1 // SPDX-License-Identifier: LGPL-2.0+
2 /* Copyright (C) 1993, 1994, 1995, 1996, 1997 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Paul Eggert (eggert@twinsun.com). */
5
6 /*
7 * dgb 10/02/98: ripped this from glibc source to help convert timestamps
8 * to unix time
9 * 10/04/98: added new table-based lookup after seeing how ugly
10 * the gnu code is
11 * blf 09/27/99: ripped out all the old code and inserted new table from
12 * John Brockmeyer (without leap second corrections)
13 * rewrote udf_stamp_to_time and fixed timezone accounting in
14 * udf_time_to_stamp.
15 */
16
17 /*
18 * We don't take into account leap seconds. This may be correct or incorrect.
19 * For more NIST information (especially dealing with leap seconds), see:
20 * http://www.boulder.nist.gov/timefreq/pubs/bulletin/leapsecond.htm
21 */
22
23 #include "udfdecl.h"
24
25 #include <linux/types.h>
26 #include <linux/kernel.h>
27 #include <linux/time.h>
28
29 void
udf_disk_stamp_to_time(struct timespec64 * dest,struct timestamp src)30 udf_disk_stamp_to_time(struct timespec64 *dest, struct timestamp src)
31 {
32 u16 typeAndTimezone = le16_to_cpu(src.typeAndTimezone);
33 u16 year = le16_to_cpu(src.year);
34 uint8_t type = typeAndTimezone >> 12;
35 int16_t offset;
36
37 if (type == 1) {
38 offset = typeAndTimezone << 4;
39 /* sign extent offset */
40 offset = (offset >> 4);
41 if (offset == -2047) /* unspecified offset */
42 offset = 0;
43 } else
44 offset = 0;
45
46 dest->tv_sec = mktime64(year, src.month, src.day, src.hour, src.minute,
47 src.second);
48 dest->tv_sec -= offset * 60;
49
50 /*
51 * Sanitize nanosecond field since reportedly some filesystems are
52 * recorded with bogus sub-second values.
53 */
54 if (src.centiseconds < 100 && src.hundredsOfMicroseconds < 100 &&
55 src.microseconds < 100) {
56 dest->tv_nsec = 1000 * (src.centiseconds * 10000 +
57 src.hundredsOfMicroseconds * 100 + src.microseconds);
58 } else {
59 dest->tv_nsec = 0;
60 }
61 }
62
63 void
udf_time_to_disk_stamp(struct timestamp * dest,struct timespec64 ts)64 udf_time_to_disk_stamp(struct timestamp *dest, struct timespec64 ts)
65 {
66 time64_t seconds;
67 int16_t offset;
68 struct tm tm;
69
70 offset = -sys_tz.tz_minuteswest;
71
72 dest->typeAndTimezone = cpu_to_le16(0x1000 | (offset & 0x0FFF));
73
74 seconds = ts.tv_sec + offset * 60;
75 time64_to_tm(seconds, 0, &tm);
76 dest->year = cpu_to_le16(tm.tm_year + 1900);
77 dest->month = tm.tm_mon + 1;
78 dest->day = tm.tm_mday;
79 dest->hour = tm.tm_hour;
80 dest->minute = tm.tm_min;
81 dest->second = tm.tm_sec;
82 dest->centiseconds = ts.tv_nsec / 10000000;
83 dest->hundredsOfMicroseconds = (ts.tv_nsec / 1000 -
84 dest->centiseconds * 10000) / 100;
85 dest->microseconds = (ts.tv_nsec / 1000 - dest->centiseconds * 10000 -
86 dest->hundredsOfMicroseconds * 100);
87 }
88
89 /* EOF */
90