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udp/ntp/ntpserver.c@138:5ff0c7069300, 2019-04-07 (annotated)

Committer:
andrewboyson
Date:
Sun Apr 07 18:36:42 2019 +0000
Revision:
138:5ff0c7069300
Parent:
134:3aa1bc602b19 
Removed all __packed structs

Who changed what in which revision?

UserRevisionLine numberNew contents of line
andrewboyson 113:904b40231907 1 #include <stdint.h>
andrewboyson 134:3aa1bc602b19 2 #include <stdlib.h>
andrewboyson 113:904b40231907 3
andrewboyson 113:904b40231907 4 #include "clk.h"
andrewboyson 113:904b40231907 5 #include "clkgov.h"
andrewboyson 113:904b40231907 6 #include "clktime.h"
andrewboyson 113:904b40231907 7 #include "clkutc.h"
andrewboyson 124:6e558721ec1c 8 #include "ntptimestamp.h"
andrewboyson 113:904b40231907 9 #include "ntp.h"
andrewboyson 138:5ff0c7069300 10 #include "ntphdr.h"
andrewboyson 113:904b40231907 11 #include "action.h"
andrewboyson 113:904b40231907 12 #include "log.h"
andrewboyson 113:904b40231907 13 #include "net.h"
andrewboyson 113:904b40231907 14
andrewboyson 113:904b40231907 15 #define LI_PRIOR_NOTICE_SECONDS 10LL * 24 * 60 * 60
andrewboyson 113:904b40231907 16
andrewboyson 113:904b40231907 17 bool NtpServerEnable = false;
andrewboyson 113:904b40231907 18
andrewboyson 113:904b40231907 19 char* NtpServerName = "";
andrewboyson 113:904b40231907 20
andrewboyson 113:904b40231907 21 static int getPrecision()
andrewboyson 113:904b40231907 22 {
andrewboyson 113:904b40231907 23 /*
andrewboyson 113:904b40231907 24 The Precision field is set to reflect the maximum reading error of the local clock.
andrewboyson 113:904b40231907 25 For all practical cases it is computed as the negative of the number of significant bits
andrewboyson 113:904b40231907 26 to the right of the decimal point in the NTP timestamp format.
andrewboyson 113:904b40231907 27 While that could be CLK_TIME_ONE_SECOND_SHIFT I think that would be the resolution not the precision
andrewboyson 113:904b40231907 28 I therefore assume I can count on the clock to be good to about a microsecond or 2^-20
andrewboyson 113:904b40231907 29 */
andrewboyson 113:904b40231907 30 return -20;
andrewboyson 113:904b40231907 31 }
andrewboyson 113:904b40231907 32 static int getLi()
andrewboyson 113:904b40231907 33 {
andrewboyson 113:904b40231907 34 if (!ClkTimeIsSet() ) return 3; //Alarm condition; clock is not synchronised
andrewboyson 113:904b40231907 35 if (!ClkUtcGetNextLeapEnable()) return 0; //No warning
andrewboyson 113:904b40231907 36
andrewboyson 125:8c84daac38ab 37 clktime nowTime = ClkUtcFromTai(ClkNowTai()); //Use the less costly time this scan
andrewboyson 125:8c84daac38ab 38 clktime liPriorNotice = LI_PRIOR_NOTICE_SECONDS << CLK_TIME_ONE_SECOND_SHIFT;
andrewboyson 113:904b40231907 39
andrewboyson 113:904b40231907 40 if (nowTime > ClkUtcGetNextEpoch() - liPriorNotice)
andrewboyson 113:904b40231907 41 {
andrewboyson 113:904b40231907 42 if (ClkUtcGetNextLeapForward()) return 1; //Last minute has 61 seconds
andrewboyson 113:904b40231907 43 else return 2; //Last minute has 59 seconds
andrewboyson 113:904b40231907 44 }
andrewboyson 113:904b40231907 45 else
andrewboyson 113:904b40231907 46 {
andrewboyson 113:904b40231907 47 return 0; //No warning
andrewboyson 113:904b40231907 48 }
andrewboyson 113:904b40231907 49 }
andrewboyson 113:904b40231907 50
andrewboyson 113:904b40231907 51 static int getStratum()
andrewboyson 113:904b40231907 52 {
andrewboyson 113:904b40231907 53 if (ClkTimeIsSet()) return 1;
andrewboyson 113:904b40231907 54 else return 0;
andrewboyson 113:904b40231907 55 }
andrewboyson 113:904b40231907 56 static char* getIdent()
andrewboyson 113:904b40231907 57 {
andrewboyson 113:904b40231907 58 if (!ClkTimeIsSet() ) return "INIT";
andrewboyson 113:904b40231907 59 if (!ClkGovIsSynced()) return "LOCL";
andrewboyson 113:904b40231907 60 return NtpServerName;
andrewboyson 113:904b40231907 61 }
andrewboyson 113:904b40231907 62 static uint64_t getRefNtp()
andrewboyson 113:904b40231907 63 {
andrewboyson 124:6e558721ec1c 64 return NtpTimeStampFromClkTime(ClkRefTai());
andrewboyson 113:904b40231907 65 }
andrewboyson 138:5ff0c7069300 66 int NtpServerRequest(void (*traceback)(void), char* pPacketRx, char* pPacketTx)
andrewboyson 113:904b40231907 67 {
andrewboyson 113:904b40231907 68 if (!NtpServerEnable) return DO_NOTHING;
andrewboyson 113:904b40231907 69
andrewboyson 113:904b40231907 70 if (NtpTrace)
andrewboyson 113:904b40231907 71 {
andrewboyson 113:904b40231907 72 if (NetTraceNewLine) Log("\r\n");
andrewboyson 113:904b40231907 73 LogTimeF("NTP received request\r\n");
andrewboyson 113:904b40231907 74 if (NetTraceStack) traceback();
andrewboyson 138:5ff0c7069300 75 NtpLogHeader(pPacketRx);
andrewboyson 113:904b40231907 76 }
andrewboyson 134:3aa1bc602b19 77
andrewboyson 113:904b40231907 78 uint64_t refNtp = getRefNtp();
andrewboyson 125:8c84daac38ab 79 uint64_t nowNtp = NtpTimeStampFromClkTime(ClkTimeGet()); //use the costly time at this instant
andrewboyson 113:904b40231907 80 int stratum = getStratum();
andrewboyson 113:904b40231907 81 char* ident = getIdent();
andrewboyson 113:904b40231907 82 int li = getLi();
andrewboyson 113:904b40231907 83 int precision = getPrecision();
andrewboyson 113:904b40231907 84
andrewboyson 138:5ff0c7069300 85 NtpHdrSetMode (pPacketTx, NTP_SERVER);
andrewboyson 138:5ff0c7069300 86 NtpHdrSetVersion (pPacketTx, NtpHdrGetVersion(pPacketRx));
andrewboyson 138:5ff0c7069300 87 NtpHdrSetLI (pPacketTx, li);
andrewboyson 138:5ff0c7069300 88 NtpHdrSetStratum (pPacketTx, stratum);
andrewboyson 138:5ff0c7069300 89 NtpHdrSetPoll (pPacketTx, NtpHdrGetPoll(pPacketRx));
andrewboyson 138:5ff0c7069300 90 NtpHdrSetPrecision (pPacketTx, precision);
andrewboyson 138:5ff0c7069300 91 NtpHdrSetRootDelay (pPacketTx, 0);
andrewboyson 138:5ff0c7069300 92 NtpHdrSetDispersion (pPacketTx, 0);
andrewboyson 138:5ff0c7069300 93 char* p = NtpHdrPtrRefIdentifier(pPacketTx);
andrewboyson 138:5ff0c7069300 94 *p++ = ident[0]; //For stratum 1 (reference clock), this is a four-octet, left-justified, zero-padded ASCII string.
andrewboyson 138:5ff0c7069300 95 *p++ = ident[1];
andrewboyson 138:5ff0c7069300 96 *p++ = ident[2];
andrewboyson 138:5ff0c7069300 97 *p = ident[3];
andrewboyson 138:5ff0c7069300 98 NtpHdrSetRefTimeStamp(pPacketTx, refNtp);
andrewboyson 138:5ff0c7069300 99 NtpHdrSetOriTimeStamp(pPacketTx, NtpHdrGetTraTimeStamp(pPacketRx));
andrewboyson 138:5ff0c7069300 100 NtpHdrSetRecTimeStamp(pPacketTx, nowNtp);
andrewboyson 138:5ff0c7069300 101 NtpHdrSetTraTimeStamp(pPacketTx, nowNtp);
andrewboyson 113:904b40231907 102
andrewboyson 138:5ff0c7069300 103 if (NtpTrace) NtpLogHeader(pPacketTx);
andrewboyson 113:904b40231907 104 return UNICAST;
andrewboyson 113:904b40231907 105 }
andrewboyson 113:904b40231907 106