Release 1.5.29.
[wine] / dlls / ntdll / time.c
1 /*
2  * Nt time functions.
3  *
4  * RtlTimeToTimeFields, RtlTimeFieldsToTime and defines are taken from ReactOS and
5  * adapted to wine with special permissions of the author. This code is
6  * Copyright 2002 Rex Jolliff (rex@lvcablemodem.com)
7  *
8  * Copyright 1999 Juergen Schmied
9  * Copyright 2007 Dmitry Timoshkov
10  *
11  * This library is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU Lesser General Public
13  * License as published by the Free Software Foundation; either
14  * version 2.1 of the License, or (at your option) any later version.
15  *
16  * This library is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  * Lesser General Public License for more details.
20  *
21  * You should have received a copy of the GNU Lesser General Public
22  * License along with this library; if not, write to the Free Software
23  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
24  */
25
26 #include "config.h"
27 #include "wine/port.h"
28
29 #include <stdarg.h>
30 #include <stdlib.h>
31 #include <errno.h>
32 #include <string.h>
33 #include <limits.h>
34 #include <time.h>
35 #ifdef HAVE_SYS_TIME_H
36 # include <sys/time.h>
37 #endif
38 #ifdef HAVE_UNISTD_H
39 # include <unistd.h>
40 #endif
41 #ifdef __APPLE__
42 # include <mach/mach_time.h>
43 #endif
44
45 #define NONAMELESSUNION
46 #define NONAMELESSSTRUCT
47 #include "ntstatus.h"
48 #define WIN32_NO_STATUS
49 #include "windef.h"
50 #include "winternl.h"
51 #include "wine/unicode.h"
52 #include "wine/debug.h"
53 #include "ntdll_misc.h"
54
55 WINE_DEFAULT_DEBUG_CHANNEL(ntdll);
56
57 static int init_tz_info(RTL_TIME_ZONE_INFORMATION *tzi);
58
59 static RTL_CRITICAL_SECTION TIME_tz_section;
60 static RTL_CRITICAL_SECTION_DEBUG critsect_debug =
61 {
62     0, 0, &TIME_tz_section,
63     { &critsect_debug.ProcessLocksList, &critsect_debug.ProcessLocksList },
64       0, 0, { (DWORD_PTR)(__FILE__ ": TIME_tz_section") }
65 };
66 static RTL_CRITICAL_SECTION TIME_tz_section = { &critsect_debug, -1, 0, 0, 0, 0 };
67
68 #define TICKSPERSEC        10000000
69 #define TICKSPERMSEC       10000
70 #define SECSPERDAY         86400
71 #define SECSPERHOUR        3600
72 #define SECSPERMIN         60
73 #define MINSPERHOUR        60
74 #define HOURSPERDAY        24
75 #define EPOCHWEEKDAY       1  /* Jan 1, 1601 was Monday */
76 #define DAYSPERWEEK        7
77 #define EPOCHYEAR          1601
78 #define DAYSPERNORMALYEAR  365
79 #define DAYSPERLEAPYEAR    366
80 #define MONSPERYEAR        12
81 #define DAYSPERQUADRICENTENNIUM (365 * 400 + 97)
82 #define DAYSPERNORMALCENTURY (365 * 100 + 24)
83 #define DAYSPERNORMALQUADRENNIUM (365 * 4 + 1)
84
85 /* 1601 to 1970 is 369 years plus 89 leap days */
86 #define SECS_1601_TO_1970  ((369 * 365 + 89) * (ULONGLONG)SECSPERDAY)
87 #define TICKS_1601_TO_1970 (SECS_1601_TO_1970 * TICKSPERSEC)
88 /* 1601 to 1980 is 379 years plus 91 leap days */
89 #define SECS_1601_TO_1980  ((379 * 365 + 91) * (ULONGLONG)SECSPERDAY)
90 #define TICKS_1601_TO_1980 (SECS_1601_TO_1980 * TICKSPERSEC)
91
92
93 static const int MonthLengths[2][MONSPERYEAR] =
94 {
95         { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
96         { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
97 };
98
99 static inline int IsLeapYear(int Year)
100 {
101         return Year % 4 == 0 && (Year % 100 != 0 || Year % 400 == 0) ? 1 : 0;
102 }
103
104 /* return a monotonic time counter, in Win32 ticks */
105 static ULONGLONG monotonic_counter(void)
106 {
107     struct timeval now;
108
109 #ifdef HAVE_CLOCK_GETTIME
110     struct timespec ts;
111 #ifdef CLOCK_MONOTONIC_RAW
112     if (!clock_gettime( CLOCK_MONOTONIC_RAW, &ts ))
113         return ts.tv_sec * (ULONGLONG)TICKSPERSEC + ts.tv_nsec / 100;
114 #endif
115     if (!clock_gettime( CLOCK_MONOTONIC, &ts ))
116         return ts.tv_sec * (ULONGLONG)TICKSPERSEC + ts.tv_nsec / 100;
117 #elif defined(__APPLE__)
118     static mach_timebase_info_data_t timebase;
119
120     if (!timebase.denom) mach_timebase_info( &timebase );
121     return mach_absolute_time() * timebase.numer / timebase.denom / 100;
122 #endif
123
124     gettimeofday( &now, 0 );
125     return now.tv_sec * (ULONGLONG)TICKSPERSEC + now.tv_usec * 10 + TICKS_1601_TO_1970 - server_start_time;
126 }
127
128 /******************************************************************************
129  *       RtlTimeToTimeFields [NTDLL.@]
130  *
131  * Convert a time into a TIME_FIELDS structure.
132  *
133  * PARAMS
134  *   liTime     [I] Time to convert.
135  *   TimeFields [O] Destination for the converted time.
136  *
137  * RETURNS
138  *   Nothing.
139  */
140 VOID WINAPI RtlTimeToTimeFields(
141         const LARGE_INTEGER *liTime,
142         PTIME_FIELDS TimeFields)
143 {
144         int SecondsInDay;
145         long int cleaps, years, yearday, months;
146         long int Days;
147         LONGLONG Time;
148
149         /* Extract millisecond from time and convert time into seconds */
150         TimeFields->Milliseconds =
151             (CSHORT) (( liTime->QuadPart % TICKSPERSEC) / TICKSPERMSEC);
152         Time = liTime->QuadPart / TICKSPERSEC;
153
154         /* The native version of RtlTimeToTimeFields does not take leap seconds
155          * into account */
156
157         /* Split the time into days and seconds within the day */
158         Days = Time / SECSPERDAY;
159         SecondsInDay = Time % SECSPERDAY;
160
161         /* compute time of day */
162         TimeFields->Hour = (CSHORT) (SecondsInDay / SECSPERHOUR);
163         SecondsInDay = SecondsInDay % SECSPERHOUR;
164         TimeFields->Minute = (CSHORT) (SecondsInDay / SECSPERMIN);
165         TimeFields->Second = (CSHORT) (SecondsInDay % SECSPERMIN);
166
167         /* compute day of week */
168         TimeFields->Weekday = (CSHORT) ((EPOCHWEEKDAY + Days) % DAYSPERWEEK);
169
170         /* compute year, month and day of month. */
171         cleaps=( 3 * ((4 * Days + 1227) / DAYSPERQUADRICENTENNIUM) + 3 ) / 4;
172         Days += 28188 + cleaps;
173         years = (20 * Days - 2442) / (5 * DAYSPERNORMALQUADRENNIUM);
174         yearday = Days - (years * DAYSPERNORMALQUADRENNIUM)/4;
175         months = (64 * yearday) / 1959;
176         /* the result is based on a year starting on March.
177          * To convert take 12 from Januari and Februari and
178          * increase the year by one. */
179         if( months < 14 ) {
180             TimeFields->Month = months - 1;
181             TimeFields->Year = years + 1524;
182         } else {
183             TimeFields->Month = months - 13;
184             TimeFields->Year = years + 1525;
185         }
186         /* calculation of day of month is based on the wonderful
187          * sequence of INT( n * 30.6): it reproduces the 
188          * 31-30-31-30-31-31 month lengths exactly for small n's */
189         TimeFields->Day = yearday - (1959 * months) / 64 ;
190         return;
191 }
192
193 /******************************************************************************
194  *       RtlTimeFieldsToTime [NTDLL.@]
195  *
196  * Convert a TIME_FIELDS structure into a time.
197  *
198  * PARAMS
199  *   ftTimeFields [I] TIME_FIELDS structure to convert.
200  *   Time         [O] Destination for the converted time.
201  *
202  * RETURNS
203  *   Success: TRUE.
204  *   Failure: FALSE.
205  */
206 BOOLEAN WINAPI RtlTimeFieldsToTime(
207         PTIME_FIELDS tfTimeFields,
208         PLARGE_INTEGER Time)
209 {
210         int month, year, cleaps, day;
211
212         /* FIXME: normalize the TIME_FIELDS structure here */
213         /* No, native just returns 0 (error) if the fields are not */
214         if( tfTimeFields->Milliseconds< 0 || tfTimeFields->Milliseconds > 999 ||
215                 tfTimeFields->Second < 0 || tfTimeFields->Second > 59 ||
216                 tfTimeFields->Minute < 0 || tfTimeFields->Minute > 59 ||
217                 tfTimeFields->Hour < 0 || tfTimeFields->Hour > 23 ||
218                 tfTimeFields->Month < 1 || tfTimeFields->Month > 12 ||
219                 tfTimeFields->Day < 1 ||
220                 tfTimeFields->Day > MonthLengths
221                     [ tfTimeFields->Month ==2 || IsLeapYear(tfTimeFields->Year)]
222                     [ tfTimeFields->Month - 1] ||
223                 tfTimeFields->Year < 1601 )
224             return FALSE;
225
226         /* now calculate a day count from the date
227          * First start counting years from March. This way the leap days
228          * are added at the end of the year, not somewhere in the middle.
229          * Formula's become so much less complicate that way.
230          * To convert: add 12 to the month numbers of Jan and Feb, and 
231          * take 1 from the year */
232         if(tfTimeFields->Month < 3) {
233             month = tfTimeFields->Month + 13;
234             year = tfTimeFields->Year - 1;
235         } else {
236             month = tfTimeFields->Month + 1;
237             year = tfTimeFields->Year;
238         }
239         cleaps = (3 * (year / 100) + 3) / 4;   /* nr of "century leap years"*/
240         day =  (36525 * year) / 100 - cleaps + /* year * dayperyr, corrected */
241                  (1959 * month) / 64 +         /* months * daypermonth */
242                  tfTimeFields->Day -          /* day of the month */
243                  584817 ;                      /* zero that on 1601-01-01 */
244         /* done */
245         
246         Time->QuadPart = (((((LONGLONG) day * HOURSPERDAY +
247             tfTimeFields->Hour) * MINSPERHOUR +
248             tfTimeFields->Minute) * SECSPERMIN +
249             tfTimeFields->Second ) * 1000 +
250             tfTimeFields->Milliseconds ) * TICKSPERMSEC;
251
252         return TRUE;
253 }
254
255 /***********************************************************************
256  *       TIME_GetBias [internal]
257  *
258  * Helper function calculates delta local time from UTC. 
259  *
260  * PARAMS
261  *   utc [I] The current utc time.
262  *   pdaylight [I] Local daylight.
263  *
264  * RETURNS
265  *   The bias for the current timezone.
266  */
267 static LONG TIME_GetBias(void)
268 {
269     static time_t last_utc;
270     static LONG last_bias;
271     LONG ret;
272     time_t utc;
273
274     utc = time( NULL );
275
276     RtlEnterCriticalSection( &TIME_tz_section );
277     if (utc != last_utc)
278     {
279         RTL_TIME_ZONE_INFORMATION tzi;
280         int is_dst = init_tz_info( &tzi );
281
282         last_utc = utc;
283         last_bias = tzi.Bias;
284         last_bias += is_dst ? tzi.DaylightBias : tzi.StandardBias;
285         last_bias *= SECSPERMIN;
286     }
287
288     ret = last_bias;
289
290     RtlLeaveCriticalSection( &TIME_tz_section );
291     return ret;
292 }
293
294 /******************************************************************************
295  *        RtlLocalTimeToSystemTime [NTDLL.@]
296  *
297  * Convert a local time into system time.
298  *
299  * PARAMS
300  *   LocalTime  [I] Local time to convert.
301  *   SystemTime [O] Destination for the converted time.
302  *
303  * RETURNS
304  *   Success: STATUS_SUCCESS.
305  *   Failure: An NTSTATUS error code indicating the problem.
306  */
307 NTSTATUS WINAPI RtlLocalTimeToSystemTime( const LARGE_INTEGER *LocalTime,
308                                           PLARGE_INTEGER SystemTime)
309 {
310     LONG bias;
311
312     TRACE("(%p, %p)\n", LocalTime, SystemTime);
313
314     bias = TIME_GetBias();
315     SystemTime->QuadPart = LocalTime->QuadPart + bias * (LONGLONG)TICKSPERSEC;
316     return STATUS_SUCCESS;
317 }
318
319 /******************************************************************************
320  *       RtlSystemTimeToLocalTime [NTDLL.@]
321  *
322  * Convert a system time into a local time.
323  *
324  * PARAMS
325  *   SystemTime [I] System time to convert.
326  *   LocalTime  [O] Destination for the converted time.
327  *
328  * RETURNS
329  *   Success: STATUS_SUCCESS.
330  *   Failure: An NTSTATUS error code indicating the problem.
331  */
332 NTSTATUS WINAPI RtlSystemTimeToLocalTime( const LARGE_INTEGER *SystemTime,
333                                           PLARGE_INTEGER LocalTime )
334 {
335     LONG bias;
336
337     TRACE("(%p, %p)\n", SystemTime, LocalTime);
338
339     bias = TIME_GetBias();
340     LocalTime->QuadPart = SystemTime->QuadPart - bias * (LONGLONG)TICKSPERSEC;
341     return STATUS_SUCCESS;
342 }
343
344 /******************************************************************************
345  *       RtlTimeToSecondsSince1970 [NTDLL.@]
346  *
347  * Convert a time into a count of seconds since 1970.
348  *
349  * PARAMS
350  *   Time    [I] Time to convert.
351  *   Seconds [O] Destination for the converted time.
352  *
353  * RETURNS
354  *   Success: TRUE.
355  *   Failure: FALSE, if the resulting value will not fit in a DWORD.
356  */
357 BOOLEAN WINAPI RtlTimeToSecondsSince1970( const LARGE_INTEGER *Time, LPDWORD Seconds )
358 {
359     ULONGLONG tmp = Time->QuadPart / TICKSPERSEC - SECS_1601_TO_1970;
360     if (tmp > 0xffffffff) return FALSE;
361     *Seconds = tmp;
362     return TRUE;
363 }
364
365 /******************************************************************************
366  *       RtlTimeToSecondsSince1980 [NTDLL.@]
367  *
368  * Convert a time into a count of seconds since 1980.
369  *
370  * PARAMS
371  *   Time    [I] Time to convert.
372  *   Seconds [O] Destination for the converted time.
373  *
374  * RETURNS
375  *   Success: TRUE.
376  *   Failure: FALSE, if the resulting value will not fit in a DWORD.
377  */
378 BOOLEAN WINAPI RtlTimeToSecondsSince1980( const LARGE_INTEGER *Time, LPDWORD Seconds )
379 {
380     ULONGLONG tmp = Time->QuadPart / TICKSPERSEC - SECS_1601_TO_1980;
381     if (tmp > 0xffffffff) return FALSE;
382     *Seconds = tmp;
383     return TRUE;
384 }
385
386 /******************************************************************************
387  *       RtlSecondsSince1970ToTime [NTDLL.@]
388  *
389  * Convert a count of seconds since 1970 to a time.
390  *
391  * PARAMS
392  *   Seconds [I] Time to convert.
393  *   Time    [O] Destination for the converted time.
394  *
395  * RETURNS
396  *   Nothing.
397  */
398 void WINAPI RtlSecondsSince1970ToTime( DWORD Seconds, LARGE_INTEGER *Time )
399 {
400     Time->QuadPart = Seconds * (ULONGLONG)TICKSPERSEC + TICKS_1601_TO_1970;
401 }
402
403 /******************************************************************************
404  *       RtlSecondsSince1980ToTime [NTDLL.@]
405  *
406  * Convert a count of seconds since 1980 to a time.
407  *
408  * PARAMS
409  *   Seconds [I] Time to convert.
410  *   Time    [O] Destination for the converted time.
411  *
412  * RETURNS
413  *   Nothing.
414  */
415 void WINAPI RtlSecondsSince1980ToTime( DWORD Seconds, LARGE_INTEGER *Time )
416 {
417     Time->QuadPart = Seconds * (ULONGLONG)TICKSPERSEC + TICKS_1601_TO_1980;
418 }
419
420 /******************************************************************************
421  *       RtlTimeToElapsedTimeFields [NTDLL.@]
422  *
423  * Convert a time to a count of elapsed seconds.
424  *
425  * PARAMS
426  *   Time       [I] Time to convert.
427  *   TimeFields [O] Destination for the converted time.
428  *
429  * RETURNS
430  *   Nothing.
431  */
432 void WINAPI RtlTimeToElapsedTimeFields( const LARGE_INTEGER *Time, PTIME_FIELDS TimeFields )
433 {
434     LONGLONG time;
435     INT rem;
436
437     time = Time->QuadPart / TICKSPERSEC;
438     TimeFields->Milliseconds = (Time->QuadPart % TICKSPERSEC) / TICKSPERMSEC;
439
440     /* time is now in seconds */
441     TimeFields->Year  = 0;
442     TimeFields->Month = 0;
443     TimeFields->Day   = time / SECSPERDAY;
444
445     /* rem is now the remaining seconds in the last day */
446     rem = time % SECSPERDAY;
447     TimeFields->Second = rem % 60;
448     rem /= 60;
449     TimeFields->Minute = rem % 60;
450     TimeFields->Hour = rem / 60;
451 }
452
453 /***********************************************************************
454  *       NtQuerySystemTime [NTDLL.@]
455  *       ZwQuerySystemTime [NTDLL.@]
456  *
457  * Get the current system time.
458  *
459  * PARAMS
460  *   Time [O] Destination for the current system time.
461  *
462  * RETURNS
463  *   Success: STATUS_SUCCESS.
464  *   Failure: An NTSTATUS error code indicating the problem.
465  */
466 NTSTATUS WINAPI NtQuerySystemTime( PLARGE_INTEGER Time )
467 {
468     struct timeval now;
469
470     gettimeofday( &now, 0 );
471     Time->QuadPart = now.tv_sec * (ULONGLONG)TICKSPERSEC + TICKS_1601_TO_1970;
472     Time->QuadPart += now.tv_usec * 10;
473     return STATUS_SUCCESS;
474 }
475
476 /******************************************************************************
477  *  NtQueryPerformanceCounter   [NTDLL.@]
478  */
479 NTSTATUS WINAPI NtQueryPerformanceCounter( LARGE_INTEGER *counter, LARGE_INTEGER *frequency )
480 {
481     if (!counter) return STATUS_ACCESS_VIOLATION;
482
483     counter->QuadPart = monotonic_counter();
484     if (frequency) frequency->QuadPart = TICKSPERSEC;
485     return STATUS_SUCCESS;
486 }
487
488
489 /******************************************************************************
490  * NtGetTickCount   (NTDLL.@)
491  * ZwGetTickCount   (NTDLL.@)
492  */
493 ULONG WINAPI NtGetTickCount(void)
494 {
495     return monotonic_counter() / TICKSPERMSEC;
496 }
497
498 /* calculate the mday of dst change date, so that for instance Sun 5 Oct 2007
499  * (last Sunday in October of 2007) becomes Sun Oct 28 2007
500  *
501  * Note: year, day and month must be in unix format.
502  */
503 static int weekday_to_mday(int year, int day, int mon, int day_of_week)
504 {
505     struct tm date;
506     time_t tmp;
507     int wday, mday;
508
509     /* find first day in the month matching week day of the date */
510     memset(&date, 0, sizeof(date));
511     date.tm_year = year;
512     date.tm_mon = mon;
513     date.tm_mday = -1;
514     date.tm_wday = -1;
515     do
516     {
517         date.tm_mday++;
518         tmp = mktime(&date);
519     } while (date.tm_wday != day_of_week || date.tm_mon != mon);
520
521     mday = date.tm_mday;
522
523     /* find number of week days in the month matching week day of the date */
524     wday = 1; /* 1 - 1st, ...., 5 - last */
525     while (wday < day)
526     {
527         struct tm *tm;
528
529         date.tm_mday += 7;
530         tmp = mktime(&date);
531         tm = localtime(&tmp);
532         if (tm->tm_mon != mon)
533             break;
534         mday = tm->tm_mday;
535         wday++;
536     }
537
538     return mday;
539 }
540
541 static BOOL match_tz_date(const RTL_SYSTEM_TIME *st, const RTL_SYSTEM_TIME *reg_st)
542 {
543     WORD wDay;
544
545     if (st->wMonth != reg_st->wMonth) return FALSE;
546
547     if (!st->wMonth) return TRUE; /* no transition dates */
548
549     wDay = reg_st->wDay;
550     if (!reg_st->wYear) /* date in a day-of-week format */
551         wDay = weekday_to_mday(st->wYear - 1900, reg_st->wDay, reg_st->wMonth - 1, reg_st->wDayOfWeek);
552
553     if (st->wDay != wDay ||
554         st->wHour != reg_st->wHour ||
555         st->wMinute != reg_st->wMinute ||
556         st->wSecond != reg_st->wSecond ||
557         st->wMilliseconds != reg_st->wMilliseconds) return FALSE;
558
559     return TRUE;
560 }
561
562 static BOOL match_tz_info(const RTL_TIME_ZONE_INFORMATION *tzi, const RTL_TIME_ZONE_INFORMATION *reg_tzi)
563 {
564     if (tzi->Bias == reg_tzi->Bias &&
565         match_tz_date(&tzi->StandardDate, &reg_tzi->StandardDate) &&
566         match_tz_date(&tzi->DaylightDate, &reg_tzi->DaylightDate))
567         return TRUE;
568
569     return FALSE;
570 }
571
572 static BOOL reg_query_value(HKEY hkey, LPCWSTR name, DWORD type, void *data, DWORD count)
573 {
574     UNICODE_STRING nameW;
575     char buf[256];
576     KEY_VALUE_PARTIAL_INFORMATION *info = (KEY_VALUE_PARTIAL_INFORMATION *)buf;
577
578     if (count > sizeof(buf) - sizeof(KEY_VALUE_PARTIAL_INFORMATION))
579         return FALSE;
580
581     RtlInitUnicodeString(&nameW, name);
582
583     if (NtQueryValueKey(hkey, &nameW, KeyValuePartialInformation,
584                         buf, sizeof(buf), &count))
585         return FALSE;
586
587     if (info->Type != type) return FALSE;
588
589     memcpy(data, info->Data, info->DataLength);
590     return TRUE;
591 }
592
593 static void find_reg_tz_info(RTL_TIME_ZONE_INFORMATION *tzi)
594 {
595     static const WCHAR Time_ZonesW[] = { 'M','a','c','h','i','n','e','\\',
596         'S','o','f','t','w','a','r','e','\\',
597         'M','i','c','r','o','s','o','f','t','\\',
598         'W','i','n','d','o','w','s',' ','N','T','\\',
599         'C','u','r','r','e','n','t','V','e','r','s','i','o','n','\\',
600         'T','i','m','e',' ','Z','o','n','e','s',0 };
601     HANDLE hkey;
602     ULONG idx;
603     OBJECT_ATTRIBUTES attr;
604     UNICODE_STRING nameW;
605     WCHAR buf[128];
606
607     attr.Length = sizeof(attr);
608     attr.RootDirectory = 0;
609     attr.ObjectName = &nameW;
610     attr.Attributes = 0;
611     attr.SecurityDescriptor = NULL;
612     attr.SecurityQualityOfService = NULL;
613     RtlInitUnicodeString(&nameW, Time_ZonesW);
614     if (NtOpenKey(&hkey, KEY_READ, &attr))
615     {
616         WARN("Unable to open the time zones key\n");
617         return;
618     }
619
620     idx = 0;
621     nameW.Buffer = buf;
622     nameW.Length = sizeof(buf);
623     nameW.MaximumLength = sizeof(buf);
624
625     while (!RtlpNtEnumerateSubKey(hkey, &nameW, idx++))
626     {
627         static const WCHAR stdW[] = { 'S','t','d',0 };
628         static const WCHAR dltW[] = { 'D','l','t',0 };
629         static const WCHAR tziW[] = { 'T','Z','I',0 };
630         RTL_TIME_ZONE_INFORMATION reg_tzi;
631         HANDLE hSubkey;
632         struct tz_reg_data
633         {
634             LONG bias;
635             LONG std_bias;
636             LONG dlt_bias;
637             RTL_SYSTEM_TIME std_date;
638             RTL_SYSTEM_TIME dlt_date;
639         } tz_data;
640
641         attr.Length = sizeof(attr);
642         attr.RootDirectory = hkey;
643         attr.ObjectName = &nameW;
644         attr.Attributes = 0;
645         attr.SecurityDescriptor = NULL;
646         attr.SecurityQualityOfService = NULL;
647         if (NtOpenKey(&hSubkey, KEY_READ, &attr))
648         {
649             WARN("Unable to open subkey %s\n", debugstr_wn(nameW.Buffer, nameW.Length/sizeof(WCHAR)));
650             continue;
651         }
652
653 #define get_value(hkey, name, type, data, len) \
654     if (!reg_query_value(hkey, name, type, data, len)) \
655     { \
656         WARN("can't read data from %s\n", debugstr_w(name)); \
657         NtClose(hkey); \
658         continue; \
659     }
660
661         get_value(hSubkey, stdW, REG_SZ, reg_tzi.StandardName, sizeof(reg_tzi.StandardName));
662         get_value(hSubkey, dltW, REG_SZ, reg_tzi.DaylightName, sizeof(reg_tzi.DaylightName));
663         get_value(hSubkey, tziW, REG_BINARY, &tz_data, sizeof(tz_data));
664
665 #undef get_value
666
667         reg_tzi.Bias = tz_data.bias;
668         reg_tzi.StandardBias = tz_data.std_bias;
669         reg_tzi.DaylightBias = tz_data.dlt_bias;
670         reg_tzi.StandardDate = tz_data.std_date;
671         reg_tzi.DaylightDate = tz_data.dlt_date;
672
673         TRACE("%s: bias %d\n", debugstr_wn(nameW.Buffer, nameW.Length/sizeof(WCHAR)), reg_tzi.Bias);
674         TRACE("std (d/m/y): %u/%02u/%04u day of week %u %u:%02u:%02u.%03u bias %d\n",
675             reg_tzi.StandardDate.wDay, reg_tzi.StandardDate.wMonth,
676             reg_tzi.StandardDate.wYear, reg_tzi.StandardDate.wDayOfWeek,
677             reg_tzi.StandardDate.wHour, reg_tzi.StandardDate.wMinute,
678             reg_tzi.StandardDate.wSecond, reg_tzi.StandardDate.wMilliseconds,
679             reg_tzi.StandardBias);
680         TRACE("dst (d/m/y): %u/%02u/%04u day of week %u %u:%02u:%02u.%03u bias %d\n",
681             reg_tzi.DaylightDate.wDay, reg_tzi.DaylightDate.wMonth,
682             reg_tzi.DaylightDate.wYear, reg_tzi.DaylightDate.wDayOfWeek,
683             reg_tzi.DaylightDate.wHour, reg_tzi.DaylightDate.wMinute,
684             reg_tzi.DaylightDate.wSecond, reg_tzi.DaylightDate.wMilliseconds,
685             reg_tzi.DaylightBias);
686
687         NtClose(hSubkey);
688
689         if (match_tz_info(tzi, &reg_tzi))
690         {
691             *tzi = reg_tzi;
692             NtClose(hkey);
693             return;
694         }
695
696         /* reset len */
697         nameW.Length = sizeof(buf);
698         nameW.MaximumLength = sizeof(buf);
699     }
700
701     NtClose(hkey);
702
703     FIXME("Can't find matching timezone information in the registry for "
704           "bias %d, std (d/m/y): %u/%02u/%04u, dlt (d/m/y): %u/%02u/%04u\n",
705           tzi->Bias,
706           tzi->StandardDate.wDay, tzi->StandardDate.wMonth, tzi->StandardDate.wYear,
707           tzi->DaylightDate.wDay, tzi->DaylightDate.wMonth, tzi->DaylightDate.wYear);
708 }
709
710 static time_t find_dst_change(unsigned long min, unsigned long max, int *is_dst)
711 {
712     time_t start;
713     struct tm *tm;
714
715     start = min;
716     tm = localtime(&start);
717     *is_dst = !tm->tm_isdst;
718     TRACE("starting date isdst %d, %s", !*is_dst, ctime(&start));
719
720     while (min <= max)
721     {
722         time_t pos = (min + max) / 2;
723         tm = localtime(&pos);
724
725         if (tm->tm_isdst != *is_dst)
726             min = pos + 1;
727         else
728             max = pos - 1;
729     }
730     return min;
731 }
732
733 static int init_tz_info(RTL_TIME_ZONE_INFORMATION *tzi)
734 {
735     static RTL_TIME_ZONE_INFORMATION cached_tzi;
736     static int current_year = -1, current_bias = 65535;
737     struct tm *tm;
738     time_t year_start, year_end, tmp, dlt = 0, std = 0;
739     int is_dst, current_is_dst, bias;
740
741     RtlEnterCriticalSection( &TIME_tz_section );
742
743     year_start = time(NULL);
744     tm = gmtime(&year_start);
745     bias = (LONG)(mktime(tm) - year_start) / 60;
746
747     tm = localtime(&year_start);
748     current_is_dst = tm->tm_isdst;
749     if (current_year == tm->tm_year && current_bias == bias)
750     {
751         *tzi = cached_tzi;
752         RtlLeaveCriticalSection( &TIME_tz_section );
753         return current_is_dst;
754     }
755
756     memset(tzi, 0, sizeof(*tzi));
757
758     TRACE("tz data will be valid through year %d, bias %d\n", tm->tm_year + 1900, bias);
759     current_year = tm->tm_year;
760     current_bias = bias;
761
762     tzi->Bias = bias;
763
764     tm->tm_isdst = 0;
765     tm->tm_mday = 1;
766     tm->tm_mon = tm->tm_hour = tm->tm_min = tm->tm_sec = tm->tm_wday = tm->tm_yday = 0;
767     year_start = mktime(tm);
768     TRACE("year_start: %s", ctime(&year_start));
769
770     tm->tm_mday = tm->tm_wday = tm->tm_yday = 0;
771     tm->tm_mon = 12;
772     tm->tm_hour = 23;
773     tm->tm_min = tm->tm_sec = 59;
774     year_end = mktime(tm);
775     TRACE("year_end: %s", ctime(&year_end));
776
777     tmp = find_dst_change(year_start, year_end, &is_dst);
778     if (is_dst)
779         dlt = tmp;
780     else
781         std = tmp;
782
783     tmp = find_dst_change(tmp, year_end, &is_dst);
784     if (is_dst)
785         dlt = tmp;
786     else
787         std = tmp;
788
789     TRACE("std: %s", ctime(&std));
790     TRACE("dlt: %s", ctime(&dlt));
791
792     if (dlt == std || !dlt || !std)
793         TRACE("there is no daylight saving rules in this time zone\n");
794     else
795     {
796         tmp = dlt - tzi->Bias * 60;
797         tm = gmtime(&tmp);
798         TRACE("dlt gmtime: %s", asctime(tm));
799
800         tzi->DaylightBias = -60;
801         tzi->DaylightDate.wYear = tm->tm_year + 1900;
802         tzi->DaylightDate.wMonth = tm->tm_mon + 1;
803         tzi->DaylightDate.wDayOfWeek = tm->tm_wday;
804         tzi->DaylightDate.wDay = tm->tm_mday;
805         tzi->DaylightDate.wHour = tm->tm_hour;
806         tzi->DaylightDate.wMinute = tm->tm_min;
807         tzi->DaylightDate.wSecond = tm->tm_sec;
808         tzi->DaylightDate.wMilliseconds = 0;
809
810         TRACE("daylight (d/m/y): %u/%02u/%04u day of week %u %u:%02u:%02u.%03u bias %d\n",
811             tzi->DaylightDate.wDay, tzi->DaylightDate.wMonth,
812             tzi->DaylightDate.wYear, tzi->DaylightDate.wDayOfWeek,
813             tzi->DaylightDate.wHour, tzi->DaylightDate.wMinute,
814             tzi->DaylightDate.wSecond, tzi->DaylightDate.wMilliseconds,
815             tzi->DaylightBias);
816
817         tmp = std - tzi->Bias * 60 - tzi->DaylightBias * 60;
818         tm = gmtime(&tmp);
819         TRACE("std gmtime: %s", asctime(tm));
820
821         tzi->StandardBias = 0;
822         tzi->StandardDate.wYear = tm->tm_year + 1900;
823         tzi->StandardDate.wMonth = tm->tm_mon + 1;
824         tzi->StandardDate.wDayOfWeek = tm->tm_wday;
825         tzi->StandardDate.wDay = tm->tm_mday;
826         tzi->StandardDate.wHour = tm->tm_hour;
827         tzi->StandardDate.wMinute = tm->tm_min;
828         tzi->StandardDate.wSecond = tm->tm_sec;
829         tzi->StandardDate.wMilliseconds = 0;
830
831         TRACE("standard (d/m/y): %u/%02u/%04u day of week %u %u:%02u:%02u.%03u bias %d\n",
832             tzi->StandardDate.wDay, tzi->StandardDate.wMonth,
833             tzi->StandardDate.wYear, tzi->StandardDate.wDayOfWeek,
834             tzi->StandardDate.wHour, tzi->StandardDate.wMinute,
835             tzi->StandardDate.wSecond, tzi->StandardDate.wMilliseconds,
836             tzi->StandardBias);
837     }
838
839     find_reg_tz_info(tzi);
840     cached_tzi = *tzi;
841
842     RtlLeaveCriticalSection( &TIME_tz_section );
843
844     return current_is_dst;
845 }
846
847 /***********************************************************************
848  *      RtlQueryTimeZoneInformation [NTDLL.@]
849  *
850  * Get information about the current timezone.
851  *
852  * PARAMS
853  *   tzinfo [O] Destination for the retrieved timezone info.
854  *
855  * RETURNS
856  *   Success: STATUS_SUCCESS.
857  *   Failure: An NTSTATUS error code indicating the problem.
858  */
859 NTSTATUS WINAPI RtlQueryTimeZoneInformation(RTL_TIME_ZONE_INFORMATION *tzinfo)
860 {
861     init_tz_info( tzinfo );
862
863     return STATUS_SUCCESS;
864 }
865
866 /***********************************************************************
867  *       RtlSetTimeZoneInformation [NTDLL.@]
868  *
869  * Set the current time zone information.
870  *
871  * PARAMS
872  *   tzinfo [I] Timezone information to set.
873  *
874  * RETURNS
875  *   Success: STATUS_SUCCESS.
876  *   Failure: An NTSTATUS error code indicating the problem.
877  *
878  */
879 NTSTATUS WINAPI RtlSetTimeZoneInformation( const RTL_TIME_ZONE_INFORMATION *tzinfo )
880 {
881     return STATUS_PRIVILEGE_NOT_HELD;
882 }
883
884 /***********************************************************************
885  *        NtSetSystemTime [NTDLL.@]
886  *        ZwSetSystemTime [NTDLL.@]
887  *
888  * Set the system time.
889  *
890  * PARAMS
891  *   NewTime [I] The time to set.
892  *   OldTime [O] Optional destination for the previous system time.
893  *
894  * RETURNS
895  *   Success: STATUS_SUCCESS.
896  *   Failure: An NTSTATUS error code indicating the problem.
897  */
898 NTSTATUS WINAPI NtSetSystemTime(const LARGE_INTEGER *NewTime, LARGE_INTEGER *OldTime)
899 {
900     struct timeval tv;
901     time_t tm_t;
902     DWORD sec, oldsec;
903     LARGE_INTEGER tm;
904
905     /* Return the old time if necessary */
906     if (!OldTime) OldTime = &tm;
907
908     NtQuerySystemTime( OldTime );
909     RtlTimeToSecondsSince1970( OldTime, &oldsec );
910
911     RtlTimeToSecondsSince1970( NewTime, &sec );
912
913     /* set the new time */
914     tv.tv_sec = sec;
915     tv.tv_usec = 0;
916
917 #ifdef HAVE_SETTIMEOFDAY
918     if (!settimeofday(&tv, NULL)) /* 0 is OK, -1 is error */
919         return STATUS_SUCCESS;
920     tm_t = sec;
921     ERR("Cannot set time to %s, time adjustment %ld: %s\n",
922         ctime(&tm_t), (long)(sec-oldsec), strerror(errno));
923     if (errno == EPERM)
924         return STATUS_PRIVILEGE_NOT_HELD;
925     else
926         return STATUS_INVALID_PARAMETER;
927 #else
928     tm_t = sec;
929     FIXME("setting time to %s not implemented for missing settimeofday\n",
930         ctime(&tm_t));
931     return STATUS_NOT_IMPLEMENTED;
932 #endif
933 }