1 /* $NetBSD: caltontp.c,v 1.6 2020/05/25 20:47:24 christos Exp $ */ 2 3 /* 4 * caltontp - convert a date to an NTP time 5 */ 6 #include <config.h> 7 #include <sys/types.h> 8 9 #include "ntp_types.h" 10 #include "ntp_calendar.h" 11 #include "ntp_stdlib.h" 12 #include "ntp_assert.h" 13 #include "ntp_unixtime.h" 14 15 /* 16 * Juergen Perlinger, 2008-11-12 17 * Add support for full calendar calculatios. If the day-of-year is provided 18 * (that is, not zero) it will be used instead of month and day-of-month; 19 * otherwise a full turn through the calendar calculations will be taken. 20 * 21 * I know that Harlan Stenn likes to see assertions in production code, and I 22 * agree there, but it would be a tricky thing here. The algorithm is quite 23 * capable of producing sensible answers even to seemingly weird inputs: the 24 * date <any year here>-03-00, the 0.th March of the year, will be automtically 25 * treated as the last day of February, no matter whether the year is a leap 26 * year or not. So adding constraints is merely for the benefit of the callers, 27 * because the only thing we can check for consistency is our input, produced 28 * by somebody else. 29 * 30 * BTW: A total roundtrip using 'caljulian' would be a quite shaky thing: 31 * Because of the truncation of the NTP time stamp to 32 bits and the epoch 32 * unfolding around the current time done by 'caljulian' the roundtrip does 33 * *not* necessarily reproduce the input, especially if the time spec is more 34 * than 68 years off from the current time... 35 */ 36 37 uint32_t 38 caltontp( 39 const struct calendar *jt 40 ) 41 { 42 int32_t eraday; /* CE Rata Die number */ 43 vint64 ntptime;/* resulting NTP time */ 44 45 REQUIRE(jt != NULL); 46 47 REQUIRE(jt->month <= 13); /* permit month 0..13! */ 48 REQUIRE(jt->monthday <= 32); 49 REQUIRE(jt->yearday <= 366); 50 REQUIRE(jt->hour <= 24); 51 REQUIRE(jt->minute <= MINSPERHR); 52 REQUIRE(jt->second <= SECSPERMIN); 53 54 /* 55 * First convert the date to he corresponding RataDie 56 * number. If yearday is not zero, assume that it contains a 57 * useable value and avoid all calculations involving month 58 * and day-of-month. Do a full evaluation otherwise. 59 */ 60 if (jt->yearday) 61 eraday = ntpcal_year_to_ystart(jt->year) 62 + jt->yearday - 1; 63 else 64 eraday = ntpcal_date_to_rd(jt); 65 66 ntptime = ntpcal_dayjoin(eraday - DAY_NTP_STARTS, 67 ntpcal_etime_to_seconds(jt->hour, jt->minute, 68 jt->second)); 69 return ntptime.d_s.lo; 70 } 71