NTP Client for the mbed networking libraries
Dependents: WiFiDip-KitchenSink WiFiDip-UsbKitchenSink WiFiDipCortexSensor
Fork of NTPClient by
This is a temporary fork of NTPClient by Donatien Garnier
Diff: NTPClient.cpp
- Revision:
- 0:04a82df0f587
- Child:
- 1:b221a8765b3f
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/NTPClient.cpp Fri May 25 13:48:49 2012 +0000 @@ -0,0 +1,202 @@ +/* NTPClient.cpp */ +/* +Copyright (C) 2012 ARM Limited. + +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. +*/ + +#define __DEBUG__ 4 //Maximum verbosity +#ifndef __MODULE__ +#define __MODULE__ "NTPClient.cpp" +#endif + +#include "core/fwk.h" + +#include "NTPClient.h" + +#include "mbed.h" //time() and set_time() + +#define NTP_PORT 123 +#define NTP_CLIENT_PORT 0 //Random port +#define NTP_REQUEST_TIMEOUT 15000 +#define NTP_TIMESTAMP_DELTA 2208988800ull //Diff btw a UNIX timestamp (Starting Jan, 1st 1970) and a NTP timestamp (Starting Jan, 1st 1900) + +NTPClient::NTPClient() +{ + + +} + +int NTPClient::setTime(const char* host, uint16_t port, uint32_t timeout) +{ + struct sockaddr_in serverAddr; + + std::memset(&serverAddr, 0, sizeof(struct sockaddr_in)); + +#if __DEBUG__ >= 3 + time_t ctTime; + ctTime = time(NULL); + INFO("Time is set to (UTC): %s", ctime(&ctTime)); +#endif + + //Resolve DNS if needed + if(serverAddr.sin_addr.s_addr == 0) + { + DBG("Resolving DNS address or populate hard-coded IP address"); + struct hostent *server = socket::gethostbyname(host); + if(server == NULL) + { + return NET_NOTFOUND; //Fail + } + memcpy((char*)&serverAddr.sin_addr.s_addr, (char*)server->h_addr_list[0], server->h_length); + } + + serverAddr.sin_family = AF_INET; + serverAddr.sin_port = htons(port); + + //Now create & bind socket + DBG("Creating socket"); + int sock = socket::socket(AF_INET, SOCK_DGRAM, 0); //UDP socket + if (sock < 0) + { + ERR("Could not create socket"); + return NET_OOM; + } + DBG("Handle is %d",sock); + + //Create local address + struct sockaddr_in localhostAddr; + + std::memset(&localhostAddr, 0, sizeof(struct sockaddr_in)); + + localhostAddr.sin_family = AF_INET; + localhostAddr.sin_port = htons(NTP_CLIENT_PORT); //Random port + localhostAddr.sin_addr.s_addr = htonl(INADDR_ANY); //Any local address + + if ( socket::bind( sock, (struct sockaddr*)&localhostAddr, sizeof(localhostAddr)) < 0 ) //Listen on local port + { + ERR("Could not bind socket"); + socket::close(sock); + return NET_OOM; + } + + 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; + + //Set timeout, non-blocking and wait using select + if( socket::sendto( sock, (void*)&pkt, sizeof(NTPPacket), 0, (struct sockaddr*)&serverAddr, sizeof(serverAddr) ) < 0 ) + { + ERR("Could not send packet"); + socket::close(sock); + return NET_CONN; + } + + //Wait for socket to be readable + //Creating FS set + fd_set socksSet; + FD_ZERO(&socksSet); + FD_SET(sock, &socksSet); + struct timeval t_val; + t_val.tv_sec = timeout / 1000; + t_val.tv_usec = (timeout - (t_val.tv_sec * 1000)) * 1000; + int ret = socket::select(FD_SETSIZE, &socksSet, NULL, NULL, &t_val); + if(ret <= 0 || !FD_ISSET(sock, &socksSet)) + { + ERR("Timeout while waiting for answer"); + socket::close(sock); + return NET_TIMEOUT; //Timeout + } + + //Read response + DBG("Pong"); + struct sockaddr_in respAddr; + socklen_t respAddrLen = sizeof(respAddr); + do + { + ret = socket::recvfrom( sock, (void*)&pkt, sizeof(NTPPacket), 0, (struct sockaddr*)&respAddr, &respAddrLen); + if(ret < 0) + { + ERR("Could not receive packet"); + socket::close(sock); + return NET_CONN; + } + } while( respAddr.sin_addr.s_addr != serverAddr.sin_addr.s_addr); + + if(ret < sizeof(NTPPacket)) //TODO: Accept chunks + { + ERR("Receive packet size does not match"); + socket::close(sock); + return NET_PROTOCOL; + } + + if( pkt.stratum == 0) //Kiss of death message : Not good ! + { + ERR("Kissed to death!"); + socket::close(sock); + return NTP_PORT; + } + + //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: %ul", offset); + //Set time accordingly + set_time( time(NULL) + offset ); + +#if __DEBUG__ >= 3 + ctTime = time(NULL); + INFO("Time is now (UTC): %s", ctime(&ctTime)); +#endif + + socket::close(sock); + + return OK; +} +