robot arm demo team / NTPClient

Time server client - copy from iothub sample

NTPClient.cpp@0:9a7b8df5fad7, 2015-12-23 (annotated)

Committer:
henryrawas
Date:
Wed Dec 23 18:33:25 2015 +0000
Revision:
0:9a7b8df5fad7
add to robotarm;

Who changed what in which revision?

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henryrawas 0:9a7b8df5fad7 1 /* NTPClient.cpp */
henryrawas 0:9a7b8df5fad7 2 /* Copyright (C) 2012 mbed.org, MIT License
henryrawas 0:9a7b8df5fad7 3 *
henryrawas 0:9a7b8df5fad7 4 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
henryrawas 0:9a7b8df5fad7 5 * and associated documentation files (the "Software"), to deal in the Software without restriction,
henryrawas 0:9a7b8df5fad7 6 * including without limitation the rights to use, copy, modify, merge, publish, distribute,
henryrawas 0:9a7b8df5fad7 7 * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
henryrawas 0:9a7b8df5fad7 8 * furnished to do so, subject to the following conditions:
henryrawas 0:9a7b8df5fad7 9 *
henryrawas 0:9a7b8df5fad7 10 * The above copyright notice and this permission notice shall be included in all copies or
henryrawas 0:9a7b8df5fad7 11 * substantial portions of the Software.
henryrawas 0:9a7b8df5fad7 12 *
henryrawas 0:9a7b8df5fad7 13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
henryrawas 0:9a7b8df5fad7 14 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
henryrawas 0:9a7b8df5fad7 15 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
henryrawas 0:9a7b8df5fad7 16 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
henryrawas 0:9a7b8df5fad7 17 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
henryrawas 0:9a7b8df5fad7 18 */
henryrawas 0:9a7b8df5fad7 19
henryrawas 0:9a7b8df5fad7 20 //Debug is disabled by default
henryrawas 0:9a7b8df5fad7 21 #if 0
henryrawas 0:9a7b8df5fad7 22 //Enable debug
henryrawas 0:9a7b8df5fad7 23 #define __DEBUG__
henryrawas 0:9a7b8df5fad7 24 #include <cstdio>
henryrawas 0:9a7b8df5fad7 25 #define DBG(x, ...) std::printf("[NTPClient : DBG]"x"\r\n", ##__VA_ARGS__);
henryrawas 0:9a7b8df5fad7 26 #define WARN(x, ...) std::printf("[NTPClient : WARN]"x"\r\n", ##__VA_ARGS__);
henryrawas 0:9a7b8df5fad7 27 #define ERR(x, ...) std::printf("[NTPClient : ERR]"x"\r\n", ##__VA_ARGS__);
henryrawas 0:9a7b8df5fad7 28
henryrawas 0:9a7b8df5fad7 29 #else
henryrawas 0:9a7b8df5fad7 30 //Disable debug
henryrawas 0:9a7b8df5fad7 31 #define DBG(x, ...)
henryrawas 0:9a7b8df5fad7 32 #define WARN(x, ...)
henryrawas 0:9a7b8df5fad7 33 #define ERR(x, ...)
henryrawas 0:9a7b8df5fad7 34
henryrawas 0:9a7b8df5fad7 35 #endif
henryrawas 0:9a7b8df5fad7 36
henryrawas 0:9a7b8df5fad7 37 #include "NTPClient.h"
henryrawas 0:9a7b8df5fad7 38
henryrawas 0:9a7b8df5fad7 39 #include "UDPSocket.h"
henryrawas 0:9a7b8df5fad7 40
henryrawas 0:9a7b8df5fad7 41 #include "mbed.h" //time() and set_time()
henryrawas 0:9a7b8df5fad7 42
henryrawas 0:9a7b8df5fad7 43 #define NTP_PORT 123
henryrawas 0:9a7b8df5fad7 44 #define NTP_CLIENT_PORT 0 //Random port
henryrawas 0:9a7b8df5fad7 45 #define NTP_TIMESTAMP_DELTA 2208988800ull //Diff btw a UNIX timestamp (Starting Jan, 1st 1970) and a NTP timestamp (Starting Jan, 1st 1900)
henryrawas 0:9a7b8df5fad7 46
henryrawas 0:9a7b8df5fad7 47 NTPClient::NTPClient() : m_sock()
henryrawas 0:9a7b8df5fad7 48 {
henryrawas 0:9a7b8df5fad7 49
henryrawas 0:9a7b8df5fad7 50
henryrawas 0:9a7b8df5fad7 51 }
henryrawas 0:9a7b8df5fad7 52
henryrawas 0:9a7b8df5fad7 53 NTPResult NTPClient::setTime(const char* host, uint16_t port, uint32_t timeout)
henryrawas 0:9a7b8df5fad7 54 {
henryrawas 0:9a7b8df5fad7 55 #ifdef __DEBUG__
henryrawas 0:9a7b8df5fad7 56 time_t ctTime;
henryrawas 0:9a7b8df5fad7 57 ctTime = time(NULL);
henryrawas 0:9a7b8df5fad7 58 DBG("Time is set to (UTC): %s", ctime(&ctTime));
henryrawas 0:9a7b8df5fad7 59 #endif
henryrawas 0:9a7b8df5fad7 60
henryrawas 0:9a7b8df5fad7 61 //Create & bind socket
henryrawas 0:9a7b8df5fad7 62 DBG("Binding socket");
henryrawas 0:9a7b8df5fad7 63 m_sock.bind(0); //Bind to a random port
henryrawas 0:9a7b8df5fad7 64
henryrawas 0:9a7b8df5fad7 65 m_sock.set_blocking(false, timeout); //Set not blocking
henryrawas 0:9a7b8df5fad7 66
henryrawas 0:9a7b8df5fad7 67 struct NTPPacket pkt;
henryrawas 0:9a7b8df5fad7 68
henryrawas 0:9a7b8df5fad7 69 //Now ping the server and wait for response
henryrawas 0:9a7b8df5fad7 70 DBG("Ping");
henryrawas 0:9a7b8df5fad7 71 //Prepare NTP Packet:
henryrawas 0:9a7b8df5fad7 72 pkt.li = 0; //Leap Indicator : No warning
henryrawas 0:9a7b8df5fad7 73 pkt.vn = 4; //Version Number : 4
henryrawas 0:9a7b8df5fad7 74 pkt.mode = 3; //Client mode
henryrawas 0:9a7b8df5fad7 75 pkt.stratum = 0; //Not relevant here
henryrawas 0:9a7b8df5fad7 76 pkt.poll = 0; //Not significant as well
henryrawas 0:9a7b8df5fad7 77 pkt.precision = 0; //Neither this one is
henryrawas 0:9a7b8df5fad7 78
henryrawas 0:9a7b8df5fad7 79 pkt.rootDelay = 0; //Or this one
henryrawas 0:9a7b8df5fad7 80 pkt.rootDispersion = 0; //Or that one
henryrawas 0:9a7b8df5fad7 81 pkt.refId = 0; //...
henryrawas 0:9a7b8df5fad7 82
henryrawas 0:9a7b8df5fad7 83 pkt.refTm_s = 0;
henryrawas 0:9a7b8df5fad7 84 pkt.origTm_s = 0;
henryrawas 0:9a7b8df5fad7 85 pkt.rxTm_s = 0;
henryrawas 0:9a7b8df5fad7 86 pkt.txTm_s = htonl( NTP_TIMESTAMP_DELTA + time(NULL) ); //WARN: We are in LE format, network byte order is BE
henryrawas 0:9a7b8df5fad7 87
henryrawas 0:9a7b8df5fad7 88 pkt.refTm_f = pkt.origTm_f = pkt.rxTm_f = pkt.txTm_f = 0;
henryrawas 0:9a7b8df5fad7 89
henryrawas 0:9a7b8df5fad7 90 Endpoint outEndpoint;
henryrawas 0:9a7b8df5fad7 91
henryrawas 0:9a7b8df5fad7 92 if( outEndpoint.set_address(host, port) < 0)
henryrawas 0:9a7b8df5fad7 93 {
henryrawas 0:9a7b8df5fad7 94 m_sock.close();
henryrawas 0:9a7b8df5fad7 95 return NTP_DNS;
henryrawas 0:9a7b8df5fad7 96 }
henryrawas 0:9a7b8df5fad7 97
henryrawas 0:9a7b8df5fad7 98 //Set timeout, non-blocking and wait using select
henryrawas 0:9a7b8df5fad7 99 int ret = m_sock.sendTo( outEndpoint, (char*)&pkt, sizeof(NTPPacket) );
henryrawas 0:9a7b8df5fad7 100 if (ret < 0 )
henryrawas 0:9a7b8df5fad7 101 {
henryrawas 0:9a7b8df5fad7 102 ERR("Could not send packet");
henryrawas 0:9a7b8df5fad7 103 m_sock.close();
henryrawas 0:9a7b8df5fad7 104 return NTP_CONN;
henryrawas 0:9a7b8df5fad7 105 }
henryrawas 0:9a7b8df5fad7 106
henryrawas 0:9a7b8df5fad7 107 //Read response
henryrawas 0:9a7b8df5fad7 108 Endpoint inEndpoint;
henryrawas 0:9a7b8df5fad7 109
henryrawas 0:9a7b8df5fad7 110 DBG("Pong");
henryrawas 0:9a7b8df5fad7 111 do
henryrawas 0:9a7b8df5fad7 112 {
henryrawas 0:9a7b8df5fad7 113 ret = m_sock.receiveFrom( inEndpoint, (char*)&pkt, sizeof(NTPPacket) ); //FIXME need a DNS Resolver to actually compare the incoming address with the DNS name
henryrawas 0:9a7b8df5fad7 114 if(ret < 0)
henryrawas 0:9a7b8df5fad7 115 {
henryrawas 0:9a7b8df5fad7 116 ERR("Could not receive packet");
henryrawas 0:9a7b8df5fad7 117 m_sock.close();
henryrawas 0:9a7b8df5fad7 118 return NTP_CONN;
henryrawas 0:9a7b8df5fad7 119 }
henryrawas 0:9a7b8df5fad7 120 } while( strcmp(outEndpoint.get_address(), inEndpoint.get_address()) != 0 );
henryrawas 0:9a7b8df5fad7 121
henryrawas 0:9a7b8df5fad7 122 if(ret < sizeof(NTPPacket)) //TODO: Accept chunks
henryrawas 0:9a7b8df5fad7 123 {
henryrawas 0:9a7b8df5fad7 124 ERR("Receive packet size does not match");
henryrawas 0:9a7b8df5fad7 125 m_sock.close();
henryrawas 0:9a7b8df5fad7 126 return NTP_PRTCL;
henryrawas 0:9a7b8df5fad7 127 }
henryrawas 0:9a7b8df5fad7 128
henryrawas 0:9a7b8df5fad7 129 if( pkt.stratum == 0) //Kiss of death message : Not good !
henryrawas 0:9a7b8df5fad7 130 {
henryrawas 0:9a7b8df5fad7 131 ERR("Kissed to death!");
henryrawas 0:9a7b8df5fad7 132 m_sock.close();
henryrawas 0:9a7b8df5fad7 133 return NTP_PRTCL;
henryrawas 0:9a7b8df5fad7 134 }
henryrawas 0:9a7b8df5fad7 135
henryrawas 0:9a7b8df5fad7 136 //Correct Endianness
henryrawas 0:9a7b8df5fad7 137 pkt.refTm_s = ntohl( pkt.refTm_s );
henryrawas 0:9a7b8df5fad7 138 pkt.refTm_f = ntohl( pkt.refTm_f );
henryrawas 0:9a7b8df5fad7 139 pkt.origTm_s = ntohl( pkt.origTm_s );
henryrawas 0:9a7b8df5fad7 140 pkt.origTm_f = ntohl( pkt.origTm_f );
henryrawas 0:9a7b8df5fad7 141 pkt.rxTm_s = ntohl( pkt.rxTm_s );
henryrawas 0:9a7b8df5fad7 142 pkt.rxTm_f = ntohl( pkt.rxTm_f );
henryrawas 0:9a7b8df5fad7 143 pkt.txTm_s = ntohl( pkt.txTm_s );
henryrawas 0:9a7b8df5fad7 144 pkt.txTm_f = ntohl( pkt.txTm_f );
henryrawas 0:9a7b8df5fad7 145
henryrawas 0:9a7b8df5fad7 146 //Compute offset, see RFC 4330 p.13
henryrawas 0:9a7b8df5fad7 147 uint32_t destTm_s = (NTP_TIMESTAMP_DELTA + time(NULL));
henryrawas 0:9a7b8df5fad7 148 int64_t offset = ( (int64_t)( pkt.rxTm_s - pkt.origTm_s ) + (int64_t) ( pkt.txTm_s - destTm_s ) ) / 2; //Avoid overflow
henryrawas 0:9a7b8df5fad7 149 DBG("Sent @%ul", pkt.txTm_s);
henryrawas 0:9a7b8df5fad7 150 DBG("Offset: %lld", offset);
henryrawas 0:9a7b8df5fad7 151 //Set time accordingly
henryrawas 0:9a7b8df5fad7 152 set_time( time(NULL) + offset );
henryrawas 0:9a7b8df5fad7 153
henryrawas 0:9a7b8df5fad7 154 #ifdef __DEBUG__
henryrawas 0:9a7b8df5fad7 155 ctTime = time(NULL);
henryrawas 0:9a7b8df5fad7 156 DBG("Time is now (UTC): %s", ctime(&ctTime));
henryrawas 0:9a7b8df5fad7 157 #endif
henryrawas 0:9a7b8df5fad7 158
henryrawas 0:9a7b8df5fad7 159 m_sock.close();
henryrawas 0:9a7b8df5fad7 160
henryrawas 0:9a7b8df5fad7 161 return NTP_OK;
henryrawas 0:9a7b8df5fad7 162 }
henryrawas 0:9a7b8df5fad7 163