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 * 4. 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: stable/11/sys/kern/subr_clock.c 331722 2018-03-29 02:50:57Z eadler $"); 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 53int tz_minuteswest; 54int 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 */ 60static int adjkerntz; 61static int 62sysctl_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} 70SYSCTL_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 74static int ct_debug; 75SYSCTL_INT(_debug, OID_AUTO, clocktime, CTLFLAG_RWTUN, 76 &ct_debug, 0, "Enable printing of clocktime debugging"); 77 78static int wall_cmos_clock; 79SYSCTL_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 96static const int month_days[12] = { 97 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 98}; 99 100/* 101 * Optimization: using a precomputed count of days between POSIX_BASE_YEAR and 102 * some recent year avoids lots of unnecessary loop iterations in conversion. 103 * recent_base_days is the number of days before the start of recent_base_year. 104 */ 105static const int recent_base_year = 2017; 106static const int recent_base_days = 17167; 107 108/* 109 * Table to 'calculate' pow(10, 9 - nsdigits) via lookup of nsdigits. 110 * Before doing the lookup, the code asserts 0 <= nsdigits <= 9. 111 */ 112static u_int nsdivisors[] = { 113 1000000000, 100000000, 10000000, 1000000, 100000, 10000, 1000, 100, 10, 1 114}; 115 116/* 117 * This inline avoids some unnecessary modulo operations 118 * as compared with the usual macro: 119 * ( ((year % 4) == 0 && 120 * (year % 100) != 0) || 121 * ((year % 400) == 0) ) 122 * It is otherwise equivalent. 123 */ 124static int 125leapyear(int year) 126{ 127 int rv = 0; 128 129 if ((year & 3) == 0) { 130 rv = 1; 131 if ((year % 100) == 0) { 132 rv = 0; 133 if ((year % 400) == 0) 134 rv = 1; 135 } 136 } 137 return (rv); 138} 139 140int 141clock_ct_to_ts(const struct clocktime *ct, struct timespec *ts) 142{ 143 int i, year, days; 144 145 if (ct_debug) { 146 printf("ct_to_ts(["); 147 clock_print_ct(ct, 9); 148 printf("])"); 149 } 150 151 /* 152 * Many realtime clocks store the year as 2-digit BCD; pivot on 70 to 153 * determine century. Some clocks have a "century bit" and drivers do 154 * year += 100, so interpret values between 70-199 as relative to 1900. 155 */ 156 year = ct->year; 157 if (year < 70) 158 year += 2000; 159 else if (year < 200) 160 year += 1900; 161 162 /* Sanity checks. */ 163 if (ct->mon < 1 || ct->mon > 12 || ct->day < 1 || 164 ct->day > days_in_month(year, ct->mon) || 165 ct->hour > 23 || ct->min > 59 || ct->sec > 59 || year < 1970 || 166 (sizeof(time_t) == 4 && year > 2037)) { /* time_t overflow */ 167 if (ct_debug) 168 printf(" = EINVAL\n"); 169 return (EINVAL); 170 } 171 172 /* 173 * Compute days since start of time 174 * First from years, then from months. 175 */ 176 if (year >= recent_base_year) { 177 i = recent_base_year; 178 days = recent_base_days; 179 } else { 180 i = POSIX_BASE_YEAR; 181 days = 0; 182 } 183 for (; i < year; i++) 184 days += days_in_year(i); 185 186 /* Months */ 187 for (i = 1; i < ct->mon; i++) 188 days += days_in_month(year, i); 189 days += (ct->day - 1); 190 191 ts->tv_sec = (((time_t)days * 24 + ct->hour) * 60 + ct->min) * 60 + 192 ct->sec; 193 ts->tv_nsec = ct->nsec; 194 195 if (ct_debug) 196 printf(" = %jd.%09ld\n", (intmax_t)ts->tv_sec, ts->tv_nsec); 197 return (0); 198} 199 200int 201clock_bcd_to_ts(const struct bcd_clocktime *bct, struct timespec *ts, bool ampm) 202{ 203 struct clocktime ct; 204 int bcent, byear; 205 206 /* 207 * Year may come in as 2-digit or 4-digit BCD. Split the value into 208 * separate BCD century and year values for validation and conversion. 209 */ 210 bcent = bct->year >> 8; 211 byear = bct->year & 0xff; 212 213 /* 214 * Ensure that all values are valid BCD numbers, to avoid assertions in 215 * the BCD-to-binary conversion routines. clock_ct_to_ts() will further 216 * validate the field ranges (such as 0 <= min <= 59) during conversion. 217 */ 218 if (!validbcd(bcent) || !validbcd(byear) || !validbcd(bct->mon) || 219 !validbcd(bct->day) || !validbcd(bct->hour) || 220 !validbcd(bct->min) || !validbcd(bct->sec)) { 221 if (ct_debug) 222 printf("clock_bcd_to_ts: bad BCD: " 223 "[%04x-%02x-%02x %02x:%02x:%02x]\n", 224 bct->year, bct->mon, bct->day, 225 bct->hour, bct->min, bct->sec); 226 return (EINVAL); 227 } 228 229 ct.year = FROMBCD(byear) + FROMBCD(bcent) * 100; 230 ct.mon = FROMBCD(bct->mon); 231 ct.day = FROMBCD(bct->day); 232 ct.hour = FROMBCD(bct->hour); 233 ct.min = FROMBCD(bct->min); 234 ct.sec = FROMBCD(bct->sec); 235 ct.dow = bct->dow; 236 ct.nsec = bct->nsec; 237 238 /* If asked to handle am/pm, convert from 12hr+pmflag to 24hr. */ 239 if (ampm) { 240 if (ct.hour == 12) 241 ct.hour = 0; 242 if (bct->ispm) 243 ct.hour += 12; 244 } 245 246 return (clock_ct_to_ts(&ct, ts)); 247} 248 249void 250clock_ts_to_ct(const struct timespec *ts, struct clocktime *ct) 251{ 252 int i, year, days; 253 time_t rsec; /* remainder seconds */ 254 time_t secs; 255 256 secs = ts->tv_sec; 257 days = secs / SECDAY; 258 rsec = secs % SECDAY; 259 260 ct->dow = day_of_week(days); 261 262 /* Subtract out whole years. */ 263 if (days >= recent_base_days) { 264 year = recent_base_year; 265 days -= recent_base_days; 266 } else { 267 year = POSIX_BASE_YEAR; 268 } 269 for (; days >= days_in_year(year); year++) 270 days -= days_in_year(year); 271 ct->year = year; 272 273 /* Subtract out whole months, counting them in i. */ 274 for (i = 1; days >= days_in_month(year, i); i++) 275 days -= days_in_month(year, i); 276 ct->mon = i; 277 278 /* Days are what is left over (+1) from all that. */ 279 ct->day = days + 1; 280 281 /* Hours, minutes, seconds are easy */ 282 ct->hour = rsec / 3600; 283 rsec = rsec % 3600; 284 ct->min = rsec / 60; 285 rsec = rsec % 60; 286 ct->sec = rsec; 287 ct->nsec = ts->tv_nsec; 288 if (ct_debug) { 289 printf("ts_to_ct(%jd.%09ld) = [", 290 (intmax_t)ts->tv_sec, ts->tv_nsec); 291 clock_print_ct(ct, 9); 292 printf("]\n"); 293 } 294} 295 296void 297clock_ts_to_bcd(const struct timespec *ts, struct bcd_clocktime *bct, bool ampm) 298{ 299 struct clocktime ct; 300 301 clock_ts_to_ct(ts, &ct); 302 303 /* If asked to handle am/pm, convert from 24hr to 12hr+pmflag. */ 304 bct->ispm = false; 305 if (ampm) { 306 if (ct.hour >= 12) { 307 ct.hour -= 12; 308 bct->ispm = true; 309 } 310 if (ct.hour == 0) 311 ct.hour = 12; 312 } 313 314 bct->year = TOBCD(ct.year % 100) | (TOBCD(ct.year / 100) << 8); 315 bct->mon = TOBCD(ct.mon); 316 bct->day = TOBCD(ct.day); 317 bct->hour = TOBCD(ct.hour); 318 bct->min = TOBCD(ct.min); 319 bct->sec = TOBCD(ct.sec); 320 bct->dow = ct.dow; 321 bct->nsec = ct.nsec; 322} 323 324void 325clock_print_bcd(const struct bcd_clocktime *bct, int nsdigits) 326{ 327 328 KASSERT(nsdigits >= 0 && nsdigits <= 9, ("bad nsdigits %d", nsdigits)); 329 330 if (nsdigits > 0) { 331 printf("%4.4x-%2.2x-%2.2x %2.2x:%2.2x:%2.2x.%*.*ld", 332 bct->year, bct->mon, bct->day, 333 bct->hour, bct->min, bct->sec, 334 nsdigits, nsdigits, bct->nsec / nsdivisors[nsdigits]); 335 } else { 336 printf("%4.4x-%2.2x-%2.2x %2.2x:%2.2x:%2.2x", 337 bct->year, bct->mon, bct->day, 338 bct->hour, bct->min, bct->sec); 339 } 340} 341 342void 343clock_print_ct(const struct clocktime *ct, int nsdigits) 344{ 345 346 KASSERT(nsdigits >= 0 && nsdigits <= 9, ("bad nsdigits %d", nsdigits)); 347 348 if (nsdigits > 0) { 349 printf("%04d-%02d-%02d %02d:%02d:%02d.%*.*ld", 350 ct->year, ct->mon, ct->day, 351 ct->hour, ct->min, ct->sec, 352 nsdigits, nsdigits, ct->nsec / nsdivisors[nsdigits]); 353 } else { 354 printf("%04d-%02d-%02d %02d:%02d:%02d", 355 ct->year, ct->mon, ct->day, 356 ct->hour, ct->min, ct->sec); 357 } 358} 359 360void 361clock_print_ts(const struct timespec *ts, int nsdigits) 362{ 363 struct clocktime ct; 364 365 clock_ts_to_ct(ts, &ct); 366 clock_print_ct(&ct, nsdigits); 367} 368 369int 370utc_offset(void) 371{ 372 373 return (tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0)); 374} 375