2 * Copyright (c) 1987, 1989 Regents of the University of California.
5 * This code is derived from software contributed to Berkeley by
6 * Arthur David Olson of the National Cancer Institute.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. 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.
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
36 /*static char *sccsid = "from: @(#)ctime.c 5.26 (Berkeley) 2/23/91";*/
39 * This implementation of mktime is lifted straight from the NetBSD (BSD 4.4)
40 * version. I modified it slightly to divorce it from the internals of the
41 * ctime library. Thus this version can't use details of the internal
42 * timezone state file to figure out strange unnormalized struct tm values,
43 * as might result from someone doing date math on the tm struct then passing
46 * It just does as well as it can at normalizing the tm input, then does a
47 * binary search of the time space using the system's localtime() function.
49 * The original binary search was defective in that it didn't consider the
50 * setting of tm_isdst when comparing tm values, causing the search to be
51 * flubbed for times near the dst/standard time changeover. The original
52 * code seems to make up for this by grubbing through the timezone info
53 * whenever the binary search barfed. Since I don't have that luxury in
54 * portable code, I have to take care of tm_isdst in the comparison routine.
55 * This requires knowing how many minutes offset dst is from standard time.
57 * So, if you live somewhere in the world where dst is not 60 minutes offset,
58 * and your vendor doesn't supply mktime(), you'll have to edit this variable
59 * by hand. Sorry about that.
62 #include "ntp_machine.h"
64 #if !defined(HAVE_MKTIME) || !defined(HAVE_TIMEGM)
73 /* some constants from tzfile.h */
75 #define MINSPERHOUR 60
76 #define HOURSPERDAY 24
78 #define DAYSPERNYEAR 365
79 #define DAYSPERLYEAR 366
80 #define SECSPERHOUR (SECSPERMIN * MINSPERHOUR)
81 #define SECSPERDAY ((long) SECSPERHOUR * HOURSPERDAY)
82 #define MONSPERYEAR 12
83 #define TM_YEAR_BASE 1900
84 #define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)
86 static int mon_lengths[2][MONSPERYEAR] = {
87 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
88 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
91 static int year_lengths[2] = {
92 DAYSPERNYEAR, DAYSPERLYEAR
96 ** Adapted from code provided by Robert Elz, who writes:
97 ** The "best" way to do mktime I think is based on an idea of Bob
98 ** Kridle's (so its said...) from a long time ago. (mtxinu!kridle now).
99 ** It does a binary search of the time_t space. Since time_t's are
100 ** just 32 bits, its a max of 32 iterations (even at 64 bits it
101 ** would still be very reasonable).
106 #endif /* !defined WRONG */
115 if (*unitsptr >= base) {
116 *tensptr += *unitsptr / base;
118 } else if (*unitsptr < 0) {
122 *tensptr -= 1 + (-*unitsptr) / base;
123 *unitsptr = base - (-*unitsptr) % base;
134 static struct tm tmbuf;
138 tmbuf.tm_min += DSTMINUTES;
139 normalize(&tmbuf.tm_hour, &tmbuf.tm_min, MINSPERHOUR);
145 register struct tm * atmp,
146 register struct tm * btmp
151 /* compare down to the same day */
153 if ((result = (atmp->tm_year - btmp->tm_year)) == 0 &&
154 (result = (atmp->tm_mon - btmp->tm_mon)) == 0)
155 result = (atmp->tm_mday - btmp->tm_mday);
160 /* get rid of one-sided dst bias */
162 if(atmp->tm_isdst == 1 && !btmp->tm_isdst)
164 else if(btmp->tm_isdst == 1 && !atmp->tm_isdst)
167 /* compare the rest of the way */
169 if ((result = (atmp->tm_hour - btmp->tm_hour)) == 0 &&
170 (result = (atmp->tm_min - btmp->tm_min)) == 0)
171 result = atmp->tm_sec - btmp->tm_sec;
186 register int saved_seconds;
188 struct tm yourtm, mytm;
192 if (yourtm.tm_sec >= SECSPERMIN + 2 || yourtm.tm_sec < 0)
193 normalize(&yourtm.tm_min, &yourtm.tm_sec, SECSPERMIN);
194 normalize(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR);
195 normalize(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY);
196 normalize(&yourtm.tm_year, &yourtm.tm_mon, MONSPERYEAR);
197 while (yourtm.tm_mday <= 0) {
200 year_lengths[isleap(yourtm.tm_year + TM_YEAR_BASE)];
203 i = mon_lengths[isleap(yourtm.tm_year +
204 TM_YEAR_BASE)][yourtm.tm_mon];
205 if (yourtm.tm_mday <= i)
208 if (++yourtm.tm_mon >= MONSPERYEAR) {
213 saved_seconds = yourtm.tm_sec;
216 ** Calculate the number of magnitude bits in a time_t
217 ** (this works regardless of whether time_t is
218 ** signed or unsigned, though lint complains if unsigned).
220 for (bits = 0, t = 1; t > 0; ++bits, t <<= 1)
223 ** If time_t is signed, then 0 is the median value,
224 ** if time_t is unsigned, then 1 << bits is median.
226 t = (t < 0) ? 0 : ((time_t) 1 << bits);
229 mytm = *localtime(&t);
232 dir = tmcomp(&mytm, &yourtm);
239 t -= (time_t) 1 << bits;
240 else t += (time_t) 1 << bits;
243 if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst)
250 *tmp = *localtime(&t);
258 #endif /* !HAVE_MKTIME || !HAVE_TIMEGM */
269 if (tmp->tm_isdst > 1)
271 t = time2(tmp, &okay, 1);
272 if (okay || tmp->tm_isdst < 0)
285 #endif /* !HAVE_MKTIME */
297 t = time2(tmp, &okay, 0);
298 if (okay || tmp->tm_isdst < 0)
303 #endif /* !HAVE_TIMEGM */