This is time.c in view mode; [Download] [Up]
/*
Unix SMB/Netbios implementation.
Version 1.9.
time handling functions
Copyright (C) Andrew Tridgell 1992-1998
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "includes.h"
/*
This stuff was largely rewritten by Paul Eggert <eggert@twinsun.com>
in May 1996
*/
int serverzone=0;
int extra_time_offset = 0;
extern int DEBUGLEVEL;
#ifndef CHAR_BIT
#define CHAR_BIT 8
#endif
#ifndef TIME_T_MIN
#define TIME_T_MIN ((time_t)0 < (time_t) -1 ? (time_t) 0 \
: ~ (time_t) 0 << (sizeof (time_t) * CHAR_BIT - 1))
#endif
#ifndef TIME_T_MAX
#define TIME_T_MAX (~ (time_t) 0 - TIME_T_MIN)
#endif
/*******************************************************************
a gettimeofday wrapper
********************************************************************/
void GetTimeOfDay(struct timeval *tval)
{
#ifdef GETTIMEOFDAY1
gettimeofday(tval);
#else
gettimeofday(tval,NULL);
#endif
}
#define TM_YEAR_BASE 1900
/*******************************************************************
yield the difference between *A and *B, in seconds, ignoring leap seconds
********************************************************************/
static int tm_diff(struct tm *a, struct tm *b)
{
int ay = a->tm_year + (TM_YEAR_BASE - 1);
int by = b->tm_year + (TM_YEAR_BASE - 1);
int intervening_leap_days =
(ay/4 - by/4) - (ay/100 - by/100) + (ay/400 - by/400);
int years = ay - by;
int days = 365*years + intervening_leap_days + (a->tm_yday - b->tm_yday);
int hours = 24*days + (a->tm_hour - b->tm_hour);
int minutes = 60*hours + (a->tm_min - b->tm_min);
int seconds = 60*minutes + (a->tm_sec - b->tm_sec);
return seconds;
}
/*******************************************************************
return the UTC offset in seconds west of UTC, or 0 if it cannot be determined
******************************************************************/
static int TimeZone(time_t t)
{
struct tm *tm = gmtime(&t);
struct tm tm_utc;
if (!tm)
return 0;
tm_utc = *tm;
tm = localtime(&t);
if (!tm)
return 0;
return tm_diff(&tm_utc,tm);
}
/*******************************************************************
init the time differences
********************************************************************/
void TimeInit(void)
{
serverzone = TimeZone(time(NULL));
if ((serverzone % 60) != 0) {
DEBUG(1,("WARNING: Your timezone is not a multiple of 1 minute.\n"));
}
DEBUG(4,("Serverzone is %d\n",serverzone));
}
/*******************************************************************
return the same value as TimeZone, but it should be more efficient.
We keep a table of DST offsets to prevent calling localtime() on each
call of this function. This saves a LOT of time on many unixes.
Updated by Paul Eggert <eggert@twinsun.com>
********************************************************************/
static int TimeZoneFaster(time_t t)
{
static struct dst_table {time_t start,end; int zone;} *dst_table = NULL;
static int table_size = 0;
int i;
int zone = 0;
if (t == 0) t = time(NULL);
/* Tunis has a 8 day DST region, we need to be careful ... */
#define MAX_DST_WIDTH (365*24*60*60)
#define MAX_DST_SKIP (7*24*60*60)
for (i=0;i<table_size;i++)
if (t >= dst_table[i].start && t <= dst_table[i].end) break;
if (i<table_size) {
zone = dst_table[i].zone;
} else {
time_t low,high;
zone = TimeZone(t);
dst_table = (struct dst_table *)Realloc(dst_table,
sizeof(dst_table[0])*(i+1));
if (!dst_table) {
table_size = 0;
} else {
table_size++;
dst_table[i].zone = zone;
dst_table[i].start = dst_table[i].end = t;
/* no entry will cover more than 6 months */
low = t - MAX_DST_WIDTH/2;
if (t < low)
low = TIME_T_MIN;
high = t + MAX_DST_WIDTH/2;
if (high < t)
high = TIME_T_MAX;
/* widen the new entry using two bisection searches */
while (low+60*60 < dst_table[i].start) {
if (dst_table[i].start - low > MAX_DST_SKIP*2)
t = dst_table[i].start - MAX_DST_SKIP;
else
t = low + (dst_table[i].start-low)/2;
if (TimeZone(t) == zone)
dst_table[i].start = t;
else
low = t;
}
while (high-60*60 > dst_table[i].end) {
if (high - dst_table[i].end > MAX_DST_SKIP*2)
t = dst_table[i].end + MAX_DST_SKIP;
else
t = high - (high-dst_table[i].end)/2;
if (TimeZone(t) == zone)
dst_table[i].end = t;
else
high = t;
}
#if 0
DEBUG(1,("Added DST entry from %s ",
asctime(localtime(&dst_table[i].start))));
DEBUG(1,("to %s (%d)\n",asctime(localtime(&dst_table[i].end)),
dst_table[i].zone));
#endif
}
}
return zone;
}
/****************************************************************************
return the UTC offset in seconds west of UTC, adjusted for extra time offset
**************************************************************************/
int TimeDiff(time_t t)
{
return TimeZoneFaster(t) + 60*extra_time_offset;
}
/****************************************************************************
return the UTC offset in seconds west of UTC, adjusted for extra time
offset, for a local time value. If ut = lt + LocTimeDiff(lt), then
lt = ut - TimeDiff(ut), but the converse does not necessarily hold near
daylight savings transitions because some local times are ambiguous.
LocTimeDiff(t) equals TimeDiff(t) except near daylight savings transitions.
+**************************************************************************/
static int LocTimeDiff(time_t lte)
{
time_t lt = lte - 60*extra_time_offset;
int d = TimeZoneFaster(lt);
time_t t = lt + d;
/* if overflow occurred, ignore all the adjustments so far */
if (((lte < lt) ^ (extra_time_offset < 0)) | ((t < lt) ^ (d < 0)))
t = lte;
/* now t should be close enough to the true UTC to yield the right answer */
return TimeDiff(t);
}
/****************************************************************************
try to optimise the localtime call, it can be quite expensive on some machines
****************************************************************************/
struct tm *LocalTime(time_t *t)
{
time_t t2 = *t;
t2 -= TimeDiff(t2);
return(gmtime(&t2));
}
#define TIME_FIXUP_CONSTANT (369.0*365.25*24*60*60-(3.0*24*60*60+6.0*60*60))
/****************************************************************************
interpret an 8 byte "filetime" structure to a time_t
It's originally in "100ns units since jan 1st 1601"
It appears to be kludge-GMT (at least for file listings). This means
its the GMT you get by taking a localtime and adding the
serverzone. This is NOT the same as GMT in some cases. This routine
converts this to real GMT.
****************************************************************************/
time_t interpret_long_date(char *p)
{
double d;
time_t ret;
uint32 tlow,thigh;
/* The next two lines are a fix needed for the
broken SCO compiler. JRA. */
time_t l_time_min = TIME_T_MIN;
time_t l_time_max = TIME_T_MAX;
tlow = IVAL(p,0);
thigh = IVAL(p,4);
if (thigh == 0) return(0);
d = ((double)thigh)*4.0*(double)(1<<30);
d += (tlow&0xFFF00000);
d *= 1.0e-7;
/* now adjust by 369 years to make the secs since 1970 */
d -= TIME_FIXUP_CONSTANT;
if (!(l_time_min <= d && d <= l_time_max))
return(0);
ret = (time_t)(d+0.5);
/* this takes us from kludge-GMT to real GMT */
ret -= serverzone;
ret += LocTimeDiff(ret);
return(ret);
}
/****************************************************************************
put a 8 byte filetime from a time_t
This takes real GMT as input and converts to kludge-GMT
****************************************************************************/
void put_long_date(char *p,time_t t)
{
uint32 tlow,thigh;
double d;
if (t==0) {
SIVAL(p,0,0); SIVAL(p,4,0);
return;
}
/* this converts GMT to kludge-GMT */
t -= LocTimeDiff(t) - serverzone;
d = (double) (t);
d += TIME_FIXUP_CONSTANT;
d *= 1.0e7;
thigh = (uint32)(d * (1.0/(4.0*(double)(1<<30))));
tlow = (uint32)(d - ((double)thigh)*4.0*(double)(1<<30));
SIVAL(p,0,tlow);
SIVAL(p,4,thigh);
}
/****************************************************************************
check if it's a null mtime
****************************************************************************/
BOOL null_mtime(time_t mtime)
{
if (mtime == 0 || mtime == 0xFFFFFFFF || mtime == (time_t)-1)
return(True);
return(False);
}
/*******************************************************************
create a 16 bit dos packed date
********************************************************************/
static uint16 make_dos_date1(time_t unixdate,struct tm *t)
{
uint16 ret=0;
ret = (((unsigned)(t->tm_mon+1)) >> 3) | ((t->tm_year-80) << 1);
ret = ((ret&0xFF)<<8) | (t->tm_mday | (((t->tm_mon+1) & 0x7) << 5));
return(ret);
}
/*******************************************************************
create a 16 bit dos packed time
********************************************************************/
static uint16 make_dos_time1(time_t unixdate,struct tm *t)
{
uint16 ret=0;
ret = ((((unsigned)t->tm_min >> 3)&0x7) | (((unsigned)t->tm_hour) << 3));
ret = ((ret&0xFF)<<8) | ((t->tm_sec/2) | ((t->tm_min & 0x7) << 5));
return(ret);
}
/*******************************************************************
create a 32 bit dos packed date/time from some parameters
This takes a GMT time and returns a packed localtime structure
********************************************************************/
static uint32 make_dos_date(time_t unixdate)
{
struct tm *t;
uint32 ret=0;
t = LocalTime(&unixdate);
if (!t)
return 0xFFFFFFFF;
ret = make_dos_date1(unixdate,t);
ret = ((ret&0xFFFF)<<16) | make_dos_time1(unixdate,t);
return(ret);
}
/*******************************************************************
put a dos date into a buffer (time/date format)
This takes GMT time and puts local time in the buffer
********************************************************************/
void put_dos_date(char *buf,int offset,time_t unixdate)
{
uint32 x = make_dos_date(unixdate);
SIVAL(buf,offset,x);
}
/*******************************************************************
put a dos date into a buffer (date/time format)
This takes GMT time and puts local time in the buffer
********************************************************************/
void put_dos_date2(char *buf,int offset,time_t unixdate)
{
uint32 x = make_dos_date(unixdate);
x = ((x&0xFFFF)<<16) | ((x&0xFFFF0000)>>16);
SIVAL(buf,offset,x);
}
/*******************************************************************
put a dos 32 bit "unix like" date into a buffer. This routine takes
GMT and converts it to LOCAL time before putting it (most SMBs assume
localtime for this sort of date)
********************************************************************/
void put_dos_date3(char *buf,int offset,time_t unixdate)
{
if (!null_mtime(unixdate))
unixdate -= TimeDiff(unixdate);
SIVAL(buf,offset,unixdate);
}
/*******************************************************************
interpret a 32 bit dos packed date/time to some parameters
********************************************************************/
static void interpret_dos_date(uint32 date,int *year,int *month,int *day,int *hour,int *minute,int *second)
{
uint32 p0,p1,p2,p3;
p0=date&0xFF; p1=((date&0xFF00)>>8)&0xFF;
p2=((date&0xFF0000)>>16)&0xFF; p3=((date&0xFF000000)>>24)&0xFF;
*second = 2*(p0 & 0x1F);
*minute = ((p0>>5)&0xFF) + ((p1&0x7)<<3);
*hour = (p1>>3)&0xFF;
*day = (p2&0x1F);
*month = ((p2>>5)&0xFF) + ((p3&0x1)<<3) - 1;
*year = ((p3>>1)&0xFF) + 80;
}
/*******************************************************************
create a unix date (int GMT) from a dos date (which is actually in
localtime)
********************************************************************/
time_t make_unix_date(void *date_ptr)
{
uint32 dos_date=0;
struct tm t;
time_t ret;
dos_date = IVAL(date_ptr,0);
if (dos_date == 0) return(0);
interpret_dos_date(dos_date,&t.tm_year,&t.tm_mon,
&t.tm_mday,&t.tm_hour,&t.tm_min,&t.tm_sec);
t.tm_isdst = -1;
/* mktime() also does the local to GMT time conversion for us */
ret = mktime(&t);
return(ret);
}
/*******************************************************************
like make_unix_date() but the words are reversed
********************************************************************/
time_t make_unix_date2(void *date_ptr)
{
uint32 x,x2;
x = IVAL(date_ptr,0);
x2 = ((x&0xFFFF)<<16) | ((x&0xFFFF0000)>>16);
SIVAL(&x,0,x2);
return(make_unix_date((void *)&x));
}
/*******************************************************************
create a unix GMT date from a dos date in 32 bit "unix like" format
these generally arrive as localtimes, with corresponding DST
******************************************************************/
time_t make_unix_date3(void *date_ptr)
{
time_t t = IVAL(date_ptr,0);
if (!null_mtime(t))
t += LocTimeDiff(t);
return(t);
}
/****************************************************************************
return the date and time as a string
****************************************************************************/
char *timestring(void )
{
static fstring TimeBuf;
time_t t = time(NULL);
struct tm *tm = LocalTime(&t);
if (!tm)
slprintf(TimeBuf,sizeof(TimeBuf)-1,"%ld seconds since the Epoch",(long)t);
else
#ifdef NO_STRFTIME
fstrcpy(TimeBuf, asctime(tm));
#elif defined(CLIX) || defined(CONVEX)
strftime(TimeBuf,100,"%Y/%m/%d %I:%M:%S %p",tm);
#elif defined(AMPM)
strftime(TimeBuf,100,"%Y/%m/%d %r",tm);
#elif defined(TZ_TIME)
{
int zone = TimeDiff(t);
int absZoneMinutes = (zone<0 ? -zone : zone) / 60;
#if defined(NEXT3) || defined(NEXT4) /* fixup for limited strftime -- Rex 980928 */
size_t len = strftime(TimeBuf,sizeof(TimeBuf)-6,"%Y/%m/%d %H:%M:%S",tm);
#else
size_t len = strftime(TimeBuf,sizeof(TimeBuf)-6,"%Y/%m/%d %T",tm);
#endif
slprintf(TimeBuf+len, sizeof(TimeBuf) - len - 1, " %c%02d%02d",
zone<0?'+':'-',absZoneMinutes/60,absZoneMinutes%60);
}
#elif defined(NEXT3) || defined(NEXT4)
strftime(TimeBuf,100,"%Y/%m/%d %H:%M:%S",tm);
#else
strftime(TimeBuf,100,"%Y/%m/%d %T",tm);
#endif
return(TimeBuf);
}
/****************************************************************************
return the best approximation to a 'create time' under UNIX from a stat
structure.
****************************************************************************/
time_t get_create_time(struct stat *st,BOOL fake_dirs)
{
time_t ret, ret1;
if(S_ISDIR(st->st_mode) && fake_dirs)
return (time_t)315493200L; /* 1/1/1980 */
ret = MIN(st->st_ctime, st->st_mtime);
ret1 = MIN(ret, st->st_atime);
if(ret1 != (time_t)0)
return ret1;
/*
* One of ctime, mtime or atime was zero (probably atime).
* Just return MIN(ctime, mtime).
*/
return ret;
}
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.