fs/udf/udftime.c

   1 /* Copyright (C) 1993, 1994, 1995, 1996, 1997 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Paul Eggert (eggert@twinsun.com).
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 /*
  21  * dgb 10/02/98: ripped this from glibc source to help convert timestamps
  22  *               to unix time
  23  *     10/04/98: added new table-based lookup after seeing how ugly
  24  *               the gnu code is
  25  * blf 09/27/99: ripped out all the old code and inserted new table from
  26  *               John Brockmeyer (without leap second corrections)
  27  *               rewrote udf_stamp_to_time and fixed timezone accounting in
  28  *               udf_time_to_stamp.
  29  */
  30
  31 /*
  32  * We don't take into account leap seconds. This may be correct or incorrect.
  33  * For more NIST information (especially dealing with leap seconds), see:
  34  * http://www.boulder.nist.gov/timefreq/pubs/bulletin/leapsecond.htm
  35  */
  36
  37 #include "udfdecl.h"
  38
  39 #include <linux/types.h>
  40 #include <linux/kernel.h>
  41 #include <linux/time.h>
  42
  43 void
  44 udf_disk_stamp_to_time(struct timespec64 *dest, struct timestamp src)
  45 {
  46         u16 typeAndTimezone = le16_to_cpu(src.typeAndTimezone);
  47         u16 year = le16_to_cpu(src.year);
  48         uint8_t type = typeAndTimezone >> 12;
  49         int16_t offset;
  50
  51         if (type == 1) {
  52                 offset = typeAndTimezone << 4;
  53                 /* sign extent offset */
  54                 offset = (offset >> 4);
  55                 if (offset == -2047) /* unspecified offset */
  56                         offset = 0;
  57         } else
  58                 offset = 0;
  59
  60         dest->tv_sec = mktime64(year, src.month, src.day, src.hour, src.minute,
  61                         src.second);
  62         dest->tv_sec -= offset * 60;
  63         dest->tv_nsec = 1000 * (src.centiseconds * 10000 +
  64                         src.hundredsOfMicroseconds * 100 + src.microseconds);
  65         /*
  66          * Sanitize nanosecond field since reportedly some filesystems are
  67          * recorded with bogus sub-second values.
  68          */
  69         dest->tv_nsec %= NSEC_PER_SEC;
  70 }
  71
  72 void
  73 udf_time_to_disk_stamp(struct timestamp *dest, struct timespec64 ts)
  74 {
  75         time64_t seconds;
  76         int16_t offset;
  77         struct tm tm;
  78
  79         offset = -sys_tz.tz_minuteswest;
  80
  81         dest->typeAndTimezone = cpu_to_le16(0x1000 | (offset & 0x0FFF));
  82
  83         seconds = ts.tv_sec + offset * 60;
  84         time64_to_tm(seconds, 0, &tm);
  85         dest->year = cpu_to_le16(tm.tm_year + 1900);
  86         dest->month = tm.tm_mon + 1;
  87         dest->day = tm.tm_mday;
  88         dest->hour = tm.tm_hour;
  89         dest->minute = tm.tm_min;
  90         dest->second = tm.tm_sec;
  91         dest->centiseconds = ts.tv_nsec / 10000000;
  92         dest->hundredsOfMicroseconds = (ts.tv_nsec / 1000 -
  93                                         dest->centiseconds * 10000) / 100;
  94         dest->microseconds = (ts.tv_nsec / 1000 - dest->centiseconds * 10000 -
  95                               dest->hundredsOfMicroseconds * 100);
  96 }
  97
  98 /* EOF */