2 Unix SMB/Netbios implementation.
4 time handling functions
5 Copyright (C) Andrew Tridgell 1992-1997
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 This stuff was largely rewritten by Paul Eggert <eggert@twinsun.com>
31 int extra_time_offset = 0;
33 extern int DEBUGLEVEL;
40 #define TIME_T_MIN ((time_t)0 < (time_t) -1 ? (time_t) 0 \
41 : ~ (time_t) 0 << (sizeof (time_t) * CHAR_BIT - 1))
44 #define TIME_T_MAX (~ (time_t) 0 - TIME_T_MIN)
49 /*******************************************************************
50 a gettimeofday wrapper
51 ********************************************************************/
52 void GetTimeOfDay(struct timeval *tval)
57 gettimeofday(tval,NULL);
61 #define TM_YEAR_BASE 1900
63 /*******************************************************************
64 yield the difference between *A and *B, in seconds, ignoring leap seconds
65 ********************************************************************/
66 static int tm_diff(struct tm *a, struct tm *b)
68 int ay = a->tm_year + (TM_YEAR_BASE - 1);
69 int by = b->tm_year + (TM_YEAR_BASE - 1);
70 int intervening_leap_days =
71 (ay/4 - by/4) - (ay/100 - by/100) + (ay/400 - by/400);
73 int days = 365*years + intervening_leap_days + (a->tm_yday - b->tm_yday);
74 int hours = 24*days + (a->tm_hour - b->tm_hour);
75 int minutes = 60*hours + (a->tm_min - b->tm_min);
76 int seconds = 60*minutes + (a->tm_sec - b->tm_sec);
80 /*******************************************************************
81 return the UTC offset in seconds west of UTC
82 ******************************************************************/
83 static int TimeZone(time_t t)
85 struct tm tm_utc = *(gmtime(&t));
86 return tm_diff(&tm_utc,localtime(&t));
90 /*******************************************************************
91 init the time differences
92 ********************************************************************/
95 serverzone = TimeZone(time(NULL));
96 DEBUG(4,("Serverzone is %d\n",serverzone));
100 /*******************************************************************
101 return the same value as TimeZone, but it should be more efficient.
103 We keep a table of DST offsets to prevent calling localtime() on each
104 call of this function. This saves a LOT of time on many unixes.
106 Updated by Paul Eggert <eggert@twinsun.com>
107 ********************************************************************/
108 static int TimeZoneFaster(time_t t)
110 static struct dst_table {time_t start,end; int zone;} *dst_table = NULL;
111 static int table_size = 0;
115 if (t == 0) t = time(NULL);
117 /* Tunis has a 8 day DST region, we need to be careful ... */
118 #define MAX_DST_WIDTH (365*24*60*60)
119 #define MAX_DST_SKIP (7*24*60*60)
121 for (i=0;i<table_size;i++)
122 if (t >= dst_table[i].start && t <= dst_table[i].end) break;
125 zone = dst_table[i].zone;
130 dst_table = (struct dst_table *)Realloc(dst_table,
131 sizeof(dst_table[0])*(i+1));
137 dst_table[i].zone = zone;
138 dst_table[i].start = dst_table[i].end = t;
140 /* no entry will cover more than 6 months */
141 low = t - MAX_DST_WIDTH/2;
145 high = t + MAX_DST_WIDTH/2;
149 /* widen the new entry using two bisection searches */
150 while (low+60*60 < dst_table[i].start) {
151 if (dst_table[i].start - low > MAX_DST_SKIP*2)
152 t = dst_table[i].start - MAX_DST_SKIP;
154 t = low + (dst_table[i].start-low)/2;
155 if (TimeZone(t) == zone)
156 dst_table[i].start = t;
161 while (high-60*60 > dst_table[i].end) {
162 if (high - dst_table[i].end > MAX_DST_SKIP*2)
163 t = dst_table[i].end + MAX_DST_SKIP;
165 t = high - (high-dst_table[i].end)/2;
166 if (TimeZone(t) == zone)
167 dst_table[i].end = t;
172 DEBUG(1,("Added DST entry from %s ",
173 asctime(localtime(&dst_table[i].start))));
174 DEBUG(1,("to %s (%d)\n",asctime(localtime(&dst_table[i].end)),
182 /****************************************************************************
183 return the UTC offset in seconds west of UTC, adjusted for extra time offset
184 **************************************************************************/
185 int TimeDiff(time_t t)
187 return TimeZoneFaster(t) + 60*extra_time_offset;
191 /****************************************************************************
192 return the UTC offset in seconds west of UTC, adjusted for extra time
193 offset, for a local time value. If ut = lt + LocTimeDiff(lt), then
194 lt = ut - TimeDiff(ut), but the converse does not necessarily hold near
195 daylight savings transitions because some local times are ambiguous.
196 LocTimeDiff(t) equals TimeDiff(t) except near daylight savings transitions.
197 +**************************************************************************/
198 static int LocTimeDiff(time_t lte)
200 time_t lt = lte - 60*extra_time_offset;
201 int d = TimeZoneFaster(lt);
204 /* if overflow occurred, ignore all the adjustments so far */
205 if (((lte < lt) ^ (extra_time_offset < 0)) | ((t < lt) ^ (d < 0)))
208 /* now t should be close enough to the true UTC to yield the right answer */
213 /****************************************************************************
214 try to optimise the localtime call, it can be quite expenive on some machines
215 ****************************************************************************/
216 struct tm *LocalTime(time_t *t)
226 #define TIME_FIXUP_CONSTANT (369.0*365.25*24*60*60-(3.0*24*60*60+6.0*60*60))
228 /****************************************************************************
229 interpret an 8 byte "filetime" structure to a time_t
230 It's originally in "100ns units since jan 1st 1601"
232 It appears to be kludge-GMT (at least for file listings). This means
233 its the GMT you get by taking a localtime and adding the
234 serverzone. This is NOT the same as GMT in some cases. This routine
235 converts this to real GMT.
236 ****************************************************************************/
237 time_t interpret_long_date(char *p)
245 if (thigh == 0) return(0);
247 d = ((double)thigh)*4.0*(double)(1<<30);
248 d += (tlow&0xFFF00000);
251 /* now adjust by 369 years to make the secs since 1970 */
252 d -= TIME_FIXUP_CONSTANT;
254 if (!(TIME_T_MIN <= d && d <= TIME_T_MAX))
257 ret = (time_t)(d+0.5);
259 /* this takes us from kludge-GMT to real GMT */
261 ret += LocTimeDiff(ret);
267 /****************************************************************************
268 put a 8 byte filetime from a time_t
269 This takes real GMT as input and converts to kludge-GMT
270 ****************************************************************************/
271 void put_long_date(char *p,time_t t)
277 SIVAL(p,0,0); SIVAL(p,4,0);
281 /* this converts GMT to kludge-GMT */
282 t -= TimeDiff(t) - serverzone;
286 d += TIME_FIXUP_CONSTANT;
290 thigh = (uint32)(d * (1.0/(4.0*(double)(1<<30))));
291 tlow = (uint32)(d - ((double)thigh)*4.0*(double)(1<<30));
298 /****************************************************************************
299 check if it's a null mtime
300 ****************************************************************************/
301 static BOOL null_mtime(time_t mtime)
303 if (mtime == 0 || mtime == 0xFFFFFFFF || mtime == (time_t)-1)
308 /*******************************************************************
309 create a 16 bit dos packed date
310 ********************************************************************/
311 static uint16 make_dos_date1(time_t unixdate,struct tm *t)
314 ret = (((unsigned)(t->tm_mon+1)) >> 3) | ((t->tm_year-80) << 1);
315 ret = ((ret&0xFF)<<8) | (t->tm_mday | (((t->tm_mon+1) & 0x7) << 5));
319 /*******************************************************************
320 create a 16 bit dos packed time
321 ********************************************************************/
322 static uint16 make_dos_time1(time_t unixdate,struct tm *t)
325 ret = ((((unsigned)t->tm_min >> 3)&0x7) | (((unsigned)t->tm_hour) << 3));
326 ret = ((ret&0xFF)<<8) | ((t->tm_sec/2) | ((t->tm_min & 0x7) << 5));
330 /*******************************************************************
331 create a 32 bit dos packed date/time from some parameters
332 This takes a GMT time and returns a packed localtime structure
333 ********************************************************************/
334 static uint32 make_dos_date(time_t unixdate)
339 t = LocalTime(&unixdate);
341 ret = make_dos_date1(unixdate,t);
342 ret = ((ret&0xFFFF)<<16) | make_dos_time1(unixdate,t);
347 /*******************************************************************
348 put a dos date into a buffer (time/date format)
349 This takes GMT time and puts local time in the buffer
350 ********************************************************************/
351 void put_dos_date(char *buf,int offset,time_t unixdate)
353 uint32 x = make_dos_date(unixdate);
357 /*******************************************************************
358 put a dos date into a buffer (date/time format)
359 This takes GMT time and puts local time in the buffer
360 ********************************************************************/
361 void put_dos_date2(char *buf,int offset,time_t unixdate)
363 uint32 x = make_dos_date(unixdate);
364 x = ((x&0xFFFF)<<16) | ((x&0xFFFF0000)>>16);
368 /*******************************************************************
369 put a dos 32 bit "unix like" date into a buffer. This routine takes
370 GMT and converts it to LOCAL time before putting it (most SMBs assume
371 localtime for this sort of date)
372 ********************************************************************/
373 void put_dos_date3(char *buf,int offset,time_t unixdate)
375 if (!null_mtime(unixdate))
376 unixdate -= TimeDiff(unixdate);
377 SIVAL(buf,offset,unixdate);
380 /*******************************************************************
381 interpret a 32 bit dos packed date/time to some parameters
382 ********************************************************************/
383 static void interpret_dos_date(uint32 date,int *year,int *month,int *day,int *hour,int *minute,int *second)
387 p0=date&0xFF; p1=((date&0xFF00)>>8)&0xFF;
388 p2=((date&0xFF0000)>>16)&0xFF; p3=((date&0xFF000000)>>24)&0xFF;
390 *second = 2*(p0 & 0x1F);
391 *minute = ((p0>>5)&0xFF) + ((p1&0x7)<<3);
392 *hour = (p1>>3)&0xFF;
394 *month = ((p2>>5)&0xFF) + ((p3&0x1)<<3) - 1;
395 *year = ((p3>>1)&0xFF) + 80;
398 /*******************************************************************
399 create a unix date (int GMT) from a dos date (which is actually in
401 ********************************************************************/
402 time_t make_unix_date(void *date_ptr)
408 dos_date = IVAL(date_ptr,0);
410 if (dos_date == 0) return(0);
412 interpret_dos_date(dos_date,&t.tm_year,&t.tm_mon,
413 &t.tm_mday,&t.tm_hour,&t.tm_min,&t.tm_sec);
416 /* mktime() also does the local to GMT time conversion for us */
422 /*******************************************************************
423 like make_unix_date() but the words are reversed
424 ********************************************************************/
425 time_t make_unix_date2(void *date_ptr)
429 x = IVAL(date_ptr,0);
430 x2 = ((x&0xFFFF)<<16) | ((x&0xFFFF0000)>>16);
433 return(make_unix_date((void *)&x));
436 /*******************************************************************
437 create a unix GMT date from a dos date in 32 bit "unix like" format
438 these generally arrive as localtimes, with corresponding DST
439 ******************************************************************/
440 time_t make_unix_date3(void *date_ptr)
442 time_t t = IVAL(date_ptr,0);
448 /****************************************************************************
449 set the time on a file
450 ****************************************************************************/
451 BOOL set_filetime(char *fname,time_t mtime)
453 struct utimbuf times;
455 if (null_mtime(mtime)) return(True);
457 times.modtime = times.actime = mtime;
459 if (sys_utime(fname,×)) {
460 DEBUG(4,("set_filetime(%s) failed: %s\n",fname,strerror(errno)));
467 /****************************************************************************
468 return the date and time as a string
469 ****************************************************************************/
470 char *timestring(void )
472 static fstring TimeBuf;
473 time_t t = time(NULL);
474 struct tm *tm = LocalTime(&t);
477 fstrcpy(TimeBuf, asctime(tm));
478 #elif defined(CLIX) || defined(CONVEX)
479 strftime(TimeBuf,100,"%m/%d/%y %I:%M:%S %p",tm);
481 strftime(TimeBuf,100,"%D %r",tm);
482 #elif defined(TZ_TIME)
484 int zone = TimeDiff(t);
485 int absZoneMinutes = (zone<0 ? -zone : zone) / 60;
486 size_t len = strftime(TimeBuf,sizeof(TimeBuf)-6,"%D %T",tm);
487 sprintf(TimeBuf+len," %c%02d%02d",
488 zone<0?'+':'-',absZoneMinutes/60,absZoneMinutes%60);
491 strftime(TimeBuf,100,"%D %T",tm);