1 /* $NetBSD: clock_subr.c,v 1.25 2014/11/17 10:55:42 joerg Exp $ */ 2 3 /* 4 * Copyright (c) 1988 University of Utah. 5 * Copyright (c) 1982, 1990, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * the Systems Programming Group of the University of Utah Computer 10 * Science Department. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: Utah $Hdr: clock.c 1.18 91/01/21$ 37 * 38 * @(#)clock.c 8.2 (Berkeley) 1/12/94 39 */ 40 41 /* 42 * Generic routines to convert between a POSIX date 43 * (seconds since 1/1/1970) and yr/mo/day/hr/min/sec 44 * Derived from arch/hp300/hp300/clock.c 45 */ 46 47 #if HAVE_NBTOOL_CONFIG_H 48 #include "nbtool_config.h" 49 #endif /* HAVE_NBTOOL_CONFIG_H */ 50 51 #ifdef _KERNEL 52 #include <sys/cdefs.h> 53 __KERNEL_RCSID(0, "$NetBSD: clock_subr.c,v 1.25 2014/11/17 10:55:42 joerg Exp $"); 54 55 #include <sys/param.h> 56 #include <sys/systm.h> 57 #include <sys/errno.h> 58 #else /* ! _KERNEL */ 59 #include <string.h> 60 #include <time.h> 61 #include <errno.h> 62 #endif /* ! _KERNEL */ 63 64 #include "../sys/clock.h" 65 #include <dev/clock_subr.h> 66 67 #define FEBRUARY 2 68 69 /* for easier alignment: 70 * time from the epoch to 2000 (there were 7 leap years): */ 71 #define DAYSTO2000 (365*30+7) 72 73 /* 4 year intervals include 1 leap year */ 74 #define DAYS4YEARS (365*4+1) 75 76 /* 100 year intervals include 24 leap years */ 77 #define DAYS100YEARS (365*100+24) 78 79 /* 400 year intervals include 97 leap years */ 80 #define DAYS400YEARS (365*400+97) 81 82 time_t 83 clock_ymdhms_to_secs(struct clock_ymdhms *dt) 84 { 85 uint64_t secs, i, year, days; 86 87 year = dt->dt_year; 88 89 /* 90 * Compute days since start of time 91 * First from years, then from months. 92 */ 93 if (year < POSIX_BASE_YEAR) 94 return -1; 95 days = 0; 96 if (is_leap_year(year) && dt->dt_mon > FEBRUARY) 97 days++; 98 99 if (year < 2000) { 100 /* simple way for early years */ 101 for (i = POSIX_BASE_YEAR; i < year; i++) 102 days += days_per_year(i); 103 } else { 104 /* years are properly aligned */ 105 days += DAYSTO2000; 106 year -= 2000; 107 108 i = year / 400; 109 days += i * DAYS400YEARS; 110 year -= i * 400; 111 112 i = year / 100; 113 days += i * DAYS100YEARS; 114 year -= i * 100; 115 116 i = year / 4; 117 days += i * DAYS4YEARS; 118 year -= i * 4; 119 120 for (i = dt->dt_year-year; i < dt->dt_year; i++) 121 days += days_per_year(i); 122 } 123 124 125 /* Months */ 126 for (i = 1; i < dt->dt_mon; i++) 127 days += days_in_month(i); 128 days += (dt->dt_day - 1); 129 130 /* Add hours, minutes, seconds. */ 131 secs = (((uint64_t)days 132 * 24 + dt->dt_hour) 133 * 60 + dt->dt_min) 134 * 60 + dt->dt_sec; 135 136 if ((time_t)secs < 0 || secs > __type_max(time_t)) 137 return -1; 138 return secs; 139 } 140 141 int 142 clock_secs_to_ymdhms(time_t secs, struct clock_ymdhms *dt) 143 { 144 int leap; 145 uint64_t i; 146 time_t days; 147 time_t rsec; /* remainder seconds */ 148 149 if (secs < 0) 150 return EINVAL; 151 152 days = secs / SECS_PER_DAY; 153 rsec = secs % SECS_PER_DAY; 154 155 /* Day of week (Note: 1/1/1970 was a Thursday) */ 156 dt->dt_wday = (days + 4) % 7; 157 158 if (days >= DAYSTO2000) { 159 days -= DAYSTO2000; 160 dt->dt_year = 2000; 161 162 i = days / DAYS400YEARS; 163 days -= i*DAYS400YEARS; 164 dt->dt_year += i*400; 165 166 i = days / DAYS100YEARS; 167 days -= i*DAYS100YEARS; 168 dt->dt_year += i*100; 169 170 i = days / DAYS4YEARS; 171 days -= i*DAYS4YEARS; 172 dt->dt_year += i*4; 173 174 for (i = dt->dt_year; days >= days_per_year(i); i++) 175 days -= days_per_year(i); 176 dt->dt_year = i; 177 } else { 178 /* Subtract out whole years, counting them in i. */ 179 for (i = POSIX_BASE_YEAR; days >= days_per_year(i); i++) 180 days -= days_per_year(i); 181 dt->dt_year = i; 182 } 183 184 /* Subtract out whole months, counting them in i. */ 185 for (leap = 0, i = 1; days >= days_in_month(i)+leap; i++) { 186 days -= days_in_month(i)+leap; 187 if (i == 1 && is_leap_year(dt->dt_year)) 188 leap = 1; 189 else 190 leap = 0; 191 } 192 dt->dt_mon = i; 193 194 /* Days are what is left over (+1) from all that. */ 195 dt->dt_day = days + 1; 196 197 /* Hours, minutes, seconds are easy */ 198 dt->dt_hour = rsec / 3600; 199 rsec = rsec % 3600; 200 dt->dt_min = rsec / 60; 201 rsec = rsec % 60; 202 dt->dt_sec = rsec; 203 204 return 0; 205 } 206