2 Unix SMB/Netbios implementation.
4 time handling functions
5 Copyright (C) Andrew Tridgell 1992-1998
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)
54 #ifdef HAVE_GETTIMEOFDAY_TZ
55 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);
81 /*******************************************************************
82 return the UTC offset in seconds west of UTC, or 0 if it cannot be determined
83 ******************************************************************/
84 static int TimeZone(time_t t)
86 struct tm *tm = gmtime(&t);
94 return tm_diff(&tm_utc,tm);
99 /*******************************************************************
100 init the time differences
101 ********************************************************************/
104 serverzone = TimeZone(time(NULL));
106 if ((serverzone % 60) != 0) {
107 DEBUG(1,("WARNING: Your timezone is not a multiple of 1 minute.\n"));
110 DEBUG(4,("Serverzone is %d\n",serverzone));
114 /*******************************************************************
115 return the same value as TimeZone, but it should be more efficient.
117 We keep a table of DST offsets to prevent calling localtime() on each
118 call of this function. This saves a LOT of time on many unixes.
120 Updated by Paul Eggert <eggert@twinsun.com>
121 ********************************************************************/
122 static int TimeZoneFaster(time_t t)
124 static struct dst_table {time_t start,end; int zone;} *dst_table = NULL;
125 static int table_size = 0;
129 if (t == 0) t = time(NULL);
131 /* Tunis has a 8 day DST region, we need to be careful ... */
132 #define MAX_DST_WIDTH (365*24*60*60)
133 #define MAX_DST_SKIP (7*24*60*60)
135 for (i=0;i<table_size;i++)
136 if (t >= dst_table[i].start && t <= dst_table[i].end) break;
139 zone = dst_table[i].zone;
144 dst_table = (struct dst_table *)Realloc(dst_table,
145 sizeof(dst_table[0])*(i+1));
151 dst_table[i].zone = zone;
152 dst_table[i].start = dst_table[i].end = t;
154 /* no entry will cover more than 6 months */
155 low = t - MAX_DST_WIDTH/2;
159 high = t + MAX_DST_WIDTH/2;
163 /* widen the new entry using two bisection searches */
164 while (low+60*60 < dst_table[i].start) {
165 if (dst_table[i].start - low > MAX_DST_SKIP*2)
166 t = dst_table[i].start - MAX_DST_SKIP;
168 t = low + (dst_table[i].start-low)/2;
169 if (TimeZone(t) == zone)
170 dst_table[i].start = t;
175 while (high-60*60 > dst_table[i].end) {
176 if (high - dst_table[i].end > MAX_DST_SKIP*2)
177 t = dst_table[i].end + MAX_DST_SKIP;
179 t = high - (high-dst_table[i].end)/2;
180 if (TimeZone(t) == zone)
181 dst_table[i].end = t;
186 DEBUG(1,("Added DST entry from %s ",
187 asctime(localtime(&dst_table[i].start))));
188 DEBUG(1,("to %s (%d)\n",asctime(localtime(&dst_table[i].end)),
196 /****************************************************************************
197 return the UTC offset in seconds west of UTC, adjusted for extra time offset
198 **************************************************************************/
199 int TimeDiff(time_t t)
201 return TimeZoneFaster(t) + 60*extra_time_offset;
205 /****************************************************************************
206 return the UTC offset in seconds west of UTC, adjusted for extra time
207 offset, for a local time value. If ut = lt + LocTimeDiff(lt), then
208 lt = ut - TimeDiff(ut), but the converse does not necessarily hold near
209 daylight savings transitions because some local times are ambiguous.
210 LocTimeDiff(t) equals TimeDiff(t) except near daylight savings transitions.
211 +**************************************************************************/
212 static int LocTimeDiff(time_t lte)
214 time_t lt = lte - 60*extra_time_offset;
215 int d = TimeZoneFaster(lt);
218 /* if overflow occurred, ignore all the adjustments so far */
219 if (((lte < lt) ^ (extra_time_offset < 0)) | ((t < lt) ^ (d < 0)))
222 /* now t should be close enough to the true UTC to yield the right answer */
227 /****************************************************************************
228 try to optimise the localtime call, it can be quite expensive on some machines
229 ****************************************************************************/
230 struct tm *LocalTime(time_t *t)
239 /****************************************************************************
240 take an NTTIME structure, containing high / low time. convert to unix time.
241 lkclXXXX this may need 2 SIVALs not a memcpy. we'll see...
242 ****************************************************************************/
243 time_t interpret_nt_time(NTTIME *t)
246 memcpy(data, t, sizeof(data));
247 return interpret_long_date(data);
251 #define TIME_FIXUP_CONSTANT (369.0*365.25*24*60*60-(3.0*24*60*60+6.0*60*60))
253 /****************************************************************************
254 interpret an 8 byte "filetime" structure to a time_t
255 It's originally in "100ns units since jan 1st 1601"
257 It appears to be kludge-GMT (at least for file listings). This means
258 its the GMT you get by taking a localtime and adding the
259 serverzone. This is NOT the same as GMT in some cases. This routine
260 converts this to real GMT.
261 ****************************************************************************/
262 time_t interpret_long_date(char *p)
267 /* The next two lines are a fix needed for the
268 broken SCO compiler. JRA. */
269 time_t l_time_min = TIME_T_MIN;
270 time_t l_time_max = TIME_T_MAX;
274 if (thigh == 0) return(0);
276 d = ((double)thigh)*4.0*(double)(1<<30);
277 d += (tlow&0xFFF00000);
280 /* now adjust by 369 years to make the secs since 1970 */
281 d -= TIME_FIXUP_CONSTANT;
283 if (!(l_time_min <= d && d <= l_time_max))
286 ret = (time_t)(d+0.5);
288 /* this takes us from kludge-GMT to real GMT */
290 ret += LocTimeDiff(ret);
296 /****************************************************************************
297 put a 8 byte filetime from a time_t
298 This takes real GMT as input and converts to kludge-GMT
299 ****************************************************************************/
300 void put_long_date(char *p,time_t t)
306 SIVAL(p,0,0); SIVAL(p,4,0);
310 /* this converts GMT to kludge-GMT */
311 t -= LocTimeDiff(t) - serverzone;
315 d += TIME_FIXUP_CONSTANT;
319 thigh = (uint32)(d * (1.0/(4.0*(double)(1<<30))));
320 tlow = (uint32)(d - ((double)thigh)*4.0*(double)(1<<30));
327 /****************************************************************************
328 check if it's a null mtime
329 ****************************************************************************/
330 BOOL null_mtime(time_t mtime)
332 if (mtime == 0 || mtime == 0xFFFFFFFF || mtime == (time_t)-1)
337 /*******************************************************************
338 create a 16 bit dos packed date
339 ********************************************************************/
340 static uint16 make_dos_date1(struct tm *t)
343 ret = (((unsigned)(t->tm_mon+1)) >> 3) | ((t->tm_year-80) << 1);
344 ret = ((ret&0xFF)<<8) | (t->tm_mday | (((t->tm_mon+1) & 0x7) << 5));
348 /*******************************************************************
349 create a 16 bit dos packed time
350 ********************************************************************/
351 static uint16 make_dos_time1(struct tm *t)
354 ret = ((((unsigned)t->tm_min >> 3)&0x7) | (((unsigned)t->tm_hour) << 3));
355 ret = ((ret&0xFF)<<8) | ((t->tm_sec/2) | ((t->tm_min & 0x7) << 5));
359 /*******************************************************************
360 create a 32 bit dos packed date/time from some parameters
361 This takes a GMT time and returns a packed localtime structure
362 ********************************************************************/
363 static uint32 make_dos_date(time_t unixdate)
368 t = LocalTime(&unixdate);
372 ret = make_dos_date1(t);
373 ret = ((ret&0xFFFF)<<16) | make_dos_time1(t);
378 /*******************************************************************
379 put a dos date into a buffer (time/date format)
380 This takes GMT time and puts local time in the buffer
381 ********************************************************************/
382 void put_dos_date(char *buf,int offset,time_t unixdate)
384 uint32 x = make_dos_date(unixdate);
388 /*******************************************************************
389 put a dos date into a buffer (date/time format)
390 This takes GMT time and puts local time in the buffer
391 ********************************************************************/
392 void put_dos_date2(char *buf,int offset,time_t unixdate)
394 uint32 x = make_dos_date(unixdate);
395 x = ((x&0xFFFF)<<16) | ((x&0xFFFF0000)>>16);
399 /*******************************************************************
400 put a dos 32 bit "unix like" date into a buffer. This routine takes
401 GMT and converts it to LOCAL time before putting it (most SMBs assume
402 localtime for this sort of date)
403 ********************************************************************/
404 void put_dos_date3(char *buf,int offset,time_t unixdate)
406 if (!null_mtime(unixdate))
407 unixdate -= TimeDiff(unixdate);
408 SIVAL(buf,offset,unixdate);
411 /*******************************************************************
412 interpret a 32 bit dos packed date/time to some parameters
413 ********************************************************************/
414 static void interpret_dos_date(uint32 date,int *year,int *month,int *day,int *hour,int *minute,int *second)
418 p0=date&0xFF; p1=((date&0xFF00)>>8)&0xFF;
419 p2=((date&0xFF0000)>>16)&0xFF; p3=((date&0xFF000000)>>24)&0xFF;
421 *second = 2*(p0 & 0x1F);
422 *minute = ((p0>>5)&0xFF) + ((p1&0x7)<<3);
423 *hour = (p1>>3)&0xFF;
425 *month = ((p2>>5)&0xFF) + ((p3&0x1)<<3) - 1;
426 *year = ((p3>>1)&0xFF) + 80;
429 /*******************************************************************
430 create a unix date (int GMT) from a dos date (which is actually in
432 ********************************************************************/
433 time_t make_unix_date(void *date_ptr)
439 dos_date = IVAL(date_ptr,0);
441 if (dos_date == 0) return(0);
443 interpret_dos_date(dos_date,&t.tm_year,&t.tm_mon,
444 &t.tm_mday,&t.tm_hour,&t.tm_min,&t.tm_sec);
447 /* mktime() also does the local to GMT time conversion for us */
453 /*******************************************************************
454 like make_unix_date() but the words are reversed
455 ********************************************************************/
456 time_t make_unix_date2(void *date_ptr)
460 x = IVAL(date_ptr,0);
461 x2 = ((x&0xFFFF)<<16) | ((x&0xFFFF0000)>>16);
464 return(make_unix_date((void *)&x));
467 /*******************************************************************
468 create a unix GMT date from a dos date in 32 bit "unix like" format
469 these generally arrive as localtimes, with corresponding DST
470 ******************************************************************/
471 time_t make_unix_date3(void *date_ptr)
473 time_t t = (time_t)IVAL(date_ptr,0);
480 /***************************************************************************
481 return a HTTP/1.0 time string
482 ***************************************************************************/
483 char *http_timestring(time_t t)
486 struct tm *tm = LocalTime(&t);
489 slprintf(buf,sizeof(buf)-1,"%ld seconds since the Epoch",(long)t);
491 #ifndef HAVE_STRFTIME
492 fstrcpy(buf, asctime(tm));
493 #else /* !HAVE_STRFTIME */
494 strftime(buf, sizeof(buf)-1, "%a, %d %b %Y %H:%M:%S %Z", tm);
495 #endif /* !HAVE_STRFTIME */
501 /****************************************************************************
502 return the date and time as a string
503 ****************************************************************************/
504 char *timestring(void )
506 static fstring TimeBuf;
507 time_t t = time(NULL);
508 struct tm *tm = LocalTime(&t);
511 slprintf(TimeBuf,sizeof(TimeBuf)-1,"%ld seconds since the Epoch",(long)t);
514 strftime(TimeBuf,100,"%Y/%m/%d %T",tm);
516 fstrcpy(TimeBuf, asctime(tm));
522 /****************************************************************************
523 return the best approximation to a 'create time' under UNIX from a stat
525 ****************************************************************************/
527 time_t get_create_time(SMB_STRUCT_STAT *st,BOOL fake_dirs)
531 if(S_ISDIR(st->st_mode) && fake_dirs)
532 return (time_t)315493200L; /* 1/1/1980 */
534 ret = MIN(st->st_ctime, st->st_mtime);
535 ret1 = MIN(ret, st->st_atime);
537 if(ret1 != (time_t)0)
541 * One of ctime, mtime or atime was zero (probably atime).
542 * Just return MIN(ctime, mtime).