2 /* Copyright (C) 2012 mbed.org, MIT License
4 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
5 * and associated documentation files (the "Software"), to deal in the Software without restriction,
6 * including without limitation the rights to use, copy, modify, merge, publish, distribute,
7 * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
8 * furnished to do so, subject to the following conditions:
10 * The above copyright notice and this permission notice shall be included in all copies or
11 * substantial portions of the Software.
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
14 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
15 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
16 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
17 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
20 //Debug is disabled by default
25 #define DBG(x, ...) std::printf("[NTPClient : DBG]"x"\r\n", ##__VA_ARGS__);
26 #define WARN(x, ...) std::printf("[NTPClient : WARN]"x"\r\n", ##__VA_ARGS__);
27 #define ERR(x, ...) std::printf("[NTPClient : ERR]"x"\r\n", ##__VA_ARGS__);
37 #include "NTPClient.h"
39 #include "UDPSocket.h"
41 #include "mbed.h" //time() and set_time()
44 #define NTP_CLIENT_PORT 0 //Random port
45 #define NTP_TIMESTAMP_DELTA 2208988800ull //Diff btw a UNIX timestamp (Starting Jan, 1st 1970) and a NTP timestamp (Starting Jan, 1st 1900)
47 NTPClient::NTPClient() : m_sock()
53 NTPResult NTPClient::setTime(const char* host, uint16_t port, uint32_t timeout)
58 DBG("Time is set to (UTC): %s", ctime(&ctTime));
61 //Create & bind socket
62 DBG("Binding socket");
63 m_sock.bind(0); //Bind to a random port
65 m_sock.set_blocking(false, timeout); //Set not blocking
69 //Now ping the server and wait for response
72 pkt.li = 0; //Leap Indicator : No warning
73 pkt.vn = 4; //Version Number : 4
74 pkt.mode = 3; //Client mode
75 pkt.stratum = 0; //Not relevant here
76 pkt.poll = 0; //Not significant as well
77 pkt.precision = 0; //Neither this one is
79 pkt.rootDelay = 0; //Or this one
80 pkt.rootDispersion = 0; //Or that one
86 pkt.txTm_s = htonl( NTP_TIMESTAMP_DELTA + time(NULL) ); //WARN: We are in LE format, network byte order is BE
88 pkt.refTm_f = pkt.origTm_f = pkt.rxTm_f = pkt.txTm_f = 0;
92 if( outEndpoint.set_address(host, port) < 0)
98 //Set timeout, non-blocking and wait using select
99 int ret = m_sock.sendTo( outEndpoint, (char*)&pkt, sizeof(NTPPacket) );
102 ERR("Could not send packet");
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
116 ERR("Could not receive packet");
120 } while( strcmp(outEndpoint.get_address(), inEndpoint.get_address()) != 0 );
122 if(ret < sizeof(NTPPacket)) //TODO: Accept chunks
124 ERR("Receive packet size does not match");
129 if( pkt.stratum == 0) //Kiss of death message : Not good !
131 ERR("Kissed to death!");
137 pkt.refTm_s = ntohl( pkt.refTm_s );
138 pkt.refTm_f = ntohl( pkt.refTm_f );
139 pkt.origTm_s = ntohl( pkt.origTm_s );
140 pkt.origTm_f = ntohl( pkt.origTm_f );
141 pkt.rxTm_s = ntohl( pkt.rxTm_s );
142 pkt.rxTm_f = ntohl( pkt.rxTm_f );
143 pkt.txTm_s = ntohl( pkt.txTm_s );
144 pkt.txTm_f = ntohl( pkt.txTm_f );
146 //Compute offset, see RFC 4330 p.13
147 uint32_t destTm_s = (NTP_TIMESTAMP_DELTA + time(NULL));
148 int64_t offset = ( (int64_t)( pkt.rxTm_s - pkt.origTm_s ) + (int64_t) ( pkt.txTm_s - destTm_s ) ) / 2; //Avoid overflow
149 DBG("Sent @%ul", pkt.txTm_s);
150 DBG("Offset: %lld", offset);
151 //Set time accordingly
152 set_time( time(NULL) + offset );
156 DBG("Time is now (UTC): %s", ctime(&ctTime));