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 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 dest->tv_nsec = 1000 * (src.centiseconds * 10000 + 50 src.hundredsOfMicroseconds * 100 + src.microseconds); 51 /* 52 * Sanitize nanosecond field since reportedly some filesystems are 53 * recorded with bogus sub-second values. 54 */ 55 dest->tv_nsec %= NSEC_PER_SEC; 56 } 57 58 void 59 udf_time_to_disk_stamp(struct timestamp *dest, struct timespec64 ts) 60 { 61 time64_t seconds; 62 int16_t offset; 63 struct tm tm; 64 65 offset = -sys_tz.tz_minuteswest; 66 67 dest->typeAndTimezone = cpu_to_le16(0x1000 | (offset & 0x0FFF)); 68 69 seconds = ts.tv_sec + offset * 60; 70 time64_to_tm(seconds, 0, &tm); 71 dest->year = cpu_to_le16(tm.tm_year + 1900); 72 dest->month = tm.tm_mon + 1; 73 dest->day = tm.tm_mday; 74 dest->hour = tm.tm_hour; 75 dest->minute = tm.tm_min; 76 dest->second = tm.tm_sec; 77 dest->centiseconds = ts.tv_nsec / 10000000; 78 dest->hundredsOfMicroseconds = (ts.tv_nsec / 1000 - 79 dest->centiseconds * 10000) / 100; 80 dest->microseconds = (ts.tv_nsec / 1000 - dest->centiseconds * 10000 - 81 dest->hundredsOfMicroseconds * 100); 82 } 83 84 /* EOF */ 85