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@1:b221a8765b3f, 2012-07-27 (annotated)
- Committer:
- donatien
- Date:
- Fri Jul 27 08:49:34 2012 +0000
- Revision:
- 1:b221a8765b3f
- Parent:
- 0:04a82df0f587
- Child:
- 2:9a64a50df235
Initial commit;
Who changed what in which revision?
User | Revision | Line number | New contents of line |
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donatien | 0:04a82df0f587 | 1 | /* NTPClient.cpp */ |
donatien | 0:04a82df0f587 | 2 | /* |
donatien | 0:04a82df0f587 | 3 | Copyright (C) 2012 ARM Limited. |
donatien | 0:04a82df0f587 | 4 | |
donatien | 0:04a82df0f587 | 5 | Permission is hereby granted, free of charge, to any person obtaining a copy of |
donatien | 0:04a82df0f587 | 6 | this software and associated documentation files (the "Software"), to deal in |
donatien | 0:04a82df0f587 | 7 | the Software without restriction, including without limitation the rights to |
donatien | 0:04a82df0f587 | 8 | use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies |
donatien | 0:04a82df0f587 | 9 | of the Software, and to permit persons to whom the Software is furnished to do |
donatien | 0:04a82df0f587 | 10 | so, subject to the following conditions: |
donatien | 0:04a82df0f587 | 11 | |
donatien | 0:04a82df0f587 | 12 | The above copyright notice and this permission notice shall be included in all |
donatien | 0:04a82df0f587 | 13 | copies or substantial portions of the Software. |
donatien | 0:04a82df0f587 | 14 | |
donatien | 0:04a82df0f587 | 15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
donatien | 0:04a82df0f587 | 16 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
donatien | 0:04a82df0f587 | 17 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
donatien | 0:04a82df0f587 | 18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
donatien | 0:04a82df0f587 | 19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
donatien | 0:04a82df0f587 | 20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
donatien | 0:04a82df0f587 | 21 | SOFTWARE. |
donatien | 0:04a82df0f587 | 22 | */ |
donatien | 0:04a82df0f587 | 23 | |
donatien | 1:b221a8765b3f | 24 | #define __DEBUG__ 0 //Disabled |
donatien | 0:04a82df0f587 | 25 | #ifndef __MODULE__ |
donatien | 0:04a82df0f587 | 26 | #define __MODULE__ "NTPClient.cpp" |
donatien | 0:04a82df0f587 | 27 | #endif |
donatien | 0:04a82df0f587 | 28 | |
donatien | 0:04a82df0f587 | 29 | #include "core/fwk.h" |
donatien | 0:04a82df0f587 | 30 | |
donatien | 0:04a82df0f587 | 31 | #include "NTPClient.h" |
donatien | 0:04a82df0f587 | 32 | |
donatien | 1:b221a8765b3f | 33 | #include "UDPSocket.h" |
donatien | 1:b221a8765b3f | 34 | |
donatien | 0:04a82df0f587 | 35 | #include "mbed.h" //time() and set_time() |
donatien | 0:04a82df0f587 | 36 | |
donatien | 0:04a82df0f587 | 37 | #define NTP_PORT 123 |
donatien | 0:04a82df0f587 | 38 | #define NTP_CLIENT_PORT 0 //Random port |
donatien | 0:04a82df0f587 | 39 | #define NTP_REQUEST_TIMEOUT 15000 |
donatien | 0:04a82df0f587 | 40 | #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 | 41 | |
donatien | 0:04a82df0f587 | 42 | NTPClient::NTPClient() |
donatien | 0:04a82df0f587 | 43 | { |
donatien | 0:04a82df0f587 | 44 | |
donatien | 0:04a82df0f587 | 45 | |
donatien | 0:04a82df0f587 | 46 | } |
donatien | 0:04a82df0f587 | 47 | |
donatien | 0:04a82df0f587 | 48 | int NTPClient::setTime(const char* host, uint16_t port, uint32_t timeout) |
donatien | 0:04a82df0f587 | 49 | { |
donatien | 0:04a82df0f587 | 50 | #if __DEBUG__ >= 3 |
donatien | 0:04a82df0f587 | 51 | time_t ctTime; |
donatien | 0:04a82df0f587 | 52 | ctTime = time(NULL); |
donatien | 0:04a82df0f587 | 53 | INFO("Time is set to (UTC): %s", ctime(&ctTime)); |
donatien | 0:04a82df0f587 | 54 | #endif |
donatien | 0:04a82df0f587 | 55 | |
donatien | 1:b221a8765b3f | 56 | //Create & bind socket |
donatien | 0:04a82df0f587 | 57 | DBG("Creating socket"); |
donatien | 1:b221a8765b3f | 58 | UDPSocket sock; |
donatien | 1:b221a8765b3f | 59 | sock.bind(0); //Bind to a random port |
donatien | 0:04a82df0f587 | 60 | |
donatien | 0:04a82df0f587 | 61 | struct NTPPacket pkt; |
donatien | 0:04a82df0f587 | 62 | |
donatien | 0:04a82df0f587 | 63 | //Now ping the server and wait for response |
donatien | 0:04a82df0f587 | 64 | DBG("Ping"); |
donatien | 0:04a82df0f587 | 65 | //Prepare NTP Packet: |
donatien | 0:04a82df0f587 | 66 | pkt.li = 0; //Leap Indicator : No warning |
donatien | 0:04a82df0f587 | 67 | pkt.vn = 4; //Version Number : 4 |
donatien | 0:04a82df0f587 | 68 | pkt.mode = 3; //Client mode |
donatien | 0:04a82df0f587 | 69 | pkt.stratum = 0; //Not relevant here |
donatien | 0:04a82df0f587 | 70 | pkt.poll = 0; //Not significant as well |
donatien | 0:04a82df0f587 | 71 | pkt.precision = 0; //Neither this one is |
donatien | 0:04a82df0f587 | 72 | |
donatien | 0:04a82df0f587 | 73 | pkt.rootDelay = 0; //Or this one |
donatien | 0:04a82df0f587 | 74 | pkt.rootDispersion = 0; //Or that one |
donatien | 0:04a82df0f587 | 75 | pkt.refId = 0; //... |
donatien | 0:04a82df0f587 | 76 | |
donatien | 0:04a82df0f587 | 77 | pkt.refTm_s = 0; |
donatien | 0:04a82df0f587 | 78 | pkt.origTm_s = 0; |
donatien | 0:04a82df0f587 | 79 | pkt.rxTm_s = 0; |
donatien | 0:04a82df0f587 | 80 | pkt.txTm_s = htonl( NTP_TIMESTAMP_DELTA + time(NULL) ); //WARN: We are in LE format, network byte order is BE |
donatien | 0:04a82df0f587 | 81 | |
donatien | 0:04a82df0f587 | 82 | pkt.refTm_f = pkt.origTm_f = pkt.rxTm_f = pkt.txTm_f = 0; |
donatien | 0:04a82df0f587 | 83 | |
donatien | 0:04a82df0f587 | 84 | //Set timeout, non-blocking and wait using select |
donatien | 1:b221a8765b3f | 85 | if( sock.sendTo( (char*)&pkt, sizeof(NTPPacket), host, port, NTP_REQUEST_TIMEOUT ) < 0 ) |
donatien | 0:04a82df0f587 | 86 | { |
donatien | 0:04a82df0f587 | 87 | ERR("Could not send packet"); |
donatien | 1:b221a8765b3f | 88 | sock.close(); |
donatien | 0:04a82df0f587 | 89 | return NET_CONN; |
donatien | 0:04a82df0f587 | 90 | } |
donatien | 0:04a82df0f587 | 91 | |
donatien | 0:04a82df0f587 | 92 | //Read response |
donatien | 0:04a82df0f587 | 93 | DBG("Pong"); |
donatien | 1:b221a8765b3f | 94 | char* inHost; |
donatien | 1:b221a8765b3f | 95 | int inPort; |
donatien | 0:04a82df0f587 | 96 | do |
donatien | 0:04a82df0f587 | 97 | { |
donatien | 1:b221a8765b3f | 98 | ret = sock.receiveFrom( (char*)&pkt, sizeof(NTPPacket), &inHost, inPort); //FIXME need a DNS Resolver to actually compare the incoming address with the DNS name |
donatien | 0:04a82df0f587 | 99 | if(ret < 0) |
donatien | 0:04a82df0f587 | 100 | { |
donatien | 0:04a82df0f587 | 101 | ERR("Could not receive packet"); |
donatien | 1:b221a8765b3f | 102 | sock.close(); |
donatien | 0:04a82df0f587 | 103 | return NET_CONN; |
donatien | 0:04a82df0f587 | 104 | } |
donatien | 0:04a82df0f587 | 105 | } while( respAddr.sin_addr.s_addr != serverAddr.sin_addr.s_addr); |
donatien | 0:04a82df0f587 | 106 | |
donatien | 0:04a82df0f587 | 107 | if(ret < sizeof(NTPPacket)) //TODO: Accept chunks |
donatien | 0:04a82df0f587 | 108 | { |
donatien | 0:04a82df0f587 | 109 | ERR("Receive packet size does not match"); |
donatien | 1:b221a8765b3f | 110 | sock.close(); |
donatien | 0:04a82df0f587 | 111 | return NET_PROTOCOL; |
donatien | 0:04a82df0f587 | 112 | } |
donatien | 0:04a82df0f587 | 113 | |
donatien | 0:04a82df0f587 | 114 | if( pkt.stratum == 0) //Kiss of death message : Not good ! |
donatien | 0:04a82df0f587 | 115 | { |
donatien | 0:04a82df0f587 | 116 | ERR("Kissed to death!"); |
donatien | 1:b221a8765b3f | 117 | sock.close(); |
donatien | 0:04a82df0f587 | 118 | return NTP_PORT; |
donatien | 0:04a82df0f587 | 119 | } |
donatien | 0:04a82df0f587 | 120 | |
donatien | 0:04a82df0f587 | 121 | //Correct Endianness |
donatien | 0:04a82df0f587 | 122 | pkt.refTm_s = ntohl( pkt.refTm_s ); |
donatien | 0:04a82df0f587 | 123 | pkt.refTm_f = ntohl( pkt.refTm_f ); |
donatien | 0:04a82df0f587 | 124 | pkt.origTm_s = ntohl( pkt.origTm_s ); |
donatien | 0:04a82df0f587 | 125 | pkt.origTm_f = ntohl( pkt.origTm_f ); |
donatien | 0:04a82df0f587 | 126 | pkt.rxTm_s = ntohl( pkt.rxTm_s ); |
donatien | 0:04a82df0f587 | 127 | pkt.rxTm_f = ntohl( pkt.rxTm_f ); |
donatien | 0:04a82df0f587 | 128 | pkt.txTm_s = ntohl( pkt.txTm_s ); |
donatien | 0:04a82df0f587 | 129 | pkt.txTm_f = ntohl( pkt.txTm_f ); |
donatien | 0:04a82df0f587 | 130 | |
donatien | 0:04a82df0f587 | 131 | //Compute offset, see RFC 4330 p.13 |
donatien | 0:04a82df0f587 | 132 | uint32_t destTm_s = (NTP_TIMESTAMP_DELTA + time(NULL)); |
donatien | 0:04a82df0f587 | 133 | int64_t offset = ( (int64_t)( pkt.rxTm_s - pkt.origTm_s ) + (int64_t) ( pkt.txTm_s - destTm_s ) ) / 2; //Avoid overflow |
donatien | 0:04a82df0f587 | 134 | DBG("Sent @%ul", pkt.txTm_s); |
donatien | 0:04a82df0f587 | 135 | DBG("Offset: %ul", offset); |
donatien | 0:04a82df0f587 | 136 | //Set time accordingly |
donatien | 0:04a82df0f587 | 137 | set_time( time(NULL) + offset ); |
donatien | 0:04a82df0f587 | 138 | |
donatien | 0:04a82df0f587 | 139 | #if __DEBUG__ >= 3 |
donatien | 0:04a82df0f587 | 140 | ctTime = time(NULL); |
donatien | 0:04a82df0f587 | 141 | INFO("Time is now (UTC): %s", ctime(&ctTime)); |
donatien | 0:04a82df0f587 | 142 | #endif |
donatien | 0:04a82df0f587 | 143 | |
donatien | 1:b221a8765b3f | 144 | sock.close(); |
donatien | 0:04a82df0f587 | 145 | |
donatien | 0:04a82df0f587 | 146 | return OK; |
donatien | 0:04a82df0f587 | 147 | } |
donatien | 0:04a82df0f587 | 148 |