Darran Shepherd
/
AutoIpNetStack
Net stack with AutoIP enabled
Diff: services/ntp/NTPClient.cpp
- Revision:
- 0:ac21159e27f4
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/services/ntp/NTPClient.cpp Fri Jul 02 17:21:58 2010 +0000 @@ -0,0 +1,331 @@ + +/* +Copyright (c) 2010 Donatien Garnier (donatiengar [at] gmail [dot] com) + +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. +*/ + +#include "NTPClient.h" + +#include <stdio.h> + +//#define __DEBUG +#include "dbg/dbg.h" + +#define NTP_PORT 123 +#define NTP_CLIENT_PORT 0//50420 //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) + +#define htons( x ) ( (( x << 8 ) & 0xFF00) | (( x >> 8 ) & 0x00FF) ) +#define ntohs( x ) (htons(x)) + +#define htonl( x ) ( (( x << 24 ) & 0xFF000000) \ + | (( x << 8 ) & 0x00FF0000) \ + | (( x >> 8 ) & 0x0000FF00) \ + | (( x >> 24 ) & 0x000000FF) ) +#define ntohl( x ) (htonl(x)) + +NTPClient::NTPClient() : NetService(false), m_state(NTP_PING), m_pCbItem(NULL), m_pCbMeth(NULL), m_pCb(NULL), +m_watchdog(), m_timeout(0), m_closed(true), m_host(), m_pDnsReq(NULL), m_blockingResult(NTP_PROCESSING) +{ + setTimeout(NTP_REQUEST_TIMEOUT); + DBG("\r\nNew NTPClient %p\r\n",this); +} + +NTPClient::~NTPClient() +{ + close(); +} + +//High level setup functions +NTPResult NTPClient::setTime(const Host& host) //Blocking +{ + doSetTime(host); + return blockingProcess(); +} + +NTPResult NTPClient::setTime(const Host& host, void (*pMethod)(NTPResult)) //Non blocking +{ + setOnResult(pMethod); + doSetTime(host); + return NTP_PROCESSING; +} + +#if 0 //For doc only +template<class T> +NTPResult NTPClient::setTime(const Host& host, T* pItem, void (T::*pMethod)(NTPResult)) //Non blocking +{ + setOnResult(pItem, pMethod); + doSetTime(host); + return NTP_PROCESSING; +} +#endif + +void NTPClient::doSetTime(const Host& host) +{ + init(); + resetTimeout(); + m_host = host; + if(!m_host.getPort()) + { + m_host.setPort(NTP_PORT); + } + if(m_host.getIp().isNull()) + { + //DNS query required + m_pDnsReq = new DNSRequest(); + DBG("\r\nNTPClient : DNSRequest %p\r\n", m_pDnsReq); + m_pDnsReq->setOnReply(this, &NTPClient::onDNSReply); + m_pDnsReq->resolve(&m_host); + return; + } + open(); +} + +void NTPClient::setOnResult( void (*pMethod)(NTPResult) ) +{ + m_pCb = pMethod; +} + +void NTPClient::close() +{ + if(m_closed) + return; + m_closed = true; //Prevent recursive calling or calling on an object being destructed by someone else + m_watchdog.stop(); + m_pUDPSocket->resetOnEvent(); + m_pUDPSocket->close(); + delete m_pUDPSocket; + if( m_pDnsReq ) + { + m_pDnsReq->close(); + delete m_pDnsReq; + m_pDnsReq = NULL; + } +} + +void NTPClient::poll() //Called by NetServices +{ + if( (!m_closed) && (m_watchdog.read_ms() >= m_timeout) ) + { + onTimeout(); + } +} + +void NTPClient::init() //Create and setup socket if needed +{ + if(!m_closed) //Already opened + return; + m_state = NTP_PING; + m_pUDPSocket = new UDPSocket; + m_pUDPSocket->setOnEvent(this, &NTPClient::onUDPSocketEvent); + m_closed = false; + DBG("NTPClient: Init OK\n"); +} + +void NTPClient::open() +{ + resetTimeout(); + DBG("Opening connection\n"); + m_state = NTP_PING; + Host localhost(IpAddr(127,0,0,1), NTP_CLIENT_PORT, "localhost"); + m_pUDPSocket->bind(localhost); + set_time( 1280000000 ); //End of July 2010... just there to limit offset range + process(); +} + +#define MIN(a,b) ((a)<(b))?(a):(b) +void NTPClient::process() //Main state-machine +{ + int len; + Host host; + + switch(m_state) + { + case NTP_PING: + DBG("\r\nPing\r\n"); + //Prepare NTP Packet: + m_pkt.li = 0; //Leap Indicator : No warning + m_pkt.vn = 4; //Version Number : 4 + m_pkt.mode = 3; //Client mode + m_pkt.stratum = 0; //Not relevant here + m_pkt.poll = 0; //Not significant as well + m_pkt.precision = 0; //Neither this one is + + m_pkt.rootDelay = 0; //Or this one + m_pkt.rootDispersion = 0; //Or that one + m_pkt.refId = 0; //... + + m_pkt.refTm_s = 0; + m_pkt.origTm_s = 0; + m_pkt.rxTm_s = 0; + m_pkt.txTm_s = htonl( NTP_TIMESTAMP_DELTA + time(NULL) ); //WARN: We are in LE format, network byte order is BE + + m_pkt.refTm_f = m_pkt.origTm_f = m_pkt.rxTm_f = m_pkt.txTm_f = 0; + + //Hex Dump: + DBG("\r\nDump Tx:\r\n"); + for(int i = 0; i< sizeof(NTPPacket); i++) + { + DBG("%02x ", *((char*)&m_pkt + i)); + } + DBG("\r\n\r\n"); + + len = m_pUDPSocket->sendto( (char*)&m_pkt, sizeof(NTPPacket), &m_host ); + if(len < sizeof(NTPPacket)) + { onResult(NTP_PRTCL); close(); return; } + + m_state = NTP_PONG; + + break; + + case NTP_PONG: + DBG("\r\nPong\r\n"); + while( len = m_pUDPSocket->recvfrom( (char*)&m_pkt, sizeof(NTPPacket), &host ) ) + { + if( len <= 0 ) + break; + if( !host.getIp().isEq(m_host.getIp()) ) + continue; //Not our packet + if( len > 0 ) + break; + } + + if(len == 0) + return; //Wait for the next packet + + if(len < 0) + { onResult(NTP_PRTCL); close(); return; } + + if(len < sizeof(NTPPacket)) //TODO: Accept chunks + { onResult(NTP_PRTCL); close(); return; } + + //Hex Dump: + DBG("\r\nDump Rx:\r\n"); + for(int i = 0; i< sizeof(NTPPacket); i++) + { + DBG("%02x ", *((char*)&m_pkt + i)); + } + DBG("\r\n\r\n"); + + if( m_pkt.stratum == 0) //Kiss of death message : Not good ! + { + onResult(NTP_PRTCL); close(); return; + } + + //Correct Endianness + m_pkt.refTm_s = ntohl( m_pkt.refTm_s ); + m_pkt.refTm_f = ntohl( m_pkt.refTm_f ); + m_pkt.origTm_s = ntohl( m_pkt.origTm_s ); + m_pkt.origTm_f = ntohl( m_pkt.origTm_f ); + m_pkt.rxTm_s = ntohl( m_pkt.rxTm_s ); + m_pkt.rxTm_f = ntohl( m_pkt.rxTm_f ); + m_pkt.txTm_s = ntohl( m_pkt.txTm_s ); + m_pkt.txTm_f = ntohl( m_pkt.txTm_f ); + + //Compute offset, see RFC 4330 p.13 + uint32_t destTm_s = (NTP_TIMESTAMP_DELTA + time(NULL)); + //int32_t origTm = (int32_t) ((uint64_t) m_pkt.origTm - NTP_TIMESTAMP_DELTA); //Convert in local 32 bits timestamps + //int32_t rxTm = (int32_t) ((uint64_t) m_pkt.rxTm - NTP_TIMESTAMP_DELTA); //Convert in local 32 bits timestamps + //int32_t txTm = (int32_t) ((uint64_t) m_pkt.txTm - NTP_TIMESTAMP_DELTA); //Convert in local 32 bits timestamps + // int64_t offset = ( ( ( m_pkt.rxTm_s - m_pkt.origTm_s ) + ( m_pkt.txTm_s - destTm_s ) ) << 32 + ( ( m_pkt.rxTm_f - m_pkt.origTm_f ) + ( m_pkt.txTm_f - 0 ) ) ) / 2; + int64_t offset = ( (int64_t)( m_pkt.rxTm_s - m_pkt.origTm_s ) + (int64_t) ( m_pkt.txTm_s - destTm_s ) ) / 2; //Avoid overflow + DBG("\r\nSent @%d\r\n", m_pkt.txTm_s); + DBG("\r\nOffset: %d\r\n", offset); + //Set time accordingly + set_time( time(NULL) + (offset /*>> 32*/) ); + + onResult(NTP_OK); + close(); + + break; + } +} + +void NTPClient::setTimeout(int ms) +{ + m_timeout = ms; +} + +void NTPClient::resetTimeout() +{ + m_watchdog.reset(); + m_watchdog.start(); +} + +void NTPClient::onTimeout() //Connection has timed out +{ + close(); + onResult(NTP_TIMEOUT); +} + +void NTPClient::onDNSReply(DNSReply r) +{ + if(m_closed) + { + DBG("\r\nWARN: Discarded\r\n"); + return; + } + + if( r != DNS_FOUND ) + { + DBG("\r\nCould not resolve hostname.\r\n"); + onResult(NTP_DNS); + close(); + return; + } + DBG("\r\nDNS resolved.\r\n"); + m_pDnsReq->close(); + delete m_pDnsReq; + m_pDnsReq=NULL; + open(); +} + +void NTPClient::onUDPSocketEvent(UDPSocketEvent e) +{ + resetTimeout(); + switch(e) + { + case UDPSOCKET_READABLE: //The only event for now + resetTimeout(); + process(); + break; + } +} + +void NTPClient::onResult(NTPResult r) //Must be called by impl when the request completes +{ + if(m_pCbItem && m_pCbMeth) + (m_pCbItem->*m_pCbMeth)(r); + else if(m_pCb) + m_pCb(r); + m_blockingResult = r; //Blocking mode +} + +NTPResult NTPClient::blockingProcess() //Called in blocking mode, calls Net::poll() until return code is available +{ + m_blockingResult = NTP_PROCESSING; + do + { + Net::poll(); + } while(m_blockingResult == NTP_PROCESSING); + Net::poll(); //Necessary for cleanup + return m_blockingResult; +}