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udp/ntp/ntpserver.c@123:44fea08759af, 2019-02-21 (annotated)

Committer:
andrewboyson
Date:
Thu Feb 21 12:53:06 2019 +0000
Revision:
123:44fea08759af
Parent:
113:904b40231907
Child:
124:6e558721ec1c
Updated clock library

Who changed what in which revision?

UserRevisionLine numberNew contents of line
andrewboyson 113:904b40231907 1 #include <stdint.h>
andrewboyson 113:904b40231907 2
andrewboyson 113:904b40231907 3 #include "clk.h"
andrewboyson 113:904b40231907 4 #include "clkgov.h"
andrewboyson 113:904b40231907 5 #include "clktime.h"
andrewboyson 113:904b40231907 6 #include "clkutc.h"
andrewboyson 113:904b40231907 7 #include "clkntp.h"
andrewboyson 113:904b40231907 8 #include "clkutc.h"
andrewboyson 113:904b40231907 9 #include "ntp.h"
andrewboyson 113:904b40231907 10 #include "action.h"
andrewboyson 113:904b40231907 11 #include "log.h"
andrewboyson 113:904b40231907 12 #include "net.h"
andrewboyson 113:904b40231907 13
andrewboyson 113:904b40231907 14 #define LI_PRIOR_NOTICE_SECONDS 10LL * 24 * 60 * 60
andrewboyson 113:904b40231907 15
andrewboyson 113:904b40231907 16 bool NtpServerEnable = false;
andrewboyson 113:904b40231907 17
andrewboyson 113:904b40231907 18 char* NtpServerName = "";
andrewboyson 113:904b40231907 19
andrewboyson 113:904b40231907 20 static int getPrecision()
andrewboyson 113:904b40231907 21 {
andrewboyson 113:904b40231907 22 /*
andrewboyson 113:904b40231907 23 The Precision field is set to reflect the maximum reading error of the local clock.
andrewboyson 113:904b40231907 24 For all practical cases it is computed as the negative of the number of significant bits
andrewboyson 113:904b40231907 25 to the right of the decimal point in the NTP timestamp format.
andrewboyson 113:904b40231907 26 While that could be CLK_TIME_ONE_SECOND_SHIFT I think that would be the resolution not the precision
andrewboyson 113:904b40231907 27 I therefore assume I can count on the clock to be good to about a microsecond or 2^-20
andrewboyson 113:904b40231907 28 */
andrewboyson 113:904b40231907 29 return -20;
andrewboyson 113:904b40231907 30 }
andrewboyson 113:904b40231907 31 static int getLi()
andrewboyson 113:904b40231907 32 {
andrewboyson 113:904b40231907 33 if (!ClkTimeIsSet() ) return 3; //Alarm condition; clock is not synchronised
andrewboyson 113:904b40231907 34 if (!ClkUtcGetNextLeapEnable()) return 0; //No warning
andrewboyson 113:904b40231907 35
andrewboyson 123:44fea08759af 36 int64_t nowTime = ClkUtcFromTai(ClkNowTai());
andrewboyson 113:904b40231907 37 int64_t liPriorNotice = LI_PRIOR_NOTICE_SECONDS << CLK_TIME_ONE_SECOND_SHIFT;
andrewboyson 113:904b40231907 38
andrewboyson 113:904b40231907 39 if (nowTime > ClkUtcGetNextEpoch() - liPriorNotice)
andrewboyson 113:904b40231907 40 {
andrewboyson 113:904b40231907 41 if (ClkUtcGetNextLeapForward()) return 1; //Last minute has 61 seconds
andrewboyson 113:904b40231907 42 else return 2; //Last minute has 59 seconds
andrewboyson 113:904b40231907 43 }
andrewboyson 113:904b40231907 44 else
andrewboyson 113:904b40231907 45 {
andrewboyson 113:904b40231907 46 return 0; //No warning
andrewboyson 113:904b40231907 47 }
andrewboyson 113:904b40231907 48 }
andrewboyson 113:904b40231907 49
andrewboyson 113:904b40231907 50 static int getStratum()
andrewboyson 113:904b40231907 51 {
andrewboyson 113:904b40231907 52 if (ClkTimeIsSet()) return 1;
andrewboyson 113:904b40231907 53 else return 0;
andrewboyson 113:904b40231907 54 }
andrewboyson 113:904b40231907 55 static char* getIdent()
andrewboyson 113:904b40231907 56 {
andrewboyson 113:904b40231907 57 if (!ClkTimeIsSet() ) return "INIT";
andrewboyson 113:904b40231907 58 if (!ClkGovIsSynced()) return "LOCL";
andrewboyson 113:904b40231907 59 return NtpServerName;
andrewboyson 113:904b40231907 60 }
andrewboyson 113:904b40231907 61 static uint64_t getRefNtp()
andrewboyson 113:904b40231907 62 {
andrewboyson 123:44fea08759af 63 return ClkTimeToNtpTimeStamp(ClkRefTai());
andrewboyson 113:904b40231907 64 }
andrewboyson 113:904b40231907 65 int NtpServerRequest(void (*traceback)(void), struct NtpHeader* pHeaderRx, struct NtpHeader* pHeaderTx)
andrewboyson 113:904b40231907 66 {
andrewboyson 113:904b40231907 67 if (!NtpServerEnable) return DO_NOTHING;
andrewboyson 113:904b40231907 68
andrewboyson 113:904b40231907 69 if (NtpTrace)
andrewboyson 113:904b40231907 70 {
andrewboyson 113:904b40231907 71 if (NetTraceNewLine) Log("\r\n");
andrewboyson 113:904b40231907 72 LogTimeF("NTP received request\r\n");
andrewboyson 113:904b40231907 73 if (NetTraceStack) traceback();
andrewboyson 113:904b40231907 74 NtpLogHeader(pHeaderRx);
andrewboyson 113:904b40231907 75 }
andrewboyson 113:904b40231907 76
andrewboyson 113:904b40231907 77 uint64_t refNtp = getRefNtp();
andrewboyson 113:904b40231907 78 uint64_t nowNtp = ClkTimeToNtpTimeStamp(ClkTimeGet());
andrewboyson 113:904b40231907 79 int stratum = getStratum();
andrewboyson 113:904b40231907 80 char* ident = getIdent();
andrewboyson 113:904b40231907 81 int li = getLi();
andrewboyson 113:904b40231907 82 int precision = getPrecision();
andrewboyson 113:904b40231907 83
andrewboyson 113:904b40231907 84 pHeaderTx->Mode = NTP_SERVER;
andrewboyson 113:904b40231907 85 pHeaderTx->VN = pHeaderRx->VN;
andrewboyson 113:904b40231907 86 pHeaderTx->LI = li;
andrewboyson 113:904b40231907 87 pHeaderTx->Stratum = stratum;
andrewboyson 113:904b40231907 88 pHeaderTx->Poll = pHeaderRx->Poll;
andrewboyson 113:904b40231907 89 pHeaderTx->Precision = precision;
andrewboyson 113:904b40231907 90 pHeaderTx->RootDelay = 0;
andrewboyson 113:904b40231907 91 pHeaderTx->Dispersion = 0;
andrewboyson 113:904b40231907 92 pHeaderTx->RefIdentifier[0] = ident[0]; //For stratum 1 (reference clock), this is a four-octet, left-justified, zero-padded ASCII string.
andrewboyson 113:904b40231907 93 pHeaderTx->RefIdentifier[1] = ident[1];
andrewboyson 113:904b40231907 94 pHeaderTx->RefIdentifier[2] = ident[2];
andrewboyson 113:904b40231907 95 pHeaderTx->RefIdentifier[3] = ident[3];
andrewboyson 113:904b40231907 96 pHeaderTx->RefTimeStamp = NetToHost64(refNtp);
andrewboyson 113:904b40231907 97 pHeaderTx->OriTimeStamp = pHeaderRx->TraTimeStamp;
andrewboyson 113:904b40231907 98 pHeaderTx->RecTimeStamp = NetToHost64(nowNtp);
andrewboyson 113:904b40231907 99 pHeaderTx->TraTimeStamp = NetToHost64(nowNtp);
andrewboyson 113:904b40231907 100
andrewboyson 113:904b40231907 101 if (NtpTrace) NtpLogHeader(pHeaderTx);
andrewboyson 113:904b40231907 102 return UNICAST;
andrewboyson 113:904b40231907 103 }
andrewboyson 113:904b40231907 104