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 <linux/types.h> 38 #include <linux/kernel.h> 39 #include "udfdecl.h" 40 41 #define EPOCH_YEAR 1970 42 43 #ifndef __isleap 44 /* Nonzero if YEAR is a leap year (every 4 years, 45 except every 100th isn't, and every 400th is). */ 46 #define __isleap(year) \ 47 ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0)) 48 #endif 49 50 /* How many days come before each month (0-12). */ 51 static const unsigned short int __mon_yday[2][13] = { 52 /* Normal years. */ 53 {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365}, 54 /* Leap years. */ 55 {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366} 56 }; 57 58 #define MAX_YEAR_SECONDS 69 59 #define SPD 0x15180 /*3600*24 */ 60 #define SPY(y, l, s) (SPD * (365 * y + l) + s) 61 62 static time_t year_seconds[MAX_YEAR_SECONDS] = { 63 /*1970*/ SPY(0, 0, 0), SPY(1, 0, 0), SPY(2, 0, 0), SPY(3, 1, 0), 64 /*1974*/ SPY(4, 1, 0), SPY(5, 1, 0), SPY(6, 1, 0), SPY(7, 2, 0), 65 /*1978*/ SPY(8, 2, 0), SPY(9, 2, 0), SPY(10, 2, 0), SPY(11, 3, 0), 66 /*1982*/ SPY(12, 3, 0), SPY(13, 3, 0), SPY(14, 3, 0), SPY(15, 4, 0), 67 /*1986*/ SPY(16, 4, 0), SPY(17, 4, 0), SPY(18, 4, 0), SPY(19, 5, 0), 68 /*1990*/ SPY(20, 5, 0), SPY(21, 5, 0), SPY(22, 5, 0), SPY(23, 6, 0), 69 /*1994*/ SPY(24, 6, 0), SPY(25, 6, 0), SPY(26, 6, 0), SPY(27, 7, 0), 70 /*1998*/ SPY(28, 7, 0), SPY(29, 7, 0), SPY(30, 7, 0), SPY(31, 8, 0), 71 /*2002*/ SPY(32, 8, 0), SPY(33, 8, 0), SPY(34, 8, 0), SPY(35, 9, 0), 72 /*2006*/ SPY(36, 9, 0), SPY(37, 9, 0), SPY(38, 9, 0), SPY(39, 10, 0), 73 /*2010*/ SPY(40, 10, 0), SPY(41, 10, 0), SPY(42, 10, 0), SPY(43, 11, 0), 74 /*2014*/ SPY(44, 11, 0), SPY(45, 11, 0), SPY(46, 11, 0), SPY(47, 12, 0), 75 /*2018*/ SPY(48, 12, 0), SPY(49, 12, 0), SPY(50, 12, 0), SPY(51, 13, 0), 76 /*2022*/ SPY(52, 13, 0), SPY(53, 13, 0), SPY(54, 13, 0), SPY(55, 14, 0), 77 /*2026*/ SPY(56, 14, 0), SPY(57, 14, 0), SPY(58, 14, 0), SPY(59, 15, 0), 78 /*2030*/ SPY(60, 15, 0), SPY(61, 15, 0), SPY(62, 15, 0), SPY(63, 16, 0), 79 /*2034*/ SPY(64, 16, 0), SPY(65, 16, 0), SPY(66, 16, 0), SPY(67, 17, 0), 80 /*2038*/ SPY(68, 17, 0) 81 }; 82 83 extern struct timezone sys_tz; 84 85 #define SECS_PER_HOUR (60 * 60) 86 #define SECS_PER_DAY (SECS_PER_HOUR * 24) 87 88 struct timespec *udf_disk_stamp_to_time(struct timespec *dest, timestamp src) 89 { 90 int yday; 91 u16 typeAndTimezone = le16_to_cpu(src.typeAndTimezone); 92 u16 year = le16_to_cpu(src.year); 93 uint8_t type = typeAndTimezone >> 12; 94 int16_t offset; 95 96 if (type == 1) { 97 offset = typeAndTimezone << 4; 98 /* sign extent offset */ 99 offset = (offset >> 4); 100 if (offset == -2047) /* unspecified offset */ 101 offset = 0; 102 } else 103 offset = 0; 104 105 if ((year < EPOCH_YEAR) || 106 (year >= EPOCH_YEAR + MAX_YEAR_SECONDS)) { 107 return NULL; 108 } 109 dest->tv_sec = year_seconds[year - EPOCH_YEAR]; 110 dest->tv_sec -= offset * 60; 111 112 yday = ((__mon_yday[__isleap(year)][src.month - 1]) + src.day - 1); 113 dest->tv_sec += (((yday * 24) + src.hour) * 60 + src.minute) * 60 + src.second; 114 dest->tv_nsec = 1000 * (src.centiseconds * 10000 + 115 src.hundredsOfMicroseconds * 100 + src.microseconds); 116 return dest; 117 } 118 119 timestamp *udf_time_to_disk_stamp(timestamp *dest, struct timespec ts) 120 { 121 long int days, rem, y; 122 const unsigned short int *ip; 123 int16_t offset; 124 125 offset = -sys_tz.tz_minuteswest; 126 127 if (!dest) 128 return NULL; 129 130 dest->typeAndTimezone = cpu_to_le16(0x1000 | (offset & 0x0FFF)); 131 132 ts.tv_sec += offset * 60; 133 days = ts.tv_sec / SECS_PER_DAY; 134 rem = ts.tv_sec % SECS_PER_DAY; 135 dest->hour = rem / SECS_PER_HOUR; 136 rem %= SECS_PER_HOUR; 137 dest->minute = rem / 60; 138 dest->second = rem % 60; 139 y = 1970; 140 141 #define DIV(a, b) ((a) / (b) - ((a) % (b) < 0)) 142 #define LEAPS_THRU_END_OF(y) (DIV (y, 4) - DIV (y, 100) + DIV (y, 400)) 143 144 while (days < 0 || days >= (__isleap(y) ? 366 : 365)) { 145 long int yg = y + days / 365 - (days % 365 < 0); 146 147 /* Adjust DAYS and Y to match the guessed year. */ 148 days -= ((yg - y) * 365 149 + LEAPS_THRU_END_OF(yg - 1) 150 - LEAPS_THRU_END_OF(y - 1)); 151 y = yg; 152 } 153 dest->year = cpu_to_le16(y); 154 ip = __mon_yday[__isleap(y)]; 155 for (y = 11; days < (long int)ip[y]; --y) 156 continue; 157 days -= ip[y]; 158 dest->month = y + 1; 159 dest->day = days + 1; 160 161 dest->centiseconds = ts.tv_nsec / 10000000; 162 dest->hundredsOfMicroseconds = (ts.tv_nsec / 1000 - 163 dest->centiseconds * 10000) / 100; 164 dest->microseconds = (ts.tv_nsec / 1000 - dest->centiseconds * 10000 - 165 dest->hundredsOfMicroseconds * 100); 166 return dest; 167 } 168 169 /* EOF */ 170