/*
* Adaptation of NetBSD code for RTEMS by Victor V. Vengerov <vvv@oktet.ru>
*/
/* $NetBSD: msdosfs_conv.c,v 1.10 1994/12/27 18:36:24 mycroft Exp $ */
/*
* Written by Paul Popelka (paulp@uts.amdahl.com)
*
* You can do anything you want with this software, just don't say you wrote
* it, and don't remove this notice.
*
* This software is provided "as is".
*
* The author supplies this software to be publicly redistributed on the
* understanding that the author is not responsible for the correct
* functioning of this software in any circumstances and is not liable for
* any damages caused by this software.
*
* October 1992
*/
#include <rtems.h>
#include "msdos.h"
/*
* Days in each month in a regular year.
*/
static u_short regyear[] = {
31, 28, 31, 30, 31, 30,
31, 31, 30, 31, 30, 31
};
/*
* Days in each month in a leap year.
*/
static u_short leapyear[] = {
31, 29, 31, 30, 31, 30,
31, 31, 30, 31, 30, 31
};
/*
* Variables used to remember parts of the last time conversion. Maybe we
* can avoid a full conversion.
*/
static u_long lasttime;
static u_long lastday;
static u_short lastddate;
static u_short lastdtime;
/*
* Convert the unix version of time to dos's idea of time to be used in
* file timestamps. The passed in unix time is assumed to be in GMT.
*/
void
msdos_date_unix2dos(unsigned int t, unsigned short *ddp,
unsigned short *dtp)
{
u_long days;
u_long inc;
u_long year;
u_long month;
u_short *months;
/*
* If the time from the last conversion is the same as now, then
* skip the computations and use the saved result.
*/
if (lasttime != t) {
lasttime = t;
lastdtime = (((t % 60) >> 1) << MSDOS_DT_2SECONDS_SHIFT)
+ (((t / 60) % 60) << MSDOS_DT_MINUTES_SHIFT)
+ (((t / 3600) % 24) << MSDOS_DT_HOURS_SHIFT);
/*
* If the number of days since 1970 is the same as the last
* time we did the computation then skip all this leap year
* and month stuff.
*/
days = t / (24 * 60 * 60);
if (days != lastday) {
lastday = days;
for (year = 1970;; year++) {
inc = year & 0x03 ? 365 : 366;
if (days < inc)
break;
days -= inc;
}
months = year & 0x03 ? regyear : leapyear;
for (month = 0; month < 12; month++) {
if (days < months[month])
break;
days -= months[month];
}
lastddate = ((days + 1) << MSDOS_DD_DAY_SHIFT)
+ ((month + 1) << MSDOS_DD_MONTH_SHIFT);
/*
* Remember dos's idea of time is relative to 1980.
* unix's is relative to 1970. If somehow we get a
* time before 1980 then don't give totally crazy
* results.
*/
if (year > 1980)
lastddate += (year - 1980) <<
MSDOS_DD_YEAR_SHIFT;
}
}
*dtp = lastdtime;
*ddp = lastddate;
}
/*
* The number of seconds between Jan 1, 1970 and Jan 1, 1980. In that
* interval there were 8 regular years and 2 leap years.
*/
#define SECONDSTO1980 (((8 * 365) + (2 * 366)) * (24 * 60 * 60))
static u_short lastdosdate;
static u_long lastseconds;
/*
* Convert from dos' idea of time to unix'. This will probably only be
* called from the stat(), and fstat() system calls and so probably need
* not be too efficient.
*/
unsigned int
msdos_date_dos2unix(unsigned int dd, unsigned int dt)
{
u_long seconds;
u_long m, month;
u_long y, year;
u_long days;
u_short *months;
seconds = ((dt & MSDOS_DT_2SECONDS_MASK) >> MSDOS_DT_2SECONDS_SHIFT)
+ ((dt & MSDOS_DT_MINUTES_MASK) >> MSDOS_DT_MINUTES_SHIFT) * 60
+ ((dt & MSDOS_DT_HOURS_MASK) >> MSDOS_DT_HOURS_SHIFT) * 3600;
/*
* If the year, month, and day from the last conversion are the
* same then use the saved value.
*/
if (lastdosdate != dd) {
lastdosdate = dd;
days = 0;
year = (dd & MSDOS_DD_YEAR_MASK) >> MSDOS_DD_YEAR_SHIFT;
for (y = 0; y < year; y++)
days += y & 0x03 ? 365 : 366;
months = year & 0x03 ? regyear : leapyear;
/*
* Prevent going from 0 to 0xffffffff in the following
* loop.
*/
month = (dd & MSDOS_DD_MONTH_MASK) >> MSDOS_DD_MONTH_SHIFT;
if (month == 0) {
month = 1;
}
for (m = 0; m < month - 1; m++)
days += months[m];
days += ((dd & MSDOS_DD_DAY_MASK) >> MSDOS_DD_DAY_SHIFT) - 1;
lastseconds = (days * 24 * 60 * 60) + SECONDSTO1980;
}
return seconds + lastseconds;
}
/*
* Cheezy macros to do case detection and conversion for the ascii
* character set. DOESN'T work for ebcdic.
*/
#define isupper(c) (c >= 'A' && c <= 'Z')
#define islower(c) (c >= 'a' && c <= 'z')
#define toupper(c) (c & ~' ')
#define tolower(c) (c | ' ')
static const u_char msdos_map[] = {
/* 00 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* 08 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* 10 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* 18 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* 20 */ 0x00, 0x21, 0x00, 0x23, 0x24, 0x25, 0x26, 0x27, /* !"#$%&' */
/* 28 */ 0x28, 0x29, 0x00, 0x00, 0x00, 0x2D, 0x2E, 0x00, /* ()*+,-./ */
/* 30 */ 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, /* 01234567 */
/* 38 */ 0x38, 0x39, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 89:;<=>? */
/* 40 */ 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, /* @ABCDEFG */
/* 48 */ 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, /* HIJKLMNO */
/* 50 */ 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, /* PQRSTUVW */
/* 58 */ 0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x00, 0x5E, 0x5F, /* XYZ[\]^_ */
/* 60 */ 0x60, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, /* `abcdefg */
/* 68 */ 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, /* hijklmno */
/* 70 */ 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, /* pqrstuvw */
/* 78 */ 0x58, 0x59, 0x5A, 0x5B, 0x7C, 0x00, 0x7E, 0x00, /* xyz{|}~ */
/* 80 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* 88 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* 90 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* 98 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* A0 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* A8 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* B0 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* B8 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* C0 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* C8 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* D0 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* D8 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* E0 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* E8 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* F0 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
/* F8 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
};
/*
* Convert a unix filename to a DOS filename. Return -1 if wrong name is
* supplied.
*/
int
msdos_filename_unix2dos(char *un, int unlen, char *dn)
{
int i;
u_char c;
/*
* Fill the dos filename string with blanks. These are DOS's pad
* characters.
*/
for (i = 0; i <= 10; i++)
dn[i] = ' ';
/*
* The filenames "." and ".." are handled specially, since they
* don't follow dos filename rules.
*/
if (un[0] == '.' && unlen == 1) {
dn[0] = '.';
return 0;
}
if (un[0] == '.' && un[1] == '.' && unlen == 2) {
dn[0] = '.';
dn[1] = '.';
return 0;
}
/*
* Copy the unix filename into the dos filename string upto the end
* of string, a '.', or 8 characters. Whichever happens first stops
* us. This forms the name portion of the dos filename. Fold to
* upper case.
*/
for (i = 0; i <= 7 && unlen && (c = *un) && c != '.'; i++) {
if ((dn[i] = msdos_map[c]) == 0)
return -1;
un++;
unlen--;
}
/*
* Strip any further characters up to a '.' or the end of the
* string.
*/
while (unlen && (c = *un)) {
un++;
unlen--;
/* Make sure we've skipped over the dot before stopping. */
if (c == '.')
break;
}
/*
* Copy in the extension part of the name, if any. Force to upper
* case. Note that the extension is allowed to contain '.'s.
* Filenames in this form are probably inaccessable under dos.
*/
for (i = 8; i <= 10 && unlen && (c = *un); i++) {
if ((dn[i] = msdos_map[c]) == 0)
return -1;
un++;
unlen--;
}
return 0;
}
