(setRTC){set_time(CETtime+DST+1);} // add extra second here for processing         
+    m_sock.close();
+    return (CETtime+DST+1);
+}