NTP

Dependents:   DISCO-F746NG_Ethernet gather_sensor_data final DISCO-F746NG_Ethernet

Files at this revision

API Documentation at this revision

Comitter:
DieterGraef
Date:
Sun Jun 19 16:24:06 2016 +0000
Commit message:
NTPClient

Changed in this revision

NTPClient.cpp Show annotated file Show diff for this revision Revisions of this file
NTPClient.h Show annotated file Show diff for this revision Revisions of this file
diff -r 000000000000 -r 584a18640e84 NTPClient.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/NTPClient.cpp	Sun Jun 19 16:24:06 2016 +0000
@@ -0,0 +1,164 @@
+/* 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;
+  // Set the inEndpoint address property
+  inEndpoint.set_address(outEndpoint.get_address(), 0);
+  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;
+}
+
diff -r 000000000000 -r 584a18640e84 NTPClient.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/NTPClient.h	Sun Jun 19 16:24:06 2016 +0000
@@ -0,0 +1,102 @@
+/* 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;
+
+};
+
+
+#endif /* NTPCLIENT_H_ */