time.c

samba-3.0.22.tar.gz 编译smb服务器的源码

/* 
   Unix SMB/CIFS implementation.
   time handling functions
   Copyright (C) Andrew Tridgell 		1992-1998
   Copyright (C) Stefan (metze) Metzmacher	2002   
   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 <[e-mail]>
  in May 1996 
  */

int extra_time_offset = 0;

#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

void get_nttime_max(NTTIME *t)
{
	/* FIXME: This is incorrect */
	unix_to_nt_time(t, get_time_t_max());
}

/*******************************************************************
 External access to time_t_min and time_t_max.
********************************************************************/

time_t get_time_t_max(void)
{
	return TIME_T_MAX;
}

/*******************************************************************
 A gettimeofday wrapper.
********************************************************************/

void GetTimeOfDay(struct timeval *tval)
{
#ifdef HAVE_GETTIMEOFDAY_TZ
	gettimeofday(tval,NULL);
#else
	gettimeofday(tval);
#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.
******************************************************************/

int get_time_zone(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) + 60*extra_time_offset;
}

/*******************************************************************
 Accessor function for the server time zone offset.
 set_server_zone_offset() must have been called first.
******************************************************************/

static int server_zone_offset;

int get_server_zone_offset(void)
{
	return server_zone_offset;
}

/*******************************************************************
 Initialize the server time zone offset. Called when a client connects.
******************************************************************/

int set_server_zone_offset(time_t t)
{
	server_zone_offset = get_time_zone(t);
	return server_zone_offset;
}

/*******************************************************************
 Re-read the smb serverzone value.
******************************************************************/

static struct timeval start_time_hires;

void TimeInit(void)
{
	set_server_zone_offset(time(NULL));

	DEBUG(4,("TimeInit: Serverzone is %d\n", server_zone_offset));

	/* Save the start time of this process. */
	if (start_time_hires.tv_sec == 0 && start_time_hires.tv_usec == 0) {
		GetTimeOfDay(&start_time_hires);
	}
}

/**********************************************************************
 Return a timeval struct of the uptime of this process. As TimeInit is
 done before a daemon fork then this is the start time from the parent
 daemon start. JRA.
***********************************************************************/

void get_process_uptime(struct timeval *ret_time)
{
	struct timeval time_now_hires;

	GetTimeOfDay(&time_now_hires);
	ret_time->tv_sec = time_now_hires.tv_sec - start_time_hires.tv_sec;
	ret_time->tv_usec = time_now_hires.tv_usec - start_time_hires.tv_usec;
	if (time_now_hires.tv_usec < start_time_hires.tv_usec) {
		ret_time->tv_sec -= 1;
		ret_time->tv_usec = 1000000 + (time_now_hires.tv_usec - start_time_hires.tv_usec);
	} else {
		ret_time->tv_usec = time_now_hires.tv_usec - start_time_hires.tv_usec;
	}
}

#if 0
/****************************************************************************
 Return the UTC offset in seconds west of UTC, adjusted for extra time offset.
**************************************************************************/

int TimeDiff(time_t t)
{
	return get_time_zone(t);
}
#endif

#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"

 An 8 byte value of 0xffffffffffffffff will be returned as (time_t)0.

 Returns GMT.
****************************************************************************/

time_t nt_time_to_unix(NTTIME *nt)
{
	double d;
	time_t ret;
	/* 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;

	if (nt->high == 0 || (nt->high == 0xffffffff && nt->low == 0xffffffff)) {
		return(0);
	}

	d = ((double)nt->high)*4.0*(double)(1<<30);
	d += (nt->low&0xFFF00000);
	d *= 1.0e-7;
 
	/* now adjust by 369 years to make the secs since 1970 */
	d -= TIME_FIXUP_CONSTANT;

	if (d <= l_time_min) {
		return (l_time_min);
	}

	if (d >= l_time_max) {
		return (l_time_max);
	}

	ret = (time_t)(d+0.5);
	return(ret);
}

/****************************************************************************
 Convert a NTTIME structure to a time_t.
 It's originally in "100ns units".

 This is an absolute version of the one above.
 By absolute I mean, it doesn't adjust from 1/1/1601 to 1/1/1970
 if the NTTIME was 5 seconds, the time_t is 5 seconds. JFM
****************************************************************************/

time_t nt_time_to_unix_abs(NTTIME *nt)
{
	double d;
	time_t ret;
	/* 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;

	if (nt->high == 0) {
		return(0);
	}

	if (nt->high==0x80000000 && nt->low==0) {
		return (time_t)-1;
	}

	/* reverse the time */
	/* it's a negative value, turn it to positive */
	nt->high=~nt->high;
	nt->low=~nt->low;

	d = ((double)nt->high)*4.0*(double)(1<<30);
	d += (nt->low&0xFFF00000);
	d *= 1.0e-7;
  
	if (!(l_time_min <= d && d <= l_time_max)) {
		return(0);
	}

	ret = (time_t)(d+0.5);

	return(ret);
}

/****************************************************************************
 Interprets an nt time into a unix time_t.
 Differs from nt_time_to_unix in that an 8 byte value of 0xffffffffffffffff
 will be returned as (time_t)-1, whereas nt_time_to_unix returns 0 in this case.
****************************************************************************/

time_t interpret_long_date(char *p)
{
	NTTIME nt;
	nt.low = IVAL(p,0);
	nt.high = IVAL(p,4);
	if (nt.low == 0xFFFFFFFF && nt.high == 0xFFFFFFFF) {
		return (time_t)-1;
	}
	return nt_time_to_unix(&nt);
}

/****************************************************************************
 Put a 8 byte filetime from a time_t. Uses GMT.
****************************************************************************/

void unix_to_nt_time(NTTIME *nt, time_t t)
{
	double d;

	if (t==0) {
		nt->low = 0;
		nt->high = 0;
		return;
	}
	if (t == TIME_T_MAX) {
		nt->low = 0xffffffff;
		nt->high = 0x7fffffff;
		return;
	}		
	if (t == (time_t)-1) {
		nt->low = 0xffffffff;
		nt->high = 0xffffffff;
		return;
	}		

	d = (double)(t);
	d += TIME_FIXUP_CONSTANT;
	d *= 1.0e7;

	nt->high = (uint32)(d * (1.0/(4.0*(double)(1<<30))));
	nt->low  = (uint32)(d - ((double)nt->high)*4.0*(double)(1<<30));
}

/****************************************************************************
 Convert a time_t to a NTTIME structure

 This is an absolute version of the one above.
 By absolute I mean, it doesn't adjust from 1/1/1970 to 1/1/1601
 If the nttime_t was 5 seconds, the NTTIME is 5 seconds. JFM
****************************************************************************/

void unix_to_nt_time_abs(NTTIME *nt, time_t t)
{
	double d;

	if (t==0) {
		nt->low = 0;
		nt->high = 0;
		return;
	}

	if (t == TIME_T_MAX) {
		nt->low = 0xffffffff;
		nt->high = 0x7fffffff;
		return;
	}
		
	if (t == (time_t)-1) {
		/* that's what NT uses for infinite */
		nt->low = 0x0;
		nt->high = 0x80000000;
		return;
	}		

	d = (double)(t);
	d *= 1.0e7;

	nt->high = (uint32)(d * (1.0/(4.0*(double)(1<<30))));
	nt->low  = (uint32)(d - ((double)nt->high)*4.0*(double)(1<<30));

	/* convert to a negative value */
	nt->high=~nt->high;
	nt->low=~nt->low;
}

/****************************************************************************
 Take a Unix time and convert to an NTTIME structure and place in buffer 
 pointed to by p.
****************************************************************************/

void put_long_date(char *p, time_t t)
{
	NTTIME nt;
	unix_to_nt_time(&nt, t);
	SIVAL(p, 0, nt.low);
	SIVAL(p, 4, nt.high);
}

/****************************************************************************
 Check if it's a null mtime.
****************************************************************************/

BOOL null_mtime(time_t mtime)
{
	if (mtime == 0 || mtime == (time_t)0xFFFFFFFF || mtime == (time_t)-1)
		return(True);
	return(False);
}

/*******************************************************************
 Create a 16 bit dos packed date.
********************************************************************/

static uint16 make_dos_date1(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(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, int zone_offset)
{
	struct tm *t;
	uint32 ret=0;

	if (unixdate == 0) {
		return 0;
	}

	unixdate -= zone_offset;
	t = gmtime(&unixdate);
	if (!t) {
		return 0xFFFFFFFF;
	}

	ret = make_dos_date1(t);
	ret = ((ret&0xFFFF)<<16) | make_dos_time1(t);

	return(ret);
}

/*******************************************************************
 Put a dos date into a buffer (time/date format).
 This takes GMT time and puts local time in the buffer.
********************************************************************/

static void put_dos_date(char *buf,int offset,time_t unixdate, int zone_offset)
{
	uint32 x = make_dos_date(unixdate, zone_offset);
	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.
********************************************************************/

static void put_dos_date2(char *buf,int offset,time_t unixdate, int zone_offset)
{
	uint32 x = make_dos_date(unixdate, zone_offset);
	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)
********************************************************************/

static void put_dos_date3(char *buf,int offset,time_t unixdate, int zone_offset)
{
	if (!null_mtime(unixdate)) {
		unixdate -= zone_offset;
	}
	SIVAL(buf,offset,unixdate);
}

/*******************************************************************
 Interpret a 32 bit dos packed date/time to some parameters.