1 /* $OpenBSD: msdosfs_conv.c,v 1.3 2023/08/11 04:51:36 guenther Exp $ */
2 /* $NetBSD: msdosfs_conv.c,v 1.24 1997/10/17 11:23:54 ws Exp $ */
3
4 /*-
5 * Copyright (C) 1995, 1997 Wolfgang Solfrank.
6 * Copyright (C) 1995, 1997 TooLs GmbH.
7 * All rights reserved.
8 * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by TooLs GmbH.
21 * 4. The name of TooLs GmbH may not be used to endorse or promote products
22 * derived from this software without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
29 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
30 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
31 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
32 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
33 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35 /*
36 * Written by Paul Popelka (paulp@uts.amdahl.com)
37 *
38 * You can do anything you want with this software, just don't say you wrote
39 * it, and don't remove this notice.
40 *
41 * This software is provided "as is".
42 *
43 * The author supplies this software to be publicly redistributed on the
44 * understanding that the author is not responsible for the correct
45 * functioning of this software in any circumstances and is not liable for
46 * any damages caused by this software.
47 *
48 * October 1992
49 */
50
51 /*
52 * System include files.
53 */
54 #include <sys/time.h>
55 #include <sys/dirent.h>
56 #include <sys/lock.h>
57
58 /*
59 * MSDOSFS include files.
60 */
61 #include "msdos/direntry.h"
62 #include "msdos/denode.h"
63
64 /*
65 * Days in each month in a regular year.
66 */
67 const u_short regyear[] = {
68 31, 28, 31, 30, 31, 30,
69 31, 31, 30, 31, 30, 31
70 };
71
72 /*
73 * Days in each month in a leap year.
74 */
75 const u_short leapyear[] = {
76 31, 29, 31, 30, 31, 30,
77 31, 31, 30, 31, 30, 31
78 };
79
80 /*
81 * Variables used to remember parts of the last time conversion. Maybe we
82 * can avoid a full conversion.
83 */
84 time_t lasttime;
85 uint32_t lastday;
86 u_short lastddate;
87 u_short lastdtime;
88
89 /*
90 * Convert the unix version of time to dos's idea of time to be used in
91 * file timestamps. The passed in unix time is assumed to be in GMT.
92 */
93 void
unix2dostime(const struct timespec * tsp,int minuteswest,u_int16_t * ddp,u_int16_t * dtp,u_int8_t * dhp)94 unix2dostime(const struct timespec *tsp, int minuteswest, u_int16_t *ddp,
95 u_int16_t *dtp, u_int8_t *dhp)
96 {
97 time_t t;
98 uint32_t days;
99 uint32_t inc;
100 uint32_t year;
101 uint32_t month;
102 const u_short *months;
103
104 /*
105 * If the time from the last conversion is the same as now, then
106 * skip the computations and use the saved result.
107 */
108 t = tsp->tv_sec - (minuteswest * 60)
109 /* +- daylight saving time correction */ ;
110 t &= ~1;
111 /*
112 * Before 1/1/1980 there is only a timeless void. After 12/31/2107
113 * there is only Cthulhu.
114 */
115 #define DOSEPOCH 315532800LL
116 #define DOSENDTIME 4354775999LL
117 if (t < DOSEPOCH || t > DOSENDTIME)
118 t = DOSEPOCH;
119
120 if (lasttime != t) {
121 lasttime = t;
122 lastdtime = (((t / 2) % 30) << DT_2SECONDS_SHIFT)
123 + (((t / 60) % 60) << DT_MINUTES_SHIFT)
124 + (((t / 3600) % 24) << DT_HOURS_SHIFT);
125
126 /*
127 * If the number of days since 1970 is the same as the last
128 * time we did the computation then skip all this leap year
129 * and month stuff.
130 */
131 days = t / (24 * 60 * 60);
132 if (days != lastday) {
133 lastday = days;
134 for (year = 1970;; year++) {
135 inc = year & 0x03 ? 365 : 366;
136 if (days < inc)
137 break;
138 days -= inc;
139 }
140 months = year & 0x03 ? regyear : leapyear;
141 for (month = 0; month < 12; month++) {
142 if (days < months[month])
143 break;
144 days -= months[month];
145 }
146 lastddate = ((days + 1) << DD_DAY_SHIFT)
147 + ((month + 1) << DD_MONTH_SHIFT);
148 /*
149 * Remember dos's idea of time is relative to 1980.
150 * unix's is relative to 1970. If somehow we get a
151 * time before 1980 then don't give totally crazy
152 * results.
153 */
154 if (year > 1980)
155 lastddate += (year - 1980) << DD_YEAR_SHIFT;
156 }
157 }
158
159 if (dtp != NULL)
160 *dtp = lastdtime;
161 if (dhp != NULL)
162 *dhp = (tsp->tv_sec & 1) * 100 + tsp->tv_nsec / 10000000;
163
164 *ddp = lastddate;
165 }
166
167 static const u_char
168 unix2dos[256] = {
169 0, 0, 0, 0, 0, 0, 0, 0, /* 00-07 */
170 0, 0, 0, 0, 0, 0, 0, 0, /* 08-0f */
171 0, 0, 0, 0, 0, 0, 0, 0, /* 10-17 */
172 0, 0, 0, 0, 0, 0, 0, 0, /* 18-1f */
173 0, 0x21, 0, 0x23, 0x24, 0x25, 0x26, 0x27, /* 20-27 */
174 0x28, 0x29, 0, 0, 0, 0x2d, 0, 0, /* 28-2f */
175 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, /* 30-37 */
176 0x38, 0x39, 0, 0, 0, 0, 0, 0, /* 38-3f */
177 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, /* 40-47 */
178 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, /* 48-4f */
179 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, /* 50-57 */
180 0x58, 0x59, 0x5a, 0, 0, 0, 0x5e, 0x5f, /* 58-5f */
181 0x60, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, /* 60-67 */
182 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, /* 68-6f */
183 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, /* 70-77 */
184 0x58, 0x59, 0x5a, 0x7b, 0, 0x7d, 0x7e, 0, /* 78-7f */
185 0, 0, 0, 0, 0, 0, 0, 0, /* 80-87 */
186 0, 0, 0, 0, 0, 0, 0, 0, /* 88-8f */
187 0, 0, 0, 0, 0, 0, 0, 0, /* 90-97 */
188 0, 0, 0, 0, 0, 0, 0, 0, /* 98-9f */
189 0, 0xad, 0xbd, 0x9c, 0xcf, 0xbe, 0xdd, 0xf5, /* a0-a7 */
190 0xf9, 0xb8, 0xa6, 0xae, 0xaa, 0xf0, 0xa9, 0xee, /* a8-af */
191 0xf8, 0xf1, 0xfd, 0xfc, 0xef, 0xe6, 0xf4, 0xfa, /* b0-b7 */
192 0xf7, 0xfb, 0xa7, 0xaf, 0xac, 0xab, 0xf3, 0xa8, /* b8-bf */
193 0xb7, 0xb5, 0xb6, 0xc7, 0x8e, 0x8f, 0x92, 0x80, /* c0-c7 */
194 0xd4, 0x90, 0xd2, 0xd3, 0xde, 0xd6, 0xd7, 0xd8, /* c8-cf */
195 0xd1, 0xa5, 0xe3, 0xe0, 0xe2, 0xe5, 0x99, 0x9e, /* d0-d7 */
196 0x9d, 0xeb, 0xe9, 0xea, 0x9a, 0xed, 0xe8, 0xe1, /* d8-df */
197 0xb7, 0xb5, 0xb6, 0xc7, 0x8e, 0x8f, 0x92, 0x80, /* e0-e7 */
198 0xd4, 0x90, 0xd2, 0xd3, 0xde, 0xd6, 0xd7, 0xd8, /* e8-ef */
199 0xd1, 0xa5, 0xe3, 0xe0, 0xe2, 0xe5, 0x99, 0xf6, /* f0-f7 */
200 0x9d, 0xeb, 0xe9, 0xea, 0x9a, 0xed, 0xe8, 0x98, /* f8-ff */
201 };
202
203 static const u_char
204 u2l[256] = {
205 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* 00-07 */
206 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, /* 08-0f */
207 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, /* 10-17 */
208 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, /* 18-1f */
209 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, /* 20-27 */
210 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, /* 28-2f */
211 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, /* 30-37 */
212 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, /* 38-3f */
213 0x40, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, /* 40-47 */
214 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, /* 48-4f */
215 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, /* 50-57 */
216 0x78, 0x79, 0x7a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, /* 58-5f */
217 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, /* 60-67 */
218 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, /* 68-6f */
219 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, /* 70-77 */
220 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, /* 78-7f */
221 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, /* 80-87 */
222 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, /* 88-8f */
223 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, /* 90-97 */
224 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, /* 98-9f */
225 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, /* a0-a7 */
226 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, /* a8-af */
227 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, /* b0-b7 */
228 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, /* b8-bf */
229 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, /* c0-c7 */
230 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, /* c8-cf */
231 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xd7, /* d0-d7 */
232 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xdf, /* d8-df */
233 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, /* e0-e7 */
234 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, /* e8-ef */
235 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, /* f0-f7 */
236 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, /* f8-ff */
237 };
238
239 /*
240 * DOS filenames are made of 2 parts, the name part and the extension part.
241 * The name part is 8 characters long and the extension part is 3
242 * characters long. They may contain trailing blanks if the name or
243 * extension are not long enough to fill their respective fields.
244 */
245
246 /*
247 * Convert a unix filename to a DOS filename according to Win95 rules.
248 * If applicable and gen is not 0, it is inserted into the converted
249 * filename as a generation number.
250 * Returns
251 * 0 if name couldn't be converted
252 * 1 if the converted name is the same as the original
253 * (no long filename entry necessary for Win95)
254 * 2 if conversion was successful
255 * 3 if conversion was successful and generation number was inserted
256 */
257 int
unix2dosfn(u_char * un,u_char dn[11],int unlen,u_int gen)258 unix2dosfn(u_char *un, u_char dn[11], int unlen, u_int gen)
259 {
260 int i, j, l;
261 int conv = 1;
262 u_char *cp, *dp, *dp1;
263 u_char gentext[6];
264
265 /*
266 * Fill the dos filename string with blanks. These are DOS's pad
267 * characters.
268 */
269 for (i = 0; i < 11; i++)
270 dn[i] = ' ';
271
272 /*
273 * The filenames "." and ".." are handled specially, since they
274 * don't follow dos filename rules.
275 */
276 if (un[0] == '.' && unlen == 1) {
277 dn[0] = '.';
278 return gen <= 1;
279 }
280 if (un[0] == '.' && un[1] == '.' && unlen == 2) {
281 dn[0] = '.';
282 dn[1] = '.';
283 return gen <= 1;
284 }
285
286 /*
287 * Filenames with only blanks and dots are not allowed!
288 */
289 for (cp = un, i = unlen; --i >= 0; cp++)
290 if (*cp != ' ' && *cp != '.')
291 break;
292 if (i < 0)
293 return 0;
294
295 /*
296 * Now find the extension
297 * Note: dot as first char doesn't start extension
298 * and trailing dots and blanks are ignored
299 */
300 dp = dp1 = 0;
301 for (cp = un + 1, i = unlen - 1; --i >= 0;) {
302 switch (*cp++) {
303 case '.':
304 if (!dp1)
305 dp1 = cp;
306 break;
307 case ' ':
308 break;
309 default:
310 if (dp1)
311 dp = dp1;
312 dp1 = 0;
313 break;
314 }
315 }
316
317 /*
318 * Now convert it
319 */
320 if (dp) {
321 if (dp1)
322 l = dp1 - dp;
323 else
324 l = unlen - (dp - un);
325 for (i = 0, j = 8; i < l && j < 11; i++, j++) {
326 if (dp[i] != (dn[j] = unix2dos[dp[i]])
327 && conv != 3)
328 conv = 2;
329 if (!dn[j]) {
330 conv = 3;
331 dn[j--] = ' ';
332 }
333 }
334 if (i < l)
335 conv = 3;
336 dp--;
337 } else {
338 for (dp = cp; *--dp == ' ' || *dp == '.';);
339 dp++;
340 }
341
342 /*
343 * Now convert the rest of the name
344 */
345 for (i = j = 0; un < dp && j < 8; i++, j++, un++) {
346 if (*un != (dn[j] = unix2dos[*un])
347 && conv != 3)
348 conv = 2;
349 if (!dn[j]) {
350 conv = 3;
351 dn[j--] = ' ';
352 }
353 }
354 if (un < dp)
355 conv = 3;
356 /*
357 * If we didn't have any chars in filename,
358 * generate a default
359 */
360 if (!j)
361 dn[0] = '_';
362
363 /*
364 * The first character cannot be E5,
365 * because that means a deleted entry
366 */
367 if (dn[0] == 0xe5)
368 dn[0] = SLOT_E5;
369
370 /*
371 * If there wasn't any char dropped,
372 * there is no place for generation numbers
373 */
374 if (conv != 3) {
375 if (gen > 1)
376 return 0;
377 return conv;
378 }
379
380 /*
381 * Now insert the generation number into the filename part
382 */
383 for (cp = gentext + sizeof(gentext); cp > gentext && gen; gen /= 10)
384 *--cp = gen % 10 + '0';
385 if (gen)
386 return 0;
387 for (i = 8; dn[--i] == ' ';);
388 if (gentext + sizeof(gentext) - cp + 1 > 8 - i)
389 i = 8 - (gentext + sizeof(gentext) - cp + 1);
390 dn[i++] = '~';
391 while (cp < gentext + sizeof(gentext))
392 dn[i++] = *cp++;
393 return 3;
394 }
395
396 /*
397 * Create a Win95 long name directory entry
398 * Note: assumes that the filename is valid,
399 * i.e. doesn't consist solely of blanks and dots
400 */
401 int
unix2winfn(u_char * un,int unlen,struct winentry * wep,int cnt,int chksum)402 unix2winfn(u_char *un, int unlen, struct winentry *wep, int cnt, int chksum)
403 {
404 u_int8_t *cp;
405 int i;
406
407 /*
408 * Drop trailing blanks and dots
409 */
410 for (cp = un + unlen; *--cp == ' ' || *cp == '.'; unlen--);
411
412 un += (cnt - 1) * WIN_CHARS;
413 unlen -= (cnt - 1) * WIN_CHARS;
414
415 /*
416 * Initialize winentry to some useful default
417 */
418 for (cp = (u_int8_t *)wep, i = sizeof(*wep); --i >= 0; *cp++ = 0xff);
419 wep->weCnt = cnt;
420 wep->weAttributes = ATTR_WIN95;
421 wep->weReserved1 = 0;
422 wep->weChksum = chksum;
423 wep->weReserved2 = 0;
424
425 /*
426 * Now convert the filename parts
427 */
428 for (cp = wep->wePart1, i = sizeof(wep->wePart1)/2; --i >= 0;) {
429 if (--unlen < 0)
430 goto done;
431 *cp++ = *un++;
432 *cp++ = 0;
433 }
434 for (cp = wep->wePart2, i = sizeof(wep->wePart2)/2; --i >= 0;) {
435 if (--unlen < 0)
436 goto done;
437 *cp++ = *un++;
438 *cp++ = 0;
439 }
440 for (cp = wep->wePart3, i = sizeof(wep->wePart3)/2; --i >= 0;) {
441 if (--unlen < 0)
442 goto done;
443 *cp++ = *un++;
444 *cp++ = 0;
445 }
446 if (!unlen)
447 wep->weCnt |= WIN_LAST;
448 return unlen;
449
450 done:
451 *cp++ = 0;
452 *cp++ = 0;
453 wep->weCnt |= WIN_LAST;
454 return 0;
455 }
456
457 /*
458 * Compare our filename to the one in the Win95 entry
459 * Returns the checksum or -1 if no match
460 */
461 int
winChkName(u_char * un,int unlen,struct winentry * wep,int chksum)462 winChkName(u_char *un, int unlen, struct winentry *wep, int chksum)
463 {
464 u_int8_t *cp;
465 int i;
466
467 /*
468 * First compare checksums
469 */
470 if (wep->weCnt&WIN_LAST)
471 chksum = wep->weChksum;
472 else if (chksum != wep->weChksum)
473 chksum = -1;
474 if (chksum == -1)
475 return -1;
476
477 /*
478 * Offset of this entry
479 */
480 i = ((wep->weCnt&WIN_CNT) - 1) * WIN_CHARS;
481 if ((unlen -= i) <= 0)
482 return -1;
483 un += i;
484
485 if ((wep->weCnt&WIN_LAST) && unlen > WIN_CHARS)
486 return -1;
487
488 /*
489 * Compare the name parts
490 */
491 for (cp = wep->wePart1, i = sizeof(wep->wePart1)/2; --i >= 0;) {
492 if (--unlen < 0) {
493 if (!*cp++ && !*cp)
494 return chksum;
495 return -1;
496 }
497 if (u2l[*cp++] != u2l[*un++] || *cp++)
498 return -1;
499 }
500 for (cp = wep->wePart2, i = sizeof(wep->wePart2)/2; --i >= 0;) {
501 if (--unlen < 0) {
502 if (!*cp++ && !*cp)
503 return chksum;
504 return -1;
505 }
506 if (u2l[*cp++] != u2l[*un++] || *cp++)
507 return -1;
508 }
509 for (cp = wep->wePart3, i = sizeof(wep->wePart3)/2; --i >= 0;) {
510 if (--unlen < 0) {
511 if (!*cp++ && !*cp)
512 return chksum;
513 return -1;
514 }
515 if (u2l[*cp++] != u2l[*un++] || *cp++)
516 return -1;
517 }
518 return chksum;
519 }
520
521 /*
522 * Compute the checksum of a DOS filename for Win95 use
523 */
524 u_int8_t
winChksum(u_int8_t * name)525 winChksum(u_int8_t *name)
526 {
527 int i;
528 u_int8_t s;
529
530 for (s = 0, i = 11; --i >= 0; s += *name++)
531 s = (s << 7)|(s >> 1);
532 return s;
533 }
534
535 /*
536 * Determine the number of slots necessary for Win95 names
537 */
538 int
winSlotCnt(u_char * un,int unlen)539 winSlotCnt(u_char *un, int unlen)
540 {
541 for (un += unlen; unlen > 0; unlen--)
542 if (*--un != ' ' && *un != '.')
543 break;
544 if (unlen > WIN_MAXLEN)
545 return 0;
546 return howmany(unlen, WIN_CHARS);
547 }
548