1 /*- 2 * Copyright (c) 1988 University of Utah. 3 * Copyright (c) 1982, 1990, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * from: Utah $Hdr: clock.c 1.18 91/01/21$ 35 * from: @(#)clock.c 8.2 (Berkeley) 1/12/94 36 * from: NetBSD: clock_subr.c,v 1.6 2001/07/07 17:04:02 thorpej Exp 37 * and 38 * from: src/sys/i386/isa/clock.c,v 1.176 2001/09/04 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kernel.h> 47 #include <sys/bus.h> 48 #include <sys/clock.h> 49 #include <sys/limits.h> 50 #include <sys/sysctl.h> 51 #include <sys/timetc.h> 52 53 int tz_minuteswest; 54 int tz_dsttime; 55 56 /* 57 * The adjkerntz and wall_cmos_clock sysctls are in the "machdep" sysctl 58 * namespace because they were misplaced there originally. 59 */ 60 static int adjkerntz; 61 static int 62 sysctl_machdep_adjkerntz(SYSCTL_HANDLER_ARGS) 63 { 64 int error; 65 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req); 66 if (!error && req->newptr) 67 resettodr(); 68 return (error); 69 } 70 SYSCTL_PROC(_machdep, OID_AUTO, adjkerntz, CTLTYPE_INT | CTLFLAG_RW | 71 CTLFLAG_MPSAFE, &adjkerntz, 0, sysctl_machdep_adjkerntz, "I", 72 "Local offset from UTC in seconds"); 73 74 static int ct_debug; 75 SYSCTL_INT(_debug, OID_AUTO, clocktime, CTLFLAG_RW, 76 &ct_debug, 0, "Enable printing of clocktime debugging"); 77 78 static int wall_cmos_clock; 79 SYSCTL_INT(_machdep, OID_AUTO, wall_cmos_clock, CTLFLAG_RW, 80 &wall_cmos_clock, 0, "Enables application of machdep.adjkerntz"); 81 82 /*--------------------------------------------------------------------* 83 * Generic routines to convert between a POSIX date 84 * (seconds since 1/1/1970) and yr/mo/day/hr/min/sec 85 * Derived from NetBSD arch/hp300/hp300/clock.c 86 */ 87 88 89 #define FEBRUARY 2 90 #define days_in_year(y) (leapyear(y) ? 366 : 365) 91 #define days_in_month(y, m) \ 92 (month_days[(m) - 1] + (m == FEBRUARY ? leapyear(y) : 0)) 93 /* Day of week. Days are counted from 1/1/1970, which was a Thursday */ 94 #define day_of_week(days) (((days) + 4) % 7) 95 96 static const int month_days[12] = { 97 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 98 }; 99 100 101 /* 102 * This inline avoids some unnecessary modulo operations 103 * as compared with the usual macro: 104 * ( ((year % 4) == 0 && 105 * (year % 100) != 0) || 106 * ((year % 400) == 0) ) 107 * It is otherwise equivalent. 108 */ 109 static int 110 leapyear(int year) 111 { 112 int rv = 0; 113 114 if ((year & 3) == 0) { 115 rv = 1; 116 if ((year % 100) == 0) { 117 rv = 0; 118 if ((year % 400) == 0) 119 rv = 1; 120 } 121 } 122 return (rv); 123 } 124 125 static void 126 print_ct(struct clocktime *ct) 127 { 128 printf("[%04d-%02d-%02d %02d:%02d:%02d]", 129 ct->year, ct->mon, ct->day, 130 ct->hour, ct->min, ct->sec); 131 } 132 133 int 134 clock_ct_to_ts(struct clocktime *ct, struct timespec *ts) 135 { 136 int i, year, days; 137 138 year = ct->year; 139 140 if (ct_debug) { 141 printf("ct_to_ts("); 142 print_ct(ct); 143 printf(")"); 144 } 145 146 /* Sanity checks. */ 147 if (ct->mon < 1 || ct->mon > 12 || ct->day < 1 || 148 ct->day > days_in_month(year, ct->mon) || 149 ct->hour > 23 || ct->min > 59 || ct->sec > 59 || 150 (sizeof(time_t) == 4 && year > 2037)) { /* time_t overflow */ 151 if (ct_debug) 152 printf(" = EINVAL\n"); 153 return (EINVAL); 154 } 155 156 /* 157 * Compute days since start of time 158 * First from years, then from months. 159 */ 160 days = 0; 161 for (i = POSIX_BASE_YEAR; i < year; i++) 162 days += days_in_year(i); 163 164 /* Months */ 165 for (i = 1; i < ct->mon; i++) 166 days += days_in_month(year, i); 167 days += (ct->day - 1); 168 169 ts->tv_sec = (((time_t)days * 24 + ct->hour) * 60 + ct->min) * 60 + 170 ct->sec; 171 ts->tv_nsec = ct->nsec; 172 173 if (ct_debug) 174 printf(" = %ld.%09ld\n", (long)ts->tv_sec, (long)ts->tv_nsec); 175 return (0); 176 } 177 178 void 179 clock_ts_to_ct(struct timespec *ts, struct clocktime *ct) 180 { 181 int i, year, days; 182 time_t rsec; /* remainder seconds */ 183 time_t secs; 184 185 secs = ts->tv_sec; 186 days = secs / SECDAY; 187 rsec = secs % SECDAY; 188 189 ct->dow = day_of_week(days); 190 191 /* Subtract out whole years, counting them in i. */ 192 for (year = POSIX_BASE_YEAR; days >= days_in_year(year); year++) 193 days -= days_in_year(year); 194 ct->year = year; 195 196 /* Subtract out whole months, counting them in i. */ 197 for (i = 1; days >= days_in_month(year, i); i++) 198 days -= days_in_month(year, i); 199 ct->mon = i; 200 201 /* Days are what is left over (+1) from all that. */ 202 ct->day = days + 1; 203 204 /* Hours, minutes, seconds are easy */ 205 ct->hour = rsec / 3600; 206 rsec = rsec % 3600; 207 ct->min = rsec / 60; 208 rsec = rsec % 60; 209 ct->sec = rsec; 210 ct->nsec = ts->tv_nsec; 211 if (ct_debug) { 212 printf("ts_to_ct(%ld.%09ld) = ", 213 (long)ts->tv_sec, (long)ts->tv_nsec); 214 print_ct(ct); 215 printf("\n"); 216 } 217 } 218 219 int 220 utc_offset(void) 221 { 222 223 return (tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0)); 224 } 225