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 to unix time 22 * 10/04/98: added new table-based lookup after seeing how ugly the gnu code is 23 * blf 09/27/99: ripped out all the old code and inserted new table from 24 * John Brockmeyer (without leap second corrections) 25 * rewrote udf_stamp_to_time and fixed timezone accounting in 26 udf_time_to_stamp. 27 */ 28 29 /* 30 * We don't take into account leap seconds. This may be correct or incorrect. 31 * For more NIST information (especially dealing with leap seconds), see: 32 * http://www.boulder.nist.gov/timefreq/pubs/bulletin/leapsecond.htm 33 */ 34 35 #include <linux/types.h> 36 #include <linux/kernel.h> 37 #include "udfdecl.h" 38 39 #define EPOCH_YEAR 1970 40 41 #ifndef __isleap 42 /* Nonzero if YEAR is a leap year (every 4 years, 43 except every 100th isn't, and every 400th is). */ 44 #define __isleap(year) \ 45 ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0)) 46 #endif 47 48 /* How many days come before each month (0-12). */ 49 const unsigned short int __mon_yday[2][13] = 50 { 51 /* Normal years. */ 52 { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 }, 53 /* Leap years. */ 54 { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 } 55 }; 56 57 #define MAX_YEAR_SECONDS 69 58 #define SPD 0x15180 /*3600*24*/ 59 #define SPY(y,l,s) (SPD * (365*y+l)+s) 60 61 static time_t year_seconds[MAX_YEAR_SECONDS]= { 62 /*1970*/ SPY( 0, 0,0), SPY( 1, 0,0), SPY( 2, 0,0), SPY( 3, 1,0), 63 /*1974*/ SPY( 4, 1,0), SPY( 5, 1,0), SPY( 6, 1,0), SPY( 7, 2,0), 64 /*1978*/ SPY( 8, 2,0), SPY( 9, 2,0), SPY(10, 2,0), SPY(11, 3,0), 65 /*1982*/ SPY(12, 3,0), SPY(13, 3,0), SPY(14, 3,0), SPY(15, 4,0), 66 /*1986*/ SPY(16, 4,0), SPY(17, 4,0), SPY(18, 4,0), SPY(19, 5,0), 67 /*1990*/ SPY(20, 5,0), SPY(21, 5,0), SPY(22, 5,0), SPY(23, 6,0), 68 /*1994*/ SPY(24, 6,0), SPY(25, 6,0), SPY(26, 6,0), SPY(27, 7,0), 69 /*1998*/ SPY(28, 7,0), SPY(29, 7,0), SPY(30, 7,0), SPY(31, 8,0), 70 /*2002*/ SPY(32, 8,0), SPY(33, 8,0), SPY(34, 8,0), SPY(35, 9,0), 71 /*2006*/ SPY(36, 9,0), SPY(37, 9,0), SPY(38, 9,0), SPY(39,10,0), 72 /*2010*/ SPY(40,10,0), SPY(41,10,0), SPY(42,10,0), SPY(43,11,0), 73 /*2014*/ SPY(44,11,0), SPY(45,11,0), SPY(46,11,0), SPY(47,12,0), 74 /*2018*/ SPY(48,12,0), SPY(49,12,0), SPY(50,12,0), SPY(51,13,0), 75 /*2022*/ SPY(52,13,0), SPY(53,13,0), SPY(54,13,0), SPY(55,14,0), 76 /*2026*/ SPY(56,14,0), SPY(57,14,0), SPY(58,14,0), SPY(59,15,0), 77 /*2030*/ SPY(60,15,0), SPY(61,15,0), SPY(62,15,0), SPY(63,16,0), 78 /*2034*/ SPY(64,16,0), SPY(65,16,0), SPY(66,16,0), SPY(67,17,0), 79 /*2038*/ SPY(68,17,0) 80 }; 81 82 extern struct timezone sys_tz; 83 84 #define SECS_PER_HOUR (60 * 60) 85 #define SECS_PER_DAY (SECS_PER_HOUR * 24) 86 87 time_t * 88 udf_stamp_to_time(time_t *dest, long *dest_usec, kernel_timestamp src) 89 { 90 int yday; 91 uint8_t type = src.typeAndTimezone >> 12; 92 int16_t offset; 93 94 if (type == 1) 95 { 96 offset = src.typeAndTimezone << 4; 97 /* sign extent offset */ 98 offset = (offset >> 4); 99 if (offset == -2047) /* unspecified offset */ 100 offset = 0; 101 } 102 else 103 offset = 0; 104 105 if ((src.year < EPOCH_YEAR) || 106 (src.year > EPOCH_YEAR+MAX_YEAR_SECONDS)) 107 { 108 *dest = -1; 109 *dest_usec = -1; 110 return NULL; 111 } 112 *dest = year_seconds[src.year - EPOCH_YEAR]; 113 *dest -= offset * 60; 114 115 yday = ((__mon_yday[__isleap (src.year)] 116 [src.month-1]) + (src.day-1)); 117 *dest += ( ( (yday* 24) + src.hour ) * 60 + src.minute ) * 60 + src.second; 118 *dest_usec = src.centiseconds * 10000 + src.hundredsOfMicroseconds * 100 + src.microseconds; 119 return dest; 120 } 121 122 123 kernel_timestamp * 124 udf_time_to_stamp(kernel_timestamp *dest, struct timespec ts) 125 { 126 long int days, rem, y; 127 const unsigned short int *ip; 128 int16_t offset; 129 130 offset = -sys_tz.tz_minuteswest; 131 132 if (!dest) 133 return NULL; 134 135 dest->typeAndTimezone = 0x1000 | (offset & 0x0FFF); 136 137 ts.tv_sec += offset * 60; 138 days = ts.tv_sec / SECS_PER_DAY; 139 rem = ts.tv_sec % SECS_PER_DAY; 140 dest->hour = rem / SECS_PER_HOUR; 141 rem %= SECS_PER_HOUR; 142 dest->minute = rem / 60; 143 dest->second = rem % 60; 144 y = 1970; 145 146 #define DIV(a,b) ((a) / (b) - ((a) % (b) < 0)) 147 #define LEAPS_THRU_END_OF(y) (DIV (y, 4) - DIV (y, 100) + DIV (y, 400)) 148 149 while (days < 0 || days >= (__isleap(y) ? 366 : 365)) 150 { 151 long int yg = y + days / 365 - (days % 365 < 0); 152 153 /* Adjust DAYS and Y to match the guessed year. */ 154 days -= ((yg - y) * 365 155 + LEAPS_THRU_END_OF (yg - 1) 156 - LEAPS_THRU_END_OF (y - 1)); 157 y = yg; 158 } 159 dest->year = y; 160 ip = __mon_yday[__isleap(y)]; 161 for (y = 11; days < (long int) ip[y]; --y) 162 continue; 163 days -= ip[y]; 164 dest->month = y + 1; 165 dest->day = days + 1; 166 167 dest->centiseconds = ts.tv_nsec / 10000000; 168 dest->hundredsOfMicroseconds = (ts.tv_nsec / 1000 - dest->centiseconds * 10000) / 100; 169 dest->microseconds = (ts.tv_nsec / 1000 - dest->centiseconds * 10000 - 170 dest->hundredsOfMicroseconds * 100); 171 return dest; 172 } 173 174 /* EOF */ 175