source: mainline/uspace/srv/fs/fat/fat_dentry.c@ 2a08005

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 2a08005 was a7a7f8c, checked in by Vojtech Horky <vojtechhorky@…>, 14 years ago

Merge mainline changes
  • Property mode set to 100644
File size: 9.0 KB
Line 
1/*
2 * Copyright (c) 2008 Jakub Jermar
3 * Copyright (c) 2011 Oleg Romanenko
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * - Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * - Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * - The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30/** @addtogroup fs
31 * @{
32 */
33
34/**
35 * @file fat_dentry.c
36 * @brief Functions that work with FAT directory entries.
37 */
38
39#include "fat_dentry.h"
40#include <ctype.h>
41#include <str.h>
42#include <errno.h>
43#include <byteorder.h>
44#include <assert.h>
45#include <unistd.h>
46
47/** Compare path component with the name read from the dentry.
48 *
49 * This function compares the path component with the name read from the dentry.
50 * The comparison is case insensitive and tolerates a mismatch on the trailing
51 * dot character at the end of the name (i.e. when there is a dot, but no
52 * extension).
53 *
54 * @param name Node name read from the dentry.
55 * @param component Path component.
56 *
57 * @return Zero on match, non-zero otherwise.
58 */
59int fat_dentry_namecmp(char *name, const char *component)
60{
61 int rc;
62 size_t size;
63
64 if (!(rc = stricmp(name, component)))
65 return rc;
66 if (!str_chr(name, '.')) {
67 /*
68 * There is no '.' in the name, so we know that there is enough
69 * space for appending an extra '.' to name.
70 */
71 size = str_size(name);
72 name[size] = '.';
73 name[size + 1] = '\0';
74 rc = stricmp(name, component);
75 }
76 return rc;
77}
78
79void fat_dentry_name_get(const fat_dentry_t *d, char *buf)
80{
81 unsigned int i;
82
83 for (i = 0; i < FAT_NAME_LEN; i++) {
84 if (d->name[i] == FAT_PAD)
85 break;
86
87 if (d->name[i] == FAT_DENTRY_E5_ESC)
88 *buf++ = 0xe5;
89 else {
90 if (d->lcase & FAT_LCASE_LOWER_NAME)
91 *buf++ = tolower(d->name[i]);
92 else
93 *buf++ = d->name[i];
94 }
95 }
96
97 if (d->ext[0] != FAT_PAD)
98 *buf++ = '.';
99
100 for (i = 0; i < FAT_EXT_LEN; i++) {
101 if (d->ext[i] == FAT_PAD) {
102 *buf = '\0';
103 return;
104 }
105
106 if (d->ext[i] == FAT_DENTRY_E5_ESC)
107 *buf++ = 0xe5;
108 else {
109 if (d->lcase & FAT_LCASE_LOWER_EXT)
110 *buf++ = tolower(d->ext[i]);
111 else
112 *buf++ = d->ext[i];
113 }
114 }
115
116 *buf = '\0';
117}
118
119void fat_dentry_name_set(fat_dentry_t *d, const char *name)
120{
121 unsigned int i;
122 const char fake_ext[] = " ";
123 bool lower_name = true;
124 bool lower_ext = true;
125
126 for (i = 0; i < FAT_NAME_LEN; i++) {
127 switch ((uint8_t) *name) {
128 case 0xe5:
129 d->name[i] = FAT_DENTRY_E5_ESC;
130 name++;
131 break;
132 case '\0':
133 case '.':
134 d->name[i] = FAT_PAD;
135 break;
136 default:
137 if (isalpha(*name)) {
138 if (!islower(*name))
139 lower_name = false;
140 }
141
142 d->name[i] = toupper(*name++);
143 break;
144 }
145 }
146
147 if (*name++ != '.')
148 name = fake_ext;
149
150 for (i = 0; i < FAT_EXT_LEN; i++) {
151 switch ((uint8_t) *name) {
152 case 0xe5:
153 d->ext[i] = FAT_DENTRY_E5_ESC;
154 name++;
155 break;
156 case '\0':
157 d->ext[i] = FAT_PAD;
158 break;
159 default:
160 if (isalpha(*name)) {
161 if (!islower(*name))
162 lower_ext = false;
163 }
164
165 d->ext[i] = toupper(*name++);
166 break;
167 }
168 }
169
170 if (lower_name)
171 d->lcase |= FAT_LCASE_LOWER_NAME;
172 else
173 d->lcase &= ~FAT_LCASE_LOWER_NAME;
174
175 if (lower_ext)
176 d->lcase |= FAT_LCASE_LOWER_EXT;
177 else
178 d->lcase &= ~FAT_LCASE_LOWER_EXT;
179}
180
181fat_dentry_clsf_t fat_classify_dentry(const fat_dentry_t *d)
182{
183 if (d->attr == FAT_ATTR_LFN) {
184 /* long name entry */
185 if (FAT_LFN_ORDER(d) & FAT_LFN_ERASED)
186 return FAT_DENTRY_FREE;
187 else
188 return FAT_DENTRY_LFN;
189 }
190 if (d->attr & FAT_ATTR_VOLLABEL) {
191 /* volume label entry */
192 return FAT_DENTRY_SKIP;
193 }
194 if (d->name[0] == FAT_DENTRY_ERASED) {
195 /* not-currently-used entry */
196 return FAT_DENTRY_FREE;
197 }
198 if (d->name[0] == FAT_DENTRY_UNUSED) {
199 /* never used entry */
200 return FAT_DENTRY_LAST;
201 }
202 if (d->name[0] == FAT_DENTRY_DOT) {
203 /*
204 * Most likely '.' or '..'.
205 * It cannot occur in a regular file name.
206 */
207 return FAT_DENTRY_SKIP;
208 }
209 return FAT_DENTRY_VALID;
210}
211
212/** Compute checksum of Node name.
213 *
214 * Returns an unsigned byte checksum computed on an unsigned byte
215 * array. The array must be 11 bytes long and is assumed to contain
216 * a name stored in the format of a MS-DOS directory entry.
217 *
218 * @param name Node name read from the dentry.
219 *
220 * @return An 8-bit unsigned checksum of the name.
221 */
222uint8_t fat_dentry_chksum(uint8_t *name)
223{
224 uint8_t i, sum = 0;
225
226 for (i = 0; i < (FAT_NAME_LEN + FAT_EXT_LEN); i++)
227 sum = ((sum & 1) ? 0x80 : 0) + (sum >> 1) + name[i];
228
229 return sum;
230}
231
232/** Get number of bytes in a string with size limit.
233 *
234 * @param str NULL-terminated (or not) string.
235 * @param size Maximum number of bytes to consider.
236 *
237 * @return Number of bytes in string (without 0 and ff).
238 *
239 */
240size_t fat_lfn_str_nlength(const uint16_t *str, size_t size)
241{
242 size_t offset = 0;
243
244 while (offset < size) {
245 if (str[offset] == 0 || str[offset] == FAT_LFN_PAD)
246 break;
247 offset++;
248 }
249 return offset;
250}
251
252/** Get number of bytes in a FAT long entry occuped by characters.
253 *
254 * @param d FAT long entry.
255 *
256 * @return Number of bytes.
257 *
258 */
259size_t fat_lfn_size(const fat_dentry_t *d)
260{
261 size_t size = 0;
262
263 size += fat_lfn_str_nlength(FAT_LFN_PART1(d), FAT_LFN_PART1_SIZE);
264 size += fat_lfn_str_nlength(FAT_LFN_PART2(d), FAT_LFN_PART2_SIZE);
265 size += fat_lfn_str_nlength(FAT_LFN_PART3(d), FAT_LFN_PART3_SIZE);
266
267 return size;
268}
269
270size_t fat_lfn_get_entry(const fat_dentry_t *d, uint16_t *dst, size_t *offset)
271{
272 int i;
273 for (i = FAT_LFN_PART3_SIZE - 1; i >= 0 && *offset > 0; i--) {
274 if (d->lfn.part3[i] == 0 || d->lfn.part3[i] == FAT_LFN_PAD)
275 continue;
276 (*offset)--;
277 dst[(*offset)] = uint16_t_le2host(d->lfn.part3[i]);
278 }
279 for (i = FAT_LFN_PART2_SIZE - 1; i >= 0 && *offset > 0; i--) {
280 if (d->lfn.part2[i] == 0 || d->lfn.part2[i] == FAT_LFN_PAD)
281 continue;
282 (*offset)--;
283 dst[(*offset)] = uint16_t_le2host(d->lfn.part2[i]);
284 }
285 for (i = FAT_LFN_PART1_SIZE - 1; i >= 0 && *offset > 0; i--) {
286 if (d->lfn.part1[i] == 0 || d->lfn.part1[i] == FAT_LFN_PAD)
287 continue;
288 (*offset)--;
289 dst[(*offset)] = uint16_t_le2host(d->lfn.part1[i]);
290 }
291 return *offset;
292}
293
294size_t fat_lfn_set_entry(const uint16_t *src, size_t *offset, size_t size,
295 fat_dentry_t *d)
296{
297 size_t idx;
298 for (idx = 0; idx < FAT_LFN_PART1_SIZE; idx++) {
299 if (*offset < size) {
300 d->lfn.part1[idx] = host2uint16_t_le(src[*offset]);
301 (*offset)++;
302 } else
303 d->lfn.part1[idx] = FAT_LFN_PAD;
304 }
305 for (idx = 0; idx < FAT_LFN_PART2_SIZE; idx++) {
306 if (*offset < size) {
307 d->lfn.part2[idx] = host2uint16_t_le(src[*offset]);
308 (*offset)++;
309 } else
310 d->lfn.part2[idx] = FAT_LFN_PAD;
311 }
312 for (idx = 0; idx < FAT_LFN_PART3_SIZE; idx++) {
313 if (*offset < size) {
314 d->lfn.part3[idx] = host2uint16_t_le(src[*offset]);
315 (*offset)++;
316 } else
317 d->lfn.part3[idx] = FAT_LFN_PAD;
318 }
319
320 if (src[*offset] == 0)
321 offset++;
322 FAT_LFN_ATTR(d) = FAT_ATTR_LFN;
323 d->lfn.type = 0;
324 d->lfn.firstc_lo = 0;
325
326 return *offset;
327}
328
329void str_to_ascii(char *dst, const char *src, size_t count, uint8_t pad)
330{
331 wchar_t ch;
332 size_t off = 0;
333 size_t i = 0;
334
335 while (i < count) {
336 if ((ch = str_decode(src, &off, STR_NO_LIMIT)) != 0) {
337 if (ascii_check(ch) && IS_D_CHAR(ch))
338 *dst = toupper(ch);
339 else
340 *dst = pad;
341 } else
342 break;
343
344 dst++;
345 i++;
346 }
347 *dst = '\0';
348}
349
350bool fat_valid_name(const char *name)
351{
352 wchar_t ch;
353 size_t offset=0;
354 bool result = true;
355
356 while ((ch = str_decode(name, &offset, STR_NO_LIMIT)) != 0) {
357 if (str_chr(FAT_STOP_CHARS, ch) != NULL) {
358 result = false;
359 break;
360 }
361 }
362 return result;
363}
364
365bool fat_valid_short_name(const char *name)
366{
367 unsigned int i;
368 unsigned int dot = 0;
369 bool dot_found = false;
370
371 for (i = 0; name[i]; i++) {
372 if (name[i] == '.') {
373 if (dot_found) {
374 return false;
375 } else {
376 dot_found = true;
377 dot = i;
378 }
379 } else {
380 if (!IS_D_CHAR(name[i]))
381 return false;
382 }
383 }
384
385 if (dot_found) {
386 if (dot > FAT_NAME_LEN)
387 return false;
388 if (i - dot > FAT_EXT_LEN + 1)
389 return false;
390 } else {
391 if (i > FAT_NAME_LEN)
392 return false;
393 }
394
395 return true;
396}
397
398size_t utf16_length(const uint16_t *wstr)
399{
400 size_t len = 0;
401
402 while (*wstr++ != 0)
403 len++;
404
405 return len;
406}
407
408/**
409 * @}
410 */
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