1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
|
/*
* 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
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#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;
}
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;
}
|
