1 /* 2 * calyearstart - determine the NTP time at midnight of January 1 in 3 * the year of the given date. 4 */ 5 #include <config.h> 6 #include <sys/types.h> 7 8 #include "ntp_types.h" 9 #include "ntp_calendar.h" 10 #include "ntp_stdlib.h" 11 #include "ntp_assert.h" 12 13 /* 14 * Juergen Perlinger, 2010-05-02 15 * 16 * Redone in terms of the calendar functions. It's rather simple: 17 * - expand the NTP time stamp 18 * - split into days and seconds since midnight, dropping the partial day 19 * - get full number of days before year start in NTP epoch 20 * - convert to seconds, truncated to 32 bits. 21 */ 22 u_int32 23 calyearstart(u_int32 ntptime, const time_t *pivot) 24 { 25 u_int32 ndays; /* elapsed days since NTP starts */ 26 vint64 vlong; 27 ntpcal_split split; 28 29 vlong = ntpcal_ntp_to_ntp(ntptime, pivot); 30 split = ntpcal_daysplit(&vlong); 31 ndays = ntpcal_rd_to_ystart(split.hi + DAY_NTP_STARTS) 32 - DAY_NTP_STARTS; 33 34 return (u_int32)(ndays * SECSPERDAY); 35 } 36 37 /* 38 * calmonthstart - get NTP time at midnight of the first day of the 39 * current month. 40 */ 41 u_int32 42 calmonthstart(u_int32 ntptime, const time_t *pivot) 43 { 44 u_int32 ndays; /* elapsed days since NTP starts */ 45 vint64 vlong; 46 ntpcal_split split; 47 48 vlong = ntpcal_ntp_to_ntp(ntptime, pivot); 49 split = ntpcal_daysplit(&vlong); 50 ndays = ntpcal_rd_to_mstart(split.hi + DAY_NTP_STARTS) 51 - DAY_NTP_STARTS; 52 53 return (u_int32)(ndays * SECSPERDAY); 54 } 55 56 /* 57 * calweekstart - get NTP time at midnight of the last monday on or 58 * before the current date. 59 */ 60 u_int32 61 calweekstart(u_int32 ntptime, const time_t *pivot) 62 { 63 u_int32 ndays; /* elapsed days since NTP starts */ 64 vint64 vlong; 65 ntpcal_split split; 66 67 vlong = ntpcal_ntp_to_ntp(ntptime, pivot); 68 split = ntpcal_daysplit(&vlong); 69 ndays = ntpcal_weekday_le(split.hi + DAY_NTP_STARTS, CAL_MONDAY) 70 - DAY_NTP_STARTS; 71 72 return (u_int32)(ndays * SECSPERDAY); 73 } 74 75 /* 76 * caldaystart - get NTP time at midnight of the current day. 77 */ 78 u_int32 79 caldaystart(u_int32 ntptime, const time_t *pivot) 80 { 81 vint64 vlong; 82 ntpcal_split split; 83 84 vlong = ntpcal_ntp_to_ntp(ntptime, pivot); 85 split = ntpcal_daysplit(&vlong); 86 87 return ntptime - split.lo; 88 } 89