Revision 16:c830d2e7e0f5, committed 2015-06-24

Comitter:

eunkyoungkim

Date:

Wed Jun 24 02:27:46 2015 +0000

Parent:

15:24a9f2df2145

Commit message:

Add SNTP Client

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Socket/NTPClient.cpp	Wed Jun 24 02:27:46 2015 +0000
@@ -0,0 +1,163 @@
+/* NTPClient.cpp */
+/* Copyright (C) 2012 mbed.org, MIT License
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
+ * and associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute,
+ * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or
+ * substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
+ * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+//Debug is disabled by default
+#if 0
+//Enable debug
+#define __DEBUG__
+#include <cstdio>
+#define DBG(x, ...) std::printf("[NTPClient : DBG]"x"\r\n", ##__VA_ARGS__); 
+#define WARN(x, ...) std::printf("[NTPClient : WARN]"x"\r\n", ##__VA_ARGS__); 
+#define ERR(x, ...) std::printf("[NTPClient : ERR]"x"\r\n", ##__VA_ARGS__); 
+
+#else
+//Disable debug
+#define DBG(x, ...) 
+#define WARN(x, ...)
+#define ERR(x, ...) 
+
+#endif
+
+#include "NTPClient.h"
+
+#include "UDPSocket.h"
+
+#include "mbed.h" //time() and set_time()
+
+#define NTP_PORT 123
+#define NTP_CLIENT_PORT 0 //Random port
+#define NTP_TIMESTAMP_DELTA 2208988800ull //Diff btw a UNIX timestamp (Starting Jan, 1st 1970) and a NTP timestamp (Starting Jan, 1st 1900)
+
+NTPClient::NTPClient() : m_sock()
+{
+
+
+}
+
+NTPResult NTPClient::setTime(const char* host, uint16_t port, uint32_t timeout)
+{
+#ifdef __DEBUG__
+  time_t ctTime;
+  ctTime = time(NULL);
+  DBG("Time is set to (UTC): %s", ctime(&ctTime));
+#endif
+
+  //Create & bind socket
+  DBG("Binding socket");
+  m_sock.bind(0); //Bind to a random port
+  
+  m_sock.set_blocking(false, timeout); //Set not blocking
+
+  struct NTPPacket pkt;
+
+  //Now ping the server and wait for response
+  DBG("Ping");
+  //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
+
+  pkt.rootDelay = 0; //Or this one
+  pkt.rootDispersion = 0; //Or that one
+  pkt.refId = 0; //...
+
+  pkt.refTm_s = 0;
+  pkt.origTm_s = 0;
+  pkt.rxTm_s = 0;
+  pkt.txTm_s = htonl( NTP_TIMESTAMP_DELTA + time(NULL) ); //WARN: We are in LE format, network byte order is BE
+
+  pkt.refTm_f = pkt.origTm_f = pkt.rxTm_f = pkt.txTm_f = 0;
+
+  Endpoint outEndpoint;
+  
+  if( outEndpoint.set_address(host, port) < 0)
+  {
+    m_sock.close();
+    return NTP_DNS;
+  }
+  
+  //Set timeout, non-blocking and wait using select
+  int ret = m_sock.sendTo( outEndpoint, (char*)&pkt, sizeof(NTPPacket) );
+  if (ret < 0 )
+  {
+    ERR("Could not send packet");
+    m_sock.close();
+    return NTP_CONN;
+  }
+
+  //Read response
+  Endpoint inEndpoint;
+
+  DBG("Pong");
+  do
+  {
+    ret = m_sock.receiveFrom( inEndpoint, (char*)&pkt, sizeof(NTPPacket) ); //FIXME need a DNS Resolver to actually compare the incoming address with the DNS name
+    if(ret < 0)
+    {
+      ERR("Could not receive packet");
+      m_sock.close();
+      return NTP_CONN;
+    }
+  } while( strcmp(outEndpoint.get_address(), inEndpoint.get_address()) != 0 );
+
+  if(ret < sizeof(NTPPacket)) //TODO: Accept chunks
+  {
+    ERR("Receive packet size does not match");
+    m_sock.close();
+    return NTP_PRTCL;
+  }
+
+  if( pkt.stratum == 0)  //Kiss of death message : Not good !
+  {
+    ERR("Kissed to death!");
+    m_sock.close();
+    return NTP_PRTCL;
+  }
+
+  //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 );
+
+  //Compute offset, see RFC 4330 p.13
+  uint32_t destTm_s = (NTP_TIMESTAMP_DELTA + time(NULL));
+  int64_t offset = ( (int64_t)( pkt.rxTm_s - pkt.origTm_s ) + (int64_t) ( pkt.txTm_s - destTm_s ) ) / 2; //Avoid overflow
+  DBG("Sent @%ul", pkt.txTm_s);
+  DBG("Offset: %lld", offset);
+  //Set time accordingly
+  set_time( time(NULL) + offset );
+
+#ifdef __DEBUG__
+  ctTime = time(NULL);
+  DBG("Time is now (UTC): %s", ctime(&ctTime));
+#endif
+
+  m_sock.close();
+
+  return NTP_OK;
+}
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Socket/NTPClient.h	Wed Jun 24 02:27:46 2015 +0000
@@ -0,0 +1,111 @@
+/* NTPClient.h */
+/* Copyright (C) 2012 mbed.org, MIT License
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
+ * and associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute,
+ * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or
+ * substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
+ * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/** \file
+NTP Client header file
+*/
+
+#ifndef NTPCLIENT_H_
+#define NTPCLIENT_H_
+
+#include <cstdint>
+
+using std::uint8_t;
+using std::uint16_t;
+using std::uint32_t;
+
+#include "UDPSocket.h"
+
+#define NTP_DEFAULT_PORT 123
+#define NTP_DEFAULT_TIMEOUT 4000
+
+///NTP client results
+enum NTPResult
+{
+  NTP_DNS, ///<Could not resolve name
+  NTP_PRTCL, ///<Protocol error
+  NTP_TIMEOUT, ///<Connection timeout
+  NTP_CONN, ///<Connection error
+  NTP_OK = 0, ///<Success
+};
+
+/** NTP Client to update the mbed's RTC using a remote time server
+*
+*/
+class NTPClient
+{
+public:
+  /**
+  Instantiate the NTP client
+  */
+  NTPClient();
+
+  /**Get current time (blocking)
+  Update the time using the server host
+  Blocks until completion
+  @param host NTP server IPv4 address or hostname (will be resolved via DNS)
+  @param port port to use; defaults to 123
+  @param timeout waiting timeout in ms (osWaitForever for blocking function, not recommended)
+  @return 0 on success, NTP error code (<0) on failure
+  */
+  NTPResult setTime(const char* host, uint16_t port = NTP_DEFAULT_PORT, uint32_t timeout = NTP_DEFAULT_TIMEOUT); //Blocking
+
+private:
+  struct NTPPacket //See RFC 4330 for Simple NTP
+  {
+    //WARN: We are in LE! Network is BE!
+    //LSb first
+    unsigned mode : 3;
+    unsigned vn : 3;
+    unsigned li : 2;
+
+    uint8_t stratum;
+    uint8_t poll;
+    uint8_t precision;
+    //32 bits header
+
+    uint32_t rootDelay;
+    uint32_t rootDispersion;
+    uint32_t refId;
+
+    uint32_t refTm_s;
+    uint32_t refTm_f;
+    uint32_t origTm_s;
+    uint32_t origTm_f;
+    uint32_t rxTm_s;
+    uint32_t rxTm_f;
+    uint32_t txTm_s;
+    uint32_t txTm_f;
+  } __attribute__ ((packed));
+  
+  UDPSocket m_sock;
+
+};
+typedef struct _datetime
+{
+    uint16_t yy;
+    uint8_t mo;
+    uint8_t dd;
+    uint8_t hh;
+    uint8_t mm;
+    uint8_t ss;
+} datetime;
+
+
+#endif /* NTPCLIENT_H_ */

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Socket/SNTPClient.cpp	Wed Jun 24 02:27:46 2015 +0000
@@ -0,0 +1,428 @@
+#include "SNTPClient.h"
+
+#define MAX_TRY_WRITE 20
+#define MAX_TRY_READ 10
+
+//Debug is disabled by default
+#ifdef _SNTP_DEBUG_
+#define DBG(x, ...) std::printf("[SNTPClient : DBG]"x"\r\n", ##__VA_ARGS__); 
+#define WARN(x, ...) std::printf("[SNTPClient : WARN]"x"\r\n", ##__VA_ARGS__); 
+#define ERR(x, ...) std::printf("[SNTPClient : ERR]"x"\r\n", ##__VA_ARGS__); 
+#else
+#define DBG(x, ...) 
+#define WARN(x, ...)
+#define ERR(x, ...) 
+#endif
+
+#define INFO(x, ...) printf("[SNTPClient : INFO]"x"\r\n", ##__VA_ARGS__); 
+
+SNTPClient::SNTPClient(char * url, uint8_t time_zone) {
+    memcpy(host, url, strlen(url));
+    host[strlen(url)] = '\0';
+    port = ntp_port;
+    socket.set_blocking(false, 3000);
+
+    tz = time_zone;
+}
+
+bool SNTPClient::connect() {
+    socket.init();
+    socket.bind(0);
+    if(sntp_server.set_address(host, port) < 0)
+        return false;
+
+    uint32_t ip = str_to_ip(sntp_server.get_address());
+    NTPformat.dstaddr[0] = (uint8_t)(ip >> 24);
+    NTPformat.dstaddr[1] = (uint8_t)(ip >> 16);
+    NTPformat.dstaddr[2] = (uint8_t)(ip >> 8);
+    NTPformat.dstaddr[3] = (uint8_t)(ip >> 0);
+    DBG("NTP Server: %s\r\n", sntp_server.get_address());
+
+    uint8_t Flag;
+    NTPformat.leap = 0;           /* leap indicator */
+    NTPformat.version = 4;        /* version number */
+    NTPformat.mode = 3;           /* mode */
+    NTPformat.stratum = 0;        /* stratum */
+    NTPformat.poll = 0;           /* poll interval */
+    NTPformat.precision = 0;      /* precision */
+    NTPformat.rootdelay = 0;      /* root delay */
+    NTPformat.rootdisp = 0;       /* root dispersion */
+    NTPformat.refid = 0;          /* reference ID */
+    NTPformat.reftime = 0;        /* reference time */
+    NTPformat.org = 0;            /* origin timestamp */
+    NTPformat.rec = 0;            /* receive timestamp */
+    NTPformat.xmt = 1;            /* transmit timestamp */
+
+    Flag = (NTPformat.leap<<6)+(NTPformat.version<<3)+NTPformat.mode; //one byte Flag
+    memcpy(ntpmessage,(void const*)(&Flag),1);
+
+    return true;
+}
+
+bool SNTPClient::getTime(datetime *time) {
+    uint16_t startindex = 40; //last 8-byte of data_buf[size is 48 byte] is xmt, so the startindex should be 40
+
+    socket.sendTo(sntp_server, (char *)ntpmessage, sizeof(ntpmessage));
+
+    char in_buffer[MAX_SNTP_BUF_SIZE];
+    int n = socket.receiveFrom(sntp_server, in_buffer, sizeof(in_buffer));
+
+    if(n <= 0)
+        return false;
+
+    get_seconds_from_ntp_server((uint8_t *)in_buffer,startindex);
+
+    time->yy = Nowdatetime.yy;
+    time->mo = Nowdatetime.mo;
+    time->dd = Nowdatetime.dd;
+    time->hh = Nowdatetime.hh;
+    time->mm = Nowdatetime.mm;
+    time->ss = Nowdatetime.ss;
+
+    return true;
+}
+
+bool SNTPClient::close() {
+    int ret = socket.close();
+    if (ret < 0) {
+        ERR("Could not close");
+        return false;
+    }
+    return true;
+}
+
+char* SNTPClient::getHost() {
+    return host;
+}
+
+/*
+00)UTC-12:00 Baker Island, Howland Island (both uninhabited)
+01) UTC-11:00 American Samoa, Samoa
+02) UTC-10:00 (Summer)French Polynesia (most), United States (Aleutian Islands, Hawaii)
+03) UTC-09:30 Marquesas Islands
+04) UTC-09:00 Gambier Islands;(Summer)United States (most of Alaska)
+05) UTC-08:00 (Summer)Canada (most of British Columbia), Mexico (Baja California)
+06) UTC-08:00 United States (California, most of Nevada, most of Oregon, Washington (state))
+07) UTC-07:00 Mexico (Sonora), United States (Arizona); (Summer)Canada (Alberta)
+08) UTC-07:00 Mexico (Chihuahua), United States (Colorado)
+09) UTC-06:00 Costa Rica, El Salvador, Ecuador (Galapagos Islands), Guatemala, Honduras
+10) UTC-06:00 Mexico (most), Nicaragua;(Summer)Canada (Manitoba, Saskatchewan), United States (Illinois, most of Texas)
+11) UTC-05:00 Colombia, Cuba, Ecuador (continental), Haiti, Jamaica, Panama, Peru
+12) UTC-05:00 (Summer)Canada (most of Ontario, most of Quebec)
+13) UTC-05:00 United States (most of Florida, Georgia, Massachusetts, most of Michigan, New York, North Carolina, Ohio, Washington D.C.)
+14) UTC-04:30 Venezuela
+15) UTC-04:00 Bolivia, Brazil (Amazonas), Chile (continental), Dominican Republic, Canada (Nova Scotia), Paraguay,
+16) UTC-04:00 Puerto Rico, Trinidad and Tobago
+17) UTC-03:30 Canada (Newfoundland)
+18) UTC-03:00 Argentina; (Summer) Brazil (Brasilia, Rio de Janeiro, Sao Paulo), most of Greenland, Uruguay
+19) UTC-02:00 Brazil (Fernando de Noronha), South Georgia and the South Sandwich Islands
+20) UTC-01:00 Portugal (Azores), Cape Verde
+21) UTC&#177;00:00 Cote d'Ivoire, Faroe Islands, Ghana, Iceland, Senegal; (Summer) Ireland, Portugal (continental and Madeira)
+22) UTC&#177;00:00 Spain (Canary Islands), Morocco, United Kingdom
+23) UTC+01:00 Angola, Cameroon, Nigeria, Tunisia; (Summer)Albania, Algeria, Austria, Belgium, Bosnia and Herzegovina,
+24) UTC+01:00 Spain (continental), Croatia, Czech Republic, Denmark, Germany, Hungary, Italy, Kinshasa, Kosovo,
+25) UTC+01:00 Macedonia, France (metropolitan), the Netherlands, Norway, Poland, Serbia, Slovakia, Slovenia, Sweden, Switzerland
+26) UTC+02:00 Libya, Egypt, Malawi, Mozambique, South Africa, Zambia, Zimbabwe, (Summer)Bulgaria, Cyprus, Estonia,
+27) UTC+02:00 Finland, Greece, Israel, Jordan, Latvia, Lebanon, Lithuania, Moldova, Palestine, Romania, Syria, Turkey, Ukraine
+28) UTC+03:00 Belarus, Djibouti, Eritrea, Ethiopia, Iraq, Kenya, Madagascar, Russia (Kaliningrad Oblast), Saudi Arabia,
+29) UTC+03:00 South Sudan, Sudan, Somalia, South Sudan, Tanzania, Uganda, Yemen
+30) UTC+03:30 (Summer)Iran
+31) UTC+04:00 Armenia, Azerbaijan, Georgia, Mauritius, Oman, Russia (European), Seychelles, United Arab Emirates
+32) UTC+04:30 Afghanistan
+33) UTC+05:00 Kazakhstan (West), Maldives, Pakistan, Uzbekistan
+34) UTC+05:30 India, Sri Lanka
+35) UTC+05:45 Nepal
+36) UTC+06:00 Kazakhstan (most), Bangladesh, Russia (Ural: Sverdlovsk Oblast, Chelyabinsk Oblast)
+37) UTC+06:30 Cocos Islands, Myanmar
+38) UTC+07:00 Jakarta, Russia (Novosibirsk Oblast), Thailand, Vietnam
+39) UTC+08:00 China, Hong Kong, Russia (Krasnoyarsk Krai), Malaysia, Philippines, Singapore, Taiwan, most of Mongolia, Western Australia
+40) UTC+09:00 Korea, East Timor, Russia (Irkutsk Oblast), Japan
+41) UTC+09:30 Australia (Northern Territory);(Summer)Australia (South Australia))
+42) UTC+10:00 Russia (Zabaykalsky Krai); (Summer)Australia (New South Wales, Queensland, Tasmania, Victoria)
+43) UTC+10:30 Lord Howe Island
+44) UTC+11:00 New Caledonia, Russia (Primorsky Krai), Solomon Islands
+45) UTC+11:30 Norfolk Island
+46) UTC+12:00 Fiji, Russia (Kamchatka Krai);(Summer)New Zealand
+47) UTC+12:45 (Summer)New Zealand
+48) UTC+13:00 Tonga
+49) UTC+14:00 Kiribati (Line Islands)
+*/
+void SNTPClient::get_seconds_from_ntp_server(uint8_t *buf, uint16_t idx)
+{
+    tstamp seconds = 0;
+    uint8_t i=0;
+    for (i = 0; i < 4; i++)
+    {
+        seconds = (seconds << 8) | buf[idx + i];
+    }
+    switch (tz) // Time Zone
+    {
+    case 0:
+        seconds -=  12*3600;
+        break;
+    case 1:
+        seconds -=  11*3600;
+        break;
+    case 2:
+        seconds -=  10*3600;
+        break;
+    case 3:
+        seconds -=  (9*3600+30*60);
+        break;
+    case 4:
+        seconds -=  9*3600;
+        break;
+    case 5:
+    case 6:
+        seconds -=  8*3600;
+        break;
+    case 7:
+    case 8:
+        seconds -=  7*3600;
+        break;
+    case 9:
+    case 10:
+        seconds -=  6*3600;
+        break;
+    case 11:
+    case 12:
+    case 13:
+        seconds -= 5*3600;
+        break;
+    case 14:
+        seconds -=  (4*3600+30*60);
+        break;
+    case 15:
+    case 16:
+        seconds -=  4*3600;
+        break;
+    case 17:
+        seconds -=  (3*3600+30*60);
+        break;
+    case 18:
+        seconds -=  3*3600;
+        break;
+    case 19:
+        seconds -=  2*3600;
+        break;
+    case 20:
+        seconds -=  1*3600;
+        break;
+    case 21:                            //？
+    case 22:
+        break;
+    case 23:
+    case 24:
+    case 25:
+        seconds +=  1*3600;
+        break;
+    case 26:
+    case 27:
+        seconds +=  2*3600;
+        break;
+    case 28:
+    case 29:
+        seconds +=  3*3600;
+        break;
+    case 30:
+        seconds +=  (3*3600+30*60);
+        break;
+    case 31:
+        seconds +=  4*3600;
+        break;
+    case 32:
+        seconds +=  (4*3600+30*60);
+        break;
+    case 33:
+        seconds +=  5*3600;
+        break;
+    case 34:
+        seconds +=  (5*3600+30*60);
+        break;
+    case 35:
+        seconds +=  (5*3600+45*60);
+        break;
+    case 36:
+        seconds +=  6*3600;
+        break;
+    case 37:
+        seconds +=  (6*3600+30*60);
+        break;
+    case 38:
+        seconds +=  7*3600;
+        break;
+    case 39:
+        seconds +=  8*3600;
+        break;
+    case 40:
+        seconds +=  9*3600;
+        break;
+    case 41:
+        seconds +=  (9*3600+30*60);
+        break;
+    case 42:
+        seconds +=  10*3600;
+        break;
+    case 43:
+        seconds +=  (10*3600+30*60);
+        break;
+    case 44:
+        seconds +=  11*3600;
+        break;
+    case 45:
+        seconds +=  (11*3600+30*60);
+        break;
+    case 46:
+        seconds +=  12*3600;
+        break;
+    case 47:
+        seconds +=  (12*3600+45*60);
+        break;
+    case 48:
+        seconds +=  13*3600;
+        break;
+    case 49:
+        seconds +=  14*3600;
+        break;
+
+    }
+
+    //calculation for date
+    calcdatetime(seconds);
+}
+
+void SNTPClient::calcdatetime(tstamp seconds)
+{
+    uint8_t yf=0;
+    tstamp n=0,d=0,total_d=0,rz=0;
+    uint16_t y=0,r=0,yr=0;
+    signed long long yd=0;
+
+    n = seconds;
+    total_d = seconds/(SECS_PERDAY);
+    d=0;
+    uint32_t p_year_total_sec=SECS_PERDAY*365;
+    uint32_t r_year_total_sec=SECS_PERDAY*366;
+    while(n>=p_year_total_sec)
+    {
+        if((EPOCH+r)%400==0 || ((EPOCH+r)%100!=0 && (EPOCH+r)%4==0))
+        {
+            n = n -(r_year_total_sec);
+            d = d + 366;
+        }
+        else
+        {
+            n = n - (p_year_total_sec);
+            d = d + 365;
+        }
+        r+=1;
+        y+=1;
+
+    }
+
+    y += EPOCH;
+
+    Nowdatetime.yy = y;
+
+    yd=0;
+    yd = total_d - d;
+
+    yf=1;
+    while(yd>=28)
+    {
+
+        if(yf==1 || yf==3 || yf==5 || yf==7 || yf==8 || yf==10 || yf==12)
+        {
+            yd -= 31;
+            if(yd<0)break;
+            rz += 31;
+        }
+
+        if (yf==2)
+        {
+            if (y%400==0 || (y%100!=0 && y%4==0))
+            {
+                yd -= 29;
+                if(yd<0)break;
+                rz += 29;
+            }
+            else
+            {
+                yd -= 28;
+                if(yd<0)break;
+                rz += 28;
+            }
+        }
+        if(yf==4 || yf==6 || yf==9 || yf==11 )
+        {
+            yd -= 30;
+            if(yd<0)break;
+            rz += 30;
+        }
+        yf += 1;
+
+    }
+    Nowdatetime.mo=yf;
+    yr = total_d-d-rz;
+
+    yr += 1;
+
+    Nowdatetime.dd=yr;
+
+    //calculation for time
+    seconds = seconds%SECS_PERDAY;
+    Nowdatetime.hh = seconds/3600;
+    Nowdatetime.mm = (seconds%3600)/60;
+    Nowdatetime.ss = (seconds%3600)%60;
+
+}
+
+tstamp SNTPClient::changedatetime_to_seconds(void)
+{
+    tstamp seconds=0;
+    uint32_t total_day=0;
+    uint16_t i=0,run_year_cnt=0,l=0;
+
+    l = Nowdatetime.yy;//low
+
+
+    for(i=EPOCH;i<l;i++)
+    {
+        if((i%400==0) || ((i%100!=0) && (i%4==0)))
+        {
+            run_year_cnt += 1;
+        }
+    }
+
+    total_day=(l-EPOCH-run_year_cnt)*365+run_year_cnt*366;
+
+    for(i=1;i<=Nowdatetime.mo;i++)
+    {
+        if(i==5 || i==7 || i==10 || i==12)
+        {
+            total_day += 30;
+        }
+        if (i==3)
+        {
+            if (l%400==0 && l%100!=0 && l%4==0)
+            {
+                total_day += 29;
+            }
+            else
+            {
+                total_day += 28;
+            }
+        }
+        if(i==2 || i==4 || i==6 || i==8 || i==9 || i==11)
+        {
+            total_day += 31;
+        }
+    }
+
+    seconds = (total_day+Nowdatetime.dd-1)*24*3600;
+    seconds += Nowdatetime.ss;//seconds
+    seconds += Nowdatetime.mm*60;//minute
+    seconds += Nowdatetime.hh*3600;//hour
+
+    return seconds;
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Socket/SNTPClient.h	Wed Jun 24 02:27:46 2015 +0000
@@ -0,0 +1,180 @@
+/**
+* @author Raphael Kwon
+*
+* @section LICENSE
+*
+* Copyright (c) 2014 WIZnet Co., Ltd.
+*
+* Permission is hereby granted, free of charge, to any person obtaining a copy
+* of this software and associated documentation files (the "Software"), to deal
+* in the Software without restriction, including without limitation the rights
+* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+* copies of the Software, and to permit persons to whom the Software is
+* furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included in
+* all copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+* THE SOFTWARE.
+*
+* @section DESCRIPTION
+*    Simple Network Time Protocol Client
+*
+*/
+
+#ifndef SNTPCLIENT_H
+#define SNTPCLIENT_H
+
+#include "mbed.h"
+#include "UDPSocket.h"
+
+/*
+ * @brief Define it for Debug & Monitor DNS processing.
+ * @note 
+ */
+//#define _SNTP_DEBUG_
+
+#define MAX_SNTP_BUF_SIZE   sizeof(ntpformat)       ///< maximum size of DNS buffer. */
+#define ntp_port        123                     //ntp server port number
+#define SECS_PERDAY     86400UL                 // seconds in a day = 60*60*24
+#define UTC_ADJ_HRS     9                       // SEOUL : GMT+9
+#define EPOCH           1900                    // NTP start year
+
+/* for ntpclient */
+typedef signed char s_char;
+typedef unsigned long long tstamp;
+typedef unsigned int tdist;
+
+typedef struct _ntpformat
+{
+    uint8_t  dstaddr[4];        /* destination (local) address */
+    char    version;        /* version number */
+    char    leap;           /* leap indicator */
+    char    mode;           /* mode */
+    char    stratum;        /* stratum */
+    char    poll;           /* poll interval */
+    s_char  precision;      /* precision */
+    tdist   rootdelay;      /* root delay */
+    tdist   rootdisp;       /* root dispersion */
+    char    refid;          /* reference ID */
+    tstamp  reftime;        /* reference time */
+    tstamp  org;            /* origin timestamp */
+    tstamp  rec;            /* receive timestamp */
+    tstamp  xmt;            /* transmit timestamp */
+} ntpformat;
+typedef struct _datetime
+{
+    int yy;
+    int mo;
+    int dd;
+    int hh;
+    int mm;
+    int ss;
+} datetime;
+/*
+typedef struct _datetime
+{
+    uint16_t yy;
+    uint8_t mo;
+    uint8_t dd;
+    uint8_t hh;
+    uint8_t mm;
+    uint8_t ss;
+} datetime;
+*/
+/** SNTPClient client Class.
+ *
+ * Example (ethernet network):
+ * @code
+ * #include "mbed.h"
+ * #include "EthernetInterface.h"
+ * #include "SNTPClient.h"
+ *
+ * int main() {
+ *    EthernetInterface eth;
+ *    eth.init(); //Use DHCP
+ *    eth.connect();
+ *    printf("IP Address is %s\n\r", eth.getIPAddress());
+ *   
+ *    SNTPClient ws("ws://sockets.mbed.org:443/ws/demo/rw");
+ *    ws.connect();
+ *   
+ *    while (1) {
+ *        int res = ws.send("SNTPClient Hello World!");
+ *
+ *        if (ws.read(recv)) {
+ *            printf("rcv: %s\r\n", recv);
+ *        }
+ *
+ *        wait(0.1);
+ *    }
+ * }
+ * @endcode
+ */
+
+
+class SNTPClient
+{
+    public:
+        /**
+        * Constructor
+        *
+        * @param url The SNTPClient host
+        */
+        SNTPClient(char * url, uint8_t time_zone);
+
+        /**
+        * Connect to the SNTPClient url
+        *
+        *@return true if the connection is established, false otherwise
+        */
+        bool connect();
+
+        /**
+        * Read a SNTPClient message
+        *
+        * @param message pointer to the string to be read (null if drop frame)
+        *
+        * @return true if a SNTPClient frame has been read
+        */
+        bool getTime(datetime *time);
+
+        /**
+        * Close the SNTPClient connection
+        *
+        * @return true if the connection has been closed, false otherwise
+        */
+        bool close();
+
+        /*
+        * Accessor: get host from the SNTPClient url
+        *
+        * @return host
+        */
+        char* getHost();
+
+    private:
+
+        uint16_t port;
+        char host[32];
+
+        UDPSocket socket;
+        Endpoint sntp_server;
+
+        ntpformat NTPformat;
+        datetime Nowdatetime;
+        uint8_t ntpmessage[48];
+        uint8_t tz; // Time Zone
+
+        void get_seconds_from_ntp_server(uint8_t *buf, uint16_t idx);
+        tstamp changedatetime_to_seconds(void);
+        void calcdatetime(tstamp seconds);
+};
+
+#endif