LXR linux/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
  43void
  44udf_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
  72void
  73udf_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 */
  99