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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /fs/udf/udftime.c
Initial import
Diffstat (limited to 'fs/udf/udftime.c')
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diff --git a/fs/udf/udftime.c b/fs/udf/udftime.c
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+/* Copyright (C) 1993, 1994, 1995, 1996, 1997 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Paul Eggert (eggert@twinsun.com).
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+/*
+ * dgb 10/02/98: ripped this from glibc source to help convert timestamps
+ * to unix time
+ * 10/04/98: added new table-based lookup after seeing how ugly
+ * the gnu code is
+ * blf 09/27/99: ripped out all the old code and inserted new table from
+ * John Brockmeyer (without leap second corrections)
+ * rewrote udf_stamp_to_time and fixed timezone accounting in
+ * udf_time_to_stamp.
+ */
+
+/*
+ * We don't take into account leap seconds. This may be correct or incorrect.
+ * For more NIST information (especially dealing with leap seconds), see:
+ * http://www.boulder.nist.gov/timefreq/pubs/bulletin/leapsecond.htm
+ */
+
+#include "udfdecl.h"
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+
+#define EPOCH_YEAR 1970
+
+#ifndef __isleap
+/* Nonzero if YEAR is a leap year (every 4 years,
+ except every 100th isn't, and every 400th is). */
+#define __isleap(year) \
+ ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
+#endif
+
+/* How many days come before each month (0-12). */
+static const unsigned short int __mon_yday[2][13] = {
+ /* Normal years. */
+ {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365},
+ /* Leap years. */
+ {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366}
+};
+
+#define MAX_YEAR_SECONDS 69
+#define SPD 0x15180 /*3600*24 */
+#define SPY(y, l, s) (SPD * (365 * y + l) + s)
+
+static time_t year_seconds[MAX_YEAR_SECONDS] = {
+/*1970*/ SPY(0, 0, 0), SPY(1, 0, 0), SPY(2, 0, 0), SPY(3, 1, 0),
+/*1974*/ SPY(4, 1, 0), SPY(5, 1, 0), SPY(6, 1, 0), SPY(7, 2, 0),
+/*1978*/ SPY(8, 2, 0), SPY(9, 2, 0), SPY(10, 2, 0), SPY(11, 3, 0),
+/*1982*/ SPY(12, 3, 0), SPY(13, 3, 0), SPY(14, 3, 0), SPY(15, 4, 0),
+/*1986*/ SPY(16, 4, 0), SPY(17, 4, 0), SPY(18, 4, 0), SPY(19, 5, 0),
+/*1990*/ SPY(20, 5, 0), SPY(21, 5, 0), SPY(22, 5, 0), SPY(23, 6, 0),
+/*1994*/ SPY(24, 6, 0), SPY(25, 6, 0), SPY(26, 6, 0), SPY(27, 7, 0),
+/*1998*/ SPY(28, 7, 0), SPY(29, 7, 0), SPY(30, 7, 0), SPY(31, 8, 0),
+/*2002*/ SPY(32, 8, 0), SPY(33, 8, 0), SPY(34, 8, 0), SPY(35, 9, 0),
+/*2006*/ SPY(36, 9, 0), SPY(37, 9, 0), SPY(38, 9, 0), SPY(39, 10, 0),
+/*2010*/ SPY(40, 10, 0), SPY(41, 10, 0), SPY(42, 10, 0), SPY(43, 11, 0),
+/*2014*/ SPY(44, 11, 0), SPY(45, 11, 0), SPY(46, 11, 0), SPY(47, 12, 0),
+/*2018*/ SPY(48, 12, 0), SPY(49, 12, 0), SPY(50, 12, 0), SPY(51, 13, 0),
+/*2022*/ SPY(52, 13, 0), SPY(53, 13, 0), SPY(54, 13, 0), SPY(55, 14, 0),
+/*2026*/ SPY(56, 14, 0), SPY(57, 14, 0), SPY(58, 14, 0), SPY(59, 15, 0),
+/*2030*/ SPY(60, 15, 0), SPY(61, 15, 0), SPY(62, 15, 0), SPY(63, 16, 0),
+/*2034*/ SPY(64, 16, 0), SPY(65, 16, 0), SPY(66, 16, 0), SPY(67, 17, 0),
+/*2038*/ SPY(68, 17, 0)
+};
+
+#define SECS_PER_HOUR (60 * 60)
+#define SECS_PER_DAY (SECS_PER_HOUR * 24)
+
+struct timespec *
+udf_disk_stamp_to_time(struct timespec *dest, struct timestamp src)
+{
+ int yday;
+ u16 typeAndTimezone = le16_to_cpu(src.typeAndTimezone);
+ u16 year = le16_to_cpu(src.year);
+ uint8_t type = typeAndTimezone >> 12;
+ int16_t offset;
+
+ if (type == 1) {
+ offset = typeAndTimezone << 4;
+ /* sign extent offset */
+ offset = (offset >> 4);
+ if (offset == -2047) /* unspecified offset */
+ offset = 0;
+ } else
+ offset = 0;
+
+ if ((year < EPOCH_YEAR) ||
+ (year >= EPOCH_YEAR + MAX_YEAR_SECONDS)) {
+ return NULL;
+ }
+ dest->tv_sec = year_seconds[year - EPOCH_YEAR];
+ dest->tv_sec -= offset * 60;
+
+ yday = ((__mon_yday[__isleap(year)][src.month - 1]) + src.day - 1);
+ dest->tv_sec += (((yday * 24) + src.hour) * 60 + src.minute) * 60 + src.second;
+ dest->tv_nsec = 1000 * (src.centiseconds * 10000 +
+ src.hundredsOfMicroseconds * 100 + src.microseconds);
+ return dest;
+}
+
+struct timestamp *
+udf_time_to_disk_stamp(struct timestamp *dest, struct timespec ts)
+{
+ long int days, rem, y;
+ const unsigned short int *ip;
+ int16_t offset;
+
+ offset = -sys_tz.tz_minuteswest;
+
+ if (!dest)
+ return NULL;
+
+ dest->typeAndTimezone = cpu_to_le16(0x1000 | (offset & 0x0FFF));
+
+ ts.tv_sec += offset * 60;
+ days = ts.tv_sec / SECS_PER_DAY;
+ rem = ts.tv_sec % SECS_PER_DAY;
+ dest->hour = rem / SECS_PER_HOUR;
+ rem %= SECS_PER_HOUR;
+ dest->minute = rem / 60;
+ dest->second = rem % 60;
+ y = 1970;
+
+#define DIV(a, b) ((a) / (b) - ((a) % (b) < 0))
+#define LEAPS_THRU_END_OF(y) (DIV (y, 4) - DIV (y, 100) + DIV (y, 400))
+
+ while (days < 0 || days >= (__isleap(y) ? 366 : 365)) {
+ long int yg = y + days / 365 - (days % 365 < 0);
+
+ /* Adjust DAYS and Y to match the guessed year. */
+ days -= ((yg - y) * 365
+ + LEAPS_THRU_END_OF(yg - 1)
+ - LEAPS_THRU_END_OF(y - 1));
+ y = yg;
+ }
+ dest->year = cpu_to_le16(y);
+ ip = __mon_yday[__isleap(y)];
+ for (y = 11; days < (long int)ip[y]; --y)
+ continue;
+ days -= ip[y];
+ dest->month = y + 1;
+ dest->day = days + 1;
+
+ dest->centiseconds = ts.tv_nsec / 10000000;
+ dest->hundredsOfMicroseconds = (ts.tv_nsec / 1000 -
+ dest->centiseconds * 10000) / 100;
+ dest->microseconds = (ts.tv_nsec / 1000 - dest->centiseconds * 10000 -
+ dest->hundredsOfMicroseconds * 100);
+ return dest;
+}
+
+/* EOF */