ntpclientquery.c

00001 #include <stdint.h>
00002 #include <string.h>
00003 #include <stdbool.h>
00004 
00005 #include "log.h"
00006 #include "clk.h"
00007 #include "mstimer.h"
00008 #include "clktime.h"
00009 #include "ntptimestamp.h"
00010 #include "clkutc.h"
00011 #include "clkgov.h"
00012 #include "clktm.h"
00013 #include "net.h"
00014 #include "ntp.h"
00015 #include "ntphdr.h"
00016 #include "ntpclient.h"
00017 #include "dns.h"
00018 #include "ip4.h"
00019 #include "resolve.h"
00020 #include "action.h"
00021 #include "dnslabel.h"
00022 
00023 #define ONE_BILLION 1000000000ULL
00024 #define ONE_MILLION     1000000LL
00025 
00026 char    NtpClientQueryServerName[DNS_MAX_LABEL_LENGTH+1]; 
00027 int32_t NtpClientQueryInitialInterval;                    
00028 int32_t NtpClientQueryNormalInterval;                     
00029 int32_t NtpClientQueryRetryInterval;                      
00030 
00031 bool       NtpClientQuerySendRequestsViaIp4 = false;
00032 uint32_t   NtpClientQueryServerIp4;
00033 char       NtpClientQueryServerIp6[16];
00034 
00035 static uint64_t startNtpMs = 0;
00036 static int  intervalTypeNtp = NTP_QUERY_INTERVAL_INITIAL;
00037 static bool intervalCompleteNtp()
00038 {
00039     uint32_t interval;
00040     switch(intervalTypeNtp)
00041     {
00042         case NTP_QUERY_INTERVAL_INITIAL: interval = NtpClientQueryInitialInterval; break;
00043         case NTP_QUERY_INTERVAL_NORMAL:  interval = NtpClientQueryNormalInterval;  break;
00044         case NTP_QUERY_INTERVAL_RETRY:   interval = NtpClientQueryRetryInterval;   break;
00045     }
00046     return MsTimerRelative(startNtpMs, interval * 1000);
00047 }
00048 void NtpClientQueryStartInterval(int type)
00049 {
00050     startNtpMs = MsTimerCount;
00051     intervalTypeNtp = type;
00052 }
00053 
00054 void writeRequest(char* pPacket, int* pSize)
00055 {   
00056     NtpHdrSetMode(pPacket, NTP_CLIENT);
00057     NtpHdrSetVersion     (pPacket, 3);
00058     NtpHdrSetLI          (pPacket, 0);
00059     NtpHdrSetStratum     (pPacket, 0);
00060     NtpHdrSetPoll        (pPacket, 0);
00061     NtpHdrSetPrecision   (pPacket, 0);
00062     NtpHdrSetRootDelay   (pPacket, 0);
00063     NtpHdrSetDispersion  (pPacket, 0);
00064     char* p = NtpHdrPtrRefIdentifier(pPacket);
00065     *p++ = 0;
00066     *p++ = 0;
00067     *p++ = 0;
00068     *p   = 0;
00069     NtpHdrSetRefTimeStamp(pPacket, 0);
00070     NtpHdrSetOriTimeStamp(pPacket, 0);
00071     NtpHdrSetRecTimeStamp(pPacket, 0);
00072     NtpClientQueryTime = NtpTimeStampFromClkTime(ClkTimeGet()); //Record the time to filter replies; use the costly time
00073     NtpHdrSetTraTimeStamp(pPacket, NtpClientQueryTime);
00074 
00075     *pSize = NTP_HEADER_LENGTH;
00076 }
00077 
00078 int NtpClientQueryPoll(int type, char* pPacket, int* pSize)
00079 {
00080     if (NtpClientQueryServerName[0]) //An empty name means ntp client is not enabled
00081     {
00082         if (intervalCompleteNtp()) //Wait for the time out
00083         {
00084             bool isMulticast = NtpClientQueryServerName[0] == '*';
00085             if (isMulticast || Resolve(NtpClientQueryServerName, type, &NtpClientQueryServerIp4, NtpClientQueryServerIp6))
00086             {
00087                 ClkGovIsReceivingTime = false;
00088                 NtpClientQueryStartInterval(NTP_QUERY_INTERVAL_RETRY);
00089                 writeRequest(pPacket, pSize);
00090                 
00091                 if (isMulticast) return MULTICAST_NTP;
00092                 else             return   UNICAST_NTP;
00093             }
00094         }
00095     }
00096     return DO_NOTHING;
00097 }