| 1 | /* $NetBSD: clock_subr.c,v 1.27 2016/08/15 15:51:39 jakllsch 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 1.27 2016/08/15 15:51:39 jakllsch 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 2001 (there were 8 leap years): */ |
| 71 | #define DAYSTO2001 (365*31+8) |
| 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 < 2001) { |
| 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 += DAYSTO2001; |
| 106 | year -= 2001; |
| 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 >= DAYSTO2001) { |
| 159 | days -= DAYSTO2001; |
| 160 | dt->dt_year = 2001; |
| 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 / SECS_PER_HOUR; |
| 199 | rsec = rsec % SECS_PER_HOUR; |
| 200 | dt->dt_min = rsec / SECS_PER_MINUTE; |
| 201 | rsec = rsec % SECS_PER_MINUTE; |
| 202 | dt->dt_sec = rsec; |
| 203 | |
| 204 | return 0; |
| 205 | } |
| 206 | |