1171568Sscottl/* 2211095Sdes * Copyright (c) 1987, 1989 Regents of the University of California. 3171568Sscottl * All rights reserved. 4171568Sscottl * 5171568Sscottl * This code is derived from software contributed to Berkeley by 6171568Sscottl * Arthur David Olson of the National Cancer Institute. 7171568Sscottl * 8171568Sscottl * Redistribution and use in source and binary forms, with or without 9171568Sscottl * modification, are permitted provided that the following conditions 10171568Sscottl * are met: 11171568Sscottl * 1. Redistributions of source code must retain the above copyright 12171568Sscottl * notice, this list of conditions and the following disclaimer. 13171568Sscottl * 2. Redistributions in binary form must reproduce the above copyright 14171568Sscottl * notice, this list of conditions and the following disclaimer in the 15171568Sscottl * documentation and/or other materials provided with the distribution. 16171568Sscottl * 3. All advertising materials mentioning features or use of this software 17171568Sscottl * must display the following acknowledgement: 18171568Sscottl * This product includes software developed by the University of 19171568Sscottl * California, Berkeley and its contributors. 20171568Sscottl * 4. Neither the name of the University nor the names of its contributors 21171568Sscottl * may be used to endorse or promote products derived from this software 22171568Sscottl * without specific prior written permission. 23171568Sscottl * 24171568Sscottl * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25171568Sscottl * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26171568Sscottl * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27171568Sscottl * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28171568Sscottl * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29171568Sscottl * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30171568Sscottl * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31171568Sscottl * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32171568Sscottl * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33171568Sscottl * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34171568Sscottl * SUCH DAMAGE. */ 35171568Sscottl 36171568Sscottl/*static char *sccsid = "from: @(#)ctime.c 5.26 (Berkeley) 2/23/91";*/ 37171568Sscottl 38171568Sscottl/* 39171568Sscottl * This implementation of mktime is lifted straight from the NetBSD (BSD 4.4) 40171568Sscottl * version. I modified it slightly to divorce it from the internals of the 41171568Sscottl * ctime library. Thus this version can't use details of the internal 42171568Sscottl * timezone state file to figure out strange unnormalized struct tm values, 43171568Sscottl * as might result from someone doing date math on the tm struct then passing 44171568Sscottl * it to mktime. 45171568Sscottl * 46171568Sscottl * It just does as well as it can at normalizing the tm input, then does a 47171568Sscottl * binary search of the time space using the system's localtime() function. 48171568Sscottl * 49171568Sscottl * The original binary search was defective in that it didn't consider the 50171568Sscottl * setting of tm_isdst when comparing tm values, causing the search to be 51171568Sscottl * flubbed for times near the dst/standard time changeover. The original 52211095Sdes * code seems to make up for this by grubbing through the timezone info 53171568Sscottl * whenever the binary search barfed. Since I don't have that luxury in 54171568Sscottl * portable code, I have to take care of tm_isdst in the comparison routine. 55171568Sscottl * This requires knowing how many minutes offset dst is from standard time. 56171568Sscottl * 57171568Sscottl * So, if you live somewhere in the world where dst is not 60 minutes offset, 58171568Sscottl * and your vendor doesn't supply mktime(), you'll have to edit this variable 59171568Sscottl * by hand. Sorry about that. 60171568Sscottl */ 61171568Sscottl 62171568Sscottl#include <config.h> 63171568Sscottl#include "ntp_machine.h" 64171568Sscottl 65171568Sscottl#if !defined(HAVE_MKTIME) || ( !defined(HAVE_TIMEGM) && defined(WANT_TIMEGM) ) 66171568Sscottl 67171568Sscottl#if SIZEOF_TIME_T >= 8 68171568Sscottl#error libntp supplied mktime()/timegm() do not support 64-bit time_t 69171568Sscottl#endif 70171568Sscottl 71171568Sscottl#ifndef DSTMINUTES 72171568Sscottl#define DSTMINUTES 60 73171568Sscottl#endif 74171568Sscottl 75171568Sscottl#define FALSE 0 76171568Sscottl#define TRUE 1 77171568Sscottl 78171568Sscottl/* some constants from tzfile.h */ 79171568Sscottl#define SECSPERMIN 60 80171568Sscottl#define MINSPERHOUR 60 81171568Sscottl#define HOURSPERDAY 24 82171568Sscottl#define DAYSPERWEEK 7 83171568Sscottl#define DAYSPERNYEAR 365 84171568Sscottl#define DAYSPERLYEAR 366 85171568Sscottl#define SECSPERHOUR (SECSPERMIN * MINSPERHOUR) 86171568Sscottl#define SECSPERDAY ((long) SECSPERHOUR * HOURSPERDAY) 87171568Sscottl#define MONSPERYEAR 12 88171568Sscottl#define TM_YEAR_BASE 1900 89171568Sscottl#define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0) 90171568Sscottl 91171568Sscottlstatic int mon_lengths[2][MONSPERYEAR] = { 92171568Sscottl { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, 93171568Sscottl { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } 94171568Sscottl}; 95171568Sscottl 96171568Sscottlstatic int year_lengths[2] = { 97171568Sscottl DAYSPERNYEAR, DAYSPERLYEAR 98171568Sscottl}; 99171568Sscottl 100171568Sscottl/* 101171568Sscottl** Adapted from code provided by Robert Elz, who writes: 102171568Sscottl** The "best" way to do mktime I think is based on an idea of Bob 103171568Sscottl** Kridle's (so its said...) from a long time ago. (mtxinu!kridle now). 104171568Sscottl** It does a binary search of the time_t space. Since time_t's are 105171568Sscottl** just 32 bits, its a max of 32 iterations (even at 64 bits it 106171568Sscottl** would still be very reasonable). 107171568Sscottl*/ 108171568Sscottl 109171568Sscottl#ifndef WRONG 110171568Sscottl#define WRONG (-1) 111171568Sscottl#endif /* !defined WRONG */ 112171568Sscottl 113171568Sscottlstatic void 114171568Sscottlnormalize( 115171568Sscottl int * tensptr, 116171568Sscottl int * unitsptr, 117171568Sscottl int base 118171568Sscottl ) 119171568Sscottl{ 120171568Sscottl if (*unitsptr >= base) { 121171568Sscottl *tensptr += *unitsptr / base; 122171568Sscottl *unitsptr %= base; 123171568Sscottl } else if (*unitsptr < 0) { 124171568Sscottl --*tensptr; 125171568Sscottl *unitsptr += base; 126171568Sscottl if (*unitsptr < 0) { 127171568Sscottl *tensptr -= 1 + (-*unitsptr) / base; 128171568Sscottl *unitsptr = base - (-*unitsptr) % base; 129171568Sscottl } 130171568Sscottl } 131171568Sscottl} 132171568Sscottl 133171568Sscottlstatic struct tm * 134171568Sscottlmkdst( 135171568Sscottl struct tm * tmp 136171568Sscottl ) 137171568Sscottl{ 138171568Sscottl /* jds */ 139171568Sscottl static struct tm tmbuf; 140171568Sscottl 141171568Sscottl tmbuf = *tmp; 142171568Sscottl tmbuf.tm_isdst = 1; 143171568Sscottl tmbuf.tm_min += DSTMINUTES; 144171568Sscottl normalize(&tmbuf.tm_hour, &tmbuf.tm_min, MINSPERHOUR); 145171568Sscottl return &tmbuf; 146171568Sscottl} 147171568Sscottl 148171568Sscottlstatic int 149171568Sscottltmcomp( 150171568Sscottl register struct tm * atmp, 151171568Sscottl register struct tm * btmp 152211095Sdes ) 153171568Sscottl{ 154171568Sscottl register int result; 155171568Sscottl 156171568Sscottl /* compare down to the same day */ 157171568Sscottl 158171568Sscottl if ((result = (atmp->tm_year - btmp->tm_year)) == 0 && 159171568Sscottl (result = (atmp->tm_mon - btmp->tm_mon)) == 0) 160171568Sscottl result = (atmp->tm_mday - btmp->tm_mday); 161171568Sscottl 162171568Sscottl if(result != 0) 163171568Sscottl return result; 164171568Sscottl 165171568Sscottl /* get rid of one-sided dst bias */ 166171568Sscottl 167171568Sscottl if(atmp->tm_isdst == 1 && !btmp->tm_isdst) 168171568Sscottl btmp = mkdst(btmp); 169171568Sscottl else if(btmp->tm_isdst == 1 && !atmp->tm_isdst) 170171568Sscottl atmp = mkdst(atmp); 171171568Sscottl 172171568Sscottl /* compare the rest of the way */ 173171568Sscottl 174171568Sscottl if ((result = (atmp->tm_hour - btmp->tm_hour)) == 0 && 175171568Sscottl (result = (atmp->tm_min - btmp->tm_min)) == 0) 176171568Sscottl result = atmp->tm_sec - btmp->tm_sec; 177171568Sscottl return result; 178171568Sscottl} 179171568Sscottl 180171568Sscottl 181171568Sscottlstatic time_t 182171568Sscottltime2( 183171568Sscottl struct tm * tmp, 184171568Sscottl int * okayp, 185171568Sscottl int usezn 186171568Sscottl ) 187171568Sscottl{ 188171568Sscottl register int dir; 189171568Sscottl register int bits; 190171568Sscottl register int i; 191171568Sscottl register int saved_seconds; 192171568Sscottl time_t t; 193171568Sscottl struct tm yourtm, mytm; 194171568Sscottl 195171568Sscottl *okayp = FALSE; 196171568Sscottl yourtm = *tmp; 197171568Sscottl if (yourtm.tm_sec >= SECSPERMIN + 2 || yourtm.tm_sec < 0) 198171568Sscottl normalize(&yourtm.tm_min, &yourtm.tm_sec, SECSPERMIN); 199171568Sscottl normalize(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR); 200171568Sscottl normalize(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY); 201171568Sscottl normalize(&yourtm.tm_year, &yourtm.tm_mon, MONSPERYEAR); 202171568Sscottl while (yourtm.tm_mday <= 0) { 203171568Sscottl --yourtm.tm_year; 204171568Sscottl yourtm.tm_mday += 205 year_lengths[isleap(yourtm.tm_year + TM_YEAR_BASE)]; 206 } 207 for ( ; ; ) { 208 i = mon_lengths[isleap(yourtm.tm_year + 209 TM_YEAR_BASE)][yourtm.tm_mon]; 210 if (yourtm.tm_mday <= i) 211 break; 212 yourtm.tm_mday -= i; 213 if (++yourtm.tm_mon >= MONSPERYEAR) { 214 yourtm.tm_mon = 0; 215 ++yourtm.tm_year; 216 } 217 } 218 saved_seconds = yourtm.tm_sec; 219 yourtm.tm_sec = 0; 220 /* 221 ** Calculate the number of magnitude bits in a time_t 222 ** (this works regardless of whether time_t is 223 ** signed or unsigned, though lint complains if unsigned). 224 */ 225 for (bits = 0, t = 1; t > 0; ++bits, t <<= 1) 226 ; 227 /* 228 ** If time_t is signed, then 0 is the median value, 229 ** if time_t is unsigned, then 1 << bits is median. 230 */ 231 t = (t < 0) ? 0 : ((time_t) 1 << bits); 232 for ( ; ; ) { 233 if (usezn) 234 mytm = *localtime(&t); 235 else 236 mytm = *gmtime(&t); 237 dir = tmcomp(&mytm, &yourtm); 238 if (dir != 0) { 239 if (bits-- < 0) 240 return WRONG; 241 if (bits < 0) 242 --t; 243 else if (dir > 0) 244 t -= (time_t) 1 << bits; 245 else t += (time_t) 1 << bits; 246 continue; 247 } 248 if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst) 249 break; 250 251 return WRONG; 252 } 253 t += saved_seconds; 254 if (usezn) 255 *tmp = *localtime(&t); 256 else 257 *tmp = *gmtime(&t); 258 *okayp = TRUE; 259 return t; 260} 261#else 262int mktime_bs; 263#endif /* !HAVE_MKTIME || !HAVE_TIMEGM */ 264 265#ifndef HAVE_MKTIME 266static time_t 267time1( 268 struct tm * tmp 269 ) 270{ 271 register time_t t; 272 int okay; 273 274 if (tmp->tm_isdst > 1) 275 tmp->tm_isdst = 1; 276 t = time2(tmp, &okay, 1); 277 if (okay || tmp->tm_isdst < 0) 278 return t; 279 280 return WRONG; 281} 282 283time_t 284mktime( 285 struct tm * tmp 286 ) 287{ 288 return time1(tmp); 289} 290#endif /* !HAVE_MKTIME */ 291 292#ifdef WANT_TIMEGM 293#ifndef HAVE_TIMEGM 294time_t 295timegm( 296 struct tm * tmp 297 ) 298{ 299 register time_t t; 300 int okay; 301 302 tmp->tm_isdst = 0; 303 t = time2(tmp, &okay, 0); 304 if (okay || tmp->tm_isdst < 0) 305 return t; 306 307 return WRONG; 308} 309#endif /* !HAVE_TIMEGM */ 310#endif /* WANT_TIMEGM */ 311