NTP Client for the mbed networking libraries. The small change to this version is that there can be only one cause for the return value zero.
Fork of NTPClient by
NTPClient.cpp@9:2f607bafc29e, 2016-01-16 (annotated)
- Committer:
- WiredHome
- Date:
- Sat Jan 16 20:47:33 2016 +0000
- Revision:
- 9:2f607bafc29e
- Parent:
- 8:802277794640
NTPClient was computing the offset from the server to the client incorrectly (when it was promoting 32 to 64bit values. The result was time-jumps (e.g. from 2016 to 2084) and then back. This was most noticeable with the WiFly interface (extra delays)
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
donatien | 0:04a82df0f587 | 1 | /* NTPClient.cpp */ |
donatien | 2:9a64a50df235 | 2 | /* Copyright (C) 2012 mbed.org, MIT License |
donatien | 2:9a64a50df235 | 3 | * |
donatien | 2:9a64a50df235 | 4 | * Permission is hereby granted, free of charge, to any person obtaining a copy of this software |
donatien | 2:9a64a50df235 | 5 | * and associated documentation files (the "Software"), to deal in the Software without restriction, |
donatien | 2:9a64a50df235 | 6 | * including without limitation the rights to use, copy, modify, merge, publish, distribute, |
donatien | 2:9a64a50df235 | 7 | * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is |
donatien | 2:9a64a50df235 | 8 | * furnished to do so, subject to the following conditions: |
donatien | 2:9a64a50df235 | 9 | * |
donatien | 2:9a64a50df235 | 10 | * The above copyright notice and this permission notice shall be included in all copies or |
donatien | 2:9a64a50df235 | 11 | * substantial portions of the Software. |
donatien | 2:9a64a50df235 | 12 | * |
donatien | 2:9a64a50df235 | 13 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING |
donatien | 2:9a64a50df235 | 14 | * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
donatien | 2:9a64a50df235 | 15 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, |
donatien | 2:9a64a50df235 | 16 | * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
donatien | 2:9a64a50df235 | 17 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
donatien | 2:9a64a50df235 | 18 | */ |
WiredHome | 9:2f607bafc29e | 19 | #include "mbed.h" //time() and set_time() |
donatien | 0:04a82df0f587 | 20 | |
WiredHome | 9:2f607bafc29e | 21 | //#define DEBUG "NTPc" |
WiredHome | 9:2f607bafc29e | 22 | |
WiredHome | 9:2f607bafc29e | 23 | #if (defined(DEBUG)) |
donatien | 2:9a64a50df235 | 24 | #include <cstdio> |
WiredHome | 9:2f607bafc29e | 25 | #define INFO(x, ...) std::printf("[INF %s %4d] "x"\r\n", DEBUG, __LINE__, ##__VA_ARGS__); |
WiredHome | 9:2f607bafc29e | 26 | #define WARN(x, ...) std::printf("[WRN %s %4d] "x"\r\n", DEBUG, __LINE__, ##__VA_ARGS__); |
WiredHome | 9:2f607bafc29e | 27 | #define ERR(x, ...) std::printf("[ERR %s %4d] "x"\r\n", DEBUG, __LINE__, ##__VA_ARGS__); |
WiredHome | 9:2f607bafc29e | 28 | static void HexDump(const char * title, const uint8_t * p, int count) |
WiredHome | 9:2f607bafc29e | 29 | { |
WiredHome | 9:2f607bafc29e | 30 | int i; |
WiredHome | 9:2f607bafc29e | 31 | char buf[100] = "0000: "; |
WiredHome | 9:2f607bafc29e | 32 | |
WiredHome | 9:2f607bafc29e | 33 | if (*title) |
WiredHome | 9:2f607bafc29e | 34 | INFO("%s", title); |
WiredHome | 9:2f607bafc29e | 35 | for (i=0; i<count; ) { |
WiredHome | 9:2f607bafc29e | 36 | sprintf(buf + strlen(buf), "%02X ", *(p+i)); |
WiredHome | 9:2f607bafc29e | 37 | if ((++i & 0x0F) == 0x00) { |
WiredHome | 9:2f607bafc29e | 38 | INFO("%s", buf); |
WiredHome | 9:2f607bafc29e | 39 | if (i < count) |
WiredHome | 9:2f607bafc29e | 40 | sprintf(buf, "%04X: ", i); |
WiredHome | 9:2f607bafc29e | 41 | else |
WiredHome | 9:2f607bafc29e | 42 | buf[0] = '\0'; |
WiredHome | 9:2f607bafc29e | 43 | } |
WiredHome | 9:2f607bafc29e | 44 | } |
WiredHome | 9:2f607bafc29e | 45 | if (strlen(buf)) |
WiredHome | 9:2f607bafc29e | 46 | INFO("%s", buf); |
WiredHome | 9:2f607bafc29e | 47 | } |
donatien | 2:9a64a50df235 | 48 | #else |
donatien | 2:9a64a50df235 | 49 | //Disable debug |
WiredHome | 9:2f607bafc29e | 50 | #define INFO(x, ...) |
donatien | 2:9a64a50df235 | 51 | #define WARN(x, ...) |
WiredHome | 8:802277794640 | 52 | #define ERR(x, ...) |
WiredHome | 9:2f607bafc29e | 53 | #define HexDump(a,b,c) |
donatien | 0:04a82df0f587 | 54 | #endif |
donatien | 0:04a82df0f587 | 55 | |
donatien | 0:04a82df0f587 | 56 | #include "NTPClient.h" |
donatien | 0:04a82df0f587 | 57 | |
donatien | 1:b221a8765b3f | 58 | #include "UDPSocket.h" |
donatien | 1:b221a8765b3f | 59 | |
donatien | 0:04a82df0f587 | 60 | |
donatien | 0:04a82df0f587 | 61 | #define NTP_PORT 123 |
donatien | 0:04a82df0f587 | 62 | #define NTP_CLIENT_PORT 0 //Random port |
donatien | 0:04a82df0f587 | 63 | #define NTP_TIMESTAMP_DELTA 2208988800ull //Diff btw a UNIX timestamp (Starting Jan, 1st 1970) and a NTP timestamp (Starting Jan, 1st 1900) |
donatien | 0:04a82df0f587 | 64 | |
donatien | 2:9a64a50df235 | 65 | NTPClient::NTPClient() : m_sock() |
donatien | 0:04a82df0f587 | 66 | { |
donatien | 0:04a82df0f587 | 67 | |
donatien | 0:04a82df0f587 | 68 | } |
donatien | 0:04a82df0f587 | 69 | |
donatien | 2:9a64a50df235 | 70 | NTPResult NTPClient::setTime(const char* host, uint16_t port, uint32_t timeout) |
donatien | 0:04a82df0f587 | 71 | { |
WiredHome | 9:2f607bafc29e | 72 | #ifdef DEBUG |
WiredHome | 8:802277794640 | 73 | time_t ctTime; |
WiredHome | 8:802277794640 | 74 | ctTime = time(NULL); |
WiredHome | 9:2f607bafc29e | 75 | INFO("Time is currently (UTC): %s", ctime(&ctTime)); |
donatien | 0:04a82df0f587 | 76 | #endif |
donatien | 0:04a82df0f587 | 77 | |
WiredHome | 8:802277794640 | 78 | //Create & bind socket |
WiredHome | 9:2f607bafc29e | 79 | INFO("Binding socket"); |
WiredHome | 8:802277794640 | 80 | m_sock.bind(0); //Bind to a random port |
donatien | 0:04a82df0f587 | 81 | |
WiredHome | 8:802277794640 | 82 | m_sock.set_blocking(false, timeout); //Set not blocking |
WiredHome | 8:802277794640 | 83 | |
WiredHome | 8:802277794640 | 84 | struct NTPPacket pkt; |
donatien | 0:04a82df0f587 | 85 | |
WiredHome | 8:802277794640 | 86 | //Now ping the server and wait for response |
WiredHome | 9:2f607bafc29e | 87 | INFO("Ping"); |
WiredHome | 8:802277794640 | 88 | //Prepare NTP Packet: |
WiredHome | 8:802277794640 | 89 | pkt.li = 0; //Leap Indicator : No warning |
WiredHome | 8:802277794640 | 90 | pkt.vn = 4; //Version Number : 4 |
WiredHome | 8:802277794640 | 91 | pkt.mode = 3; //Client mode |
WiredHome | 8:802277794640 | 92 | pkt.stratum = 0; //Not relevant here |
WiredHome | 8:802277794640 | 93 | pkt.poll = 0; //Not significant as well |
WiredHome | 8:802277794640 | 94 | pkt.precision = 0; //Neither this one is |
donatien | 0:04a82df0f587 | 95 | |
WiredHome | 8:802277794640 | 96 | pkt.rootDelay = 0; //Or this one |
WiredHome | 8:802277794640 | 97 | pkt.rootDispersion = 0; //Or that one |
WiredHome | 8:802277794640 | 98 | pkt.refId = 0; //... |
donatien | 0:04a82df0f587 | 99 | |
WiredHome | 8:802277794640 | 100 | pkt.refTm_s = 0; |
WiredHome | 8:802277794640 | 101 | pkt.origTm_s = 0; |
WiredHome | 8:802277794640 | 102 | pkt.rxTm_s = 0; |
WiredHome | 8:802277794640 | 103 | pkt.txTm_s = htonl( NTP_TIMESTAMP_DELTA + time(NULL) ); //WARN: We are in LE format, network byte order is BE |
WiredHome | 9:2f607bafc29e | 104 | INFO("pkt.txTm_s = %u", ntohl(pkt.txTm_s) ); |
WiredHome | 8:802277794640 | 105 | pkt.refTm_f = pkt.origTm_f = pkt.rxTm_f = pkt.txTm_f = 0; |
WiredHome | 8:802277794640 | 106 | |
WiredHome | 9:2f607bafc29e | 107 | HexDump("NTP Post", (uint8_t *)&pkt, sizeof(NTPPacket)); |
WiredHome | 9:2f607bafc29e | 108 | |
WiredHome | 8:802277794640 | 109 | Endpoint outEndpoint; |
WiredHome | 9:2f607bafc29e | 110 | INFO("outEndpoint instantiated"); |
WiredHome | 9:2f607bafc29e | 111 | |
WiredHome | 8:802277794640 | 112 | if( outEndpoint.set_address(host, port) < 0) { |
WiredHome | 8:802277794640 | 113 | m_sock.close(); |
WiredHome | 8:802277794640 | 114 | return NTP_DNS; |
WiredHome | 8:802277794640 | 115 | } |
WiredHome | 9:2f607bafc29e | 116 | INFO("outEndpoint: %s:%d", outEndpoint.get_address(), outEndpoint.get_port()); |
WiredHome | 8:802277794640 | 117 | |
WiredHome | 8:802277794640 | 118 | //Set timeout, non-blocking and wait using select |
WiredHome | 8:802277794640 | 119 | int ret = m_sock.sendTo( outEndpoint, (char*)&pkt, sizeof(NTPPacket) ); |
WiredHome | 8:802277794640 | 120 | if (ret < 0 ) { |
WiredHome | 8:802277794640 | 121 | ERR("Could not send packet"); |
WiredHome | 8:802277794640 | 122 | m_sock.close(); |
WiredHome | 8:802277794640 | 123 | return NTP_CONN; |
WiredHome | 8:802277794640 | 124 | } |
donatien | 0:04a82df0f587 | 125 | |
WiredHome | 8:802277794640 | 126 | //Read response |
WiredHome | 8:802277794640 | 127 | Endpoint inEndpoint; |
WiredHome | 9:2f607bafc29e | 128 | INFO(" inEndpoint instantiated: %s.", inEndpoint.get_address()); |
WiredHome | 9:2f607bafc29e | 129 | |
WiredHome | 8:802277794640 | 130 | // Set the inEndpoint address property |
WiredHome | 8:802277794640 | 131 | inEndpoint.set_address(outEndpoint.get_address(), 0); |
donatien | 2:9a64a50df235 | 132 | |
WiredHome | 9:2f607bafc29e | 133 | INFO(" inEndpoint: %s", inEndpoint.get_address()); |
WiredHome | 9:2f607bafc29e | 134 | |
WiredHome | 9:2f607bafc29e | 135 | INFO("Pong"); |
WiredHome | 9:2f607bafc29e | 136 | int loopLimit = 20; // semi-randomly selected so it doesn't hang forever here... |
WiredHome | 8:802277794640 | 137 | do { |
WiredHome | 9:2f607bafc29e | 138 | ret = m_sock.receiveFrom( inEndpoint, (char*)&pkt, sizeof(NTPPacket) ); |
WiredHome | 8:802277794640 | 139 | if(ret < 0) { |
WiredHome | 8:802277794640 | 140 | ERR("Could not receive packet"); |
WiredHome | 8:802277794640 | 141 | m_sock.close(); |
WiredHome | 8:802277794640 | 142 | return NTP_CONN; |
WiredHome | 8:802277794640 | 143 | } |
WiredHome | 9:2f607bafc29e | 144 | INFO("."); |
WiredHome | 9:2f607bafc29e | 145 | loopLimit--; |
WiredHome | 9:2f607bafc29e | 146 | } while( strcmp(outEndpoint.get_address(), inEndpoint.get_address()) != 0 && loopLimit > 0); |
WiredHome | 8:802277794640 | 147 | |
WiredHome | 8:802277794640 | 148 | if(ret < (int)sizeof(NTPPacket)) { //TODO: Accept chunks |
WiredHome | 8:802277794640 | 149 | ERR("Receive packet size does not match"); |
WiredHome | 8:802277794640 | 150 | m_sock.close(); |
WiredHome | 8:802277794640 | 151 | return NTP_PRTCL; |
donatien | 0:04a82df0f587 | 152 | } |
donatien | 0:04a82df0f587 | 153 | |
WiredHome | 8:802277794640 | 154 | if( pkt.stratum == 0) { //Kiss of death message : Not good ! |
WiredHome | 8:802277794640 | 155 | ERR("Kissed to death!"); |
WiredHome | 8:802277794640 | 156 | m_sock.close(); |
WiredHome | 8:802277794640 | 157 | return NTP_PRTCL; |
WiredHome | 8:802277794640 | 158 | } |
donatien | 0:04a82df0f587 | 159 | |
WiredHome | 9:2f607bafc29e | 160 | HexDump("NTP Info", (uint8_t *)&pkt, sizeof(NTPPacket)); |
WiredHome | 9:2f607bafc29e | 161 | |
WiredHome | 8:802277794640 | 162 | //Correct Endianness |
WiredHome | 8:802277794640 | 163 | pkt.refTm_s = ntohl( pkt.refTm_s ); |
WiredHome | 8:802277794640 | 164 | pkt.refTm_f = ntohl( pkt.refTm_f ); |
WiredHome | 8:802277794640 | 165 | pkt.origTm_s = ntohl( pkt.origTm_s ); |
WiredHome | 8:802277794640 | 166 | pkt.origTm_f = ntohl( pkt.origTm_f ); |
WiredHome | 8:802277794640 | 167 | pkt.rxTm_s = ntohl( pkt.rxTm_s ); |
WiredHome | 8:802277794640 | 168 | pkt.rxTm_f = ntohl( pkt.rxTm_f ); |
WiredHome | 8:802277794640 | 169 | pkt.txTm_s = ntohl( pkt.txTm_s ); |
WiredHome | 8:802277794640 | 170 | pkt.txTm_f = ntohl( pkt.txTm_f ); |
donatien | 0:04a82df0f587 | 171 | |
WiredHome | 8:802277794640 | 172 | //Compute offset, see RFC 4330 p.13 |
WiredHome | 8:802277794640 | 173 | uint32_t destTm_s = (NTP_TIMESTAMP_DELTA + time(NULL)); |
WiredHome | 9:2f607bafc29e | 174 | INFO("destTm_s = %u", destTm_s); |
WiredHome | 9:2f607bafc29e | 175 | INFO("pkt.txTm_s = %u", pkt.txTm_s ); |
WiredHome | 9:2f607bafc29e | 176 | |
WiredHome | 9:2f607bafc29e | 177 | // Modification by David Smart |
WiredHome | 9:2f607bafc29e | 178 | // The setTime function was computing the offset incorrectly as the value was promoted to 64-bit. |
WiredHome | 9:2f607bafc29e | 179 | // The side effect was that a negative offset ended up as a very large positive (e.g. jump from |
WiredHome | 9:2f607bafc29e | 180 | // 2016 to 2084). This change revises that computation. |
WiredHome | 9:2f607bafc29e | 181 | int64_t offset = ( ((int64_t)pkt.rxTm_s - pkt.origTm_s ) + ((int64_t) pkt.txTm_s - destTm_s ) ) / 2; //Avoid overflow |
WiredHome | 9:2f607bafc29e | 182 | |
WiredHome | 9:2f607bafc29e | 183 | // delay is not needed, this was for diagnostic purposes only. |
WiredHome | 9:2f607bafc29e | 184 | //int64_t delay = ((int64_t) destTm_s - pkt.origTm_s) - ((int64_t) pkt.txTm_s - pkt.rxTm_s); |
WiredHome | 9:2f607bafc29e | 185 | INFO("txTm_s @%u", pkt.txTm_s); |
WiredHome | 9:2f607bafc29e | 186 | INFO("origTm_s @%u", pkt.origTm_s); |
WiredHome | 9:2f607bafc29e | 187 | INFO("rxTm_s @%u", pkt.rxTm_s); |
WiredHome | 9:2f607bafc29e | 188 | INFO("destTm_s @%u", destTm_s); |
WiredHome | 9:2f607bafc29e | 189 | INFO("Offset: %lld", offset); |
WiredHome | 9:2f607bafc29e | 190 | //INFO("Delay: %lld", delay); |
WiredHome | 9:2f607bafc29e | 191 | |
WiredHome | 9:2f607bafc29e | 192 | INFO(" time: %u", time(NULL)); |
WiredHome | 8:802277794640 | 193 | //Set time accordingly |
WiredHome | 8:802277794640 | 194 | set_time( time(NULL) + offset ); |
donatien | 0:04a82df0f587 | 195 | |
donatien | 2:9a64a50df235 | 196 | #ifdef __DEBUG__ |
WiredHome | 8:802277794640 | 197 | ctTime = time(NULL); |
WiredHome | 9:2f607bafc29e | 198 | INFO("Time is now (UTC): %s", ctime(&ctTime)); |
donatien | 0:04a82df0f587 | 199 | #endif |
donatien | 0:04a82df0f587 | 200 | |
WiredHome | 8:802277794640 | 201 | m_sock.close(); |
donatien | 0:04a82df0f587 | 202 | |
WiredHome | 8:802277794640 | 203 | return NTP_OK; |
donatien | 0:04a82df0f587 | 204 | } |
donatien | 0:04a82df0f587 | 205 |