fat: Remove FAT Directory Bread message
[linux-2.6.git] / fs / udf / unicode.c
1 /*
2  * unicode.c
3  *
4  * PURPOSE
5  *      Routines for converting between UTF-8 and OSTA Compressed Unicode.
6  *      Also handles filename mangling
7  *
8  * DESCRIPTION
9  *      OSTA Compressed Unicode is explained in the OSTA UDF specification.
10  *              http://www.osta.org/
11  *      UTF-8 is explained in the IETF RFC XXXX.
12  *              ftp://ftp.internic.net/rfc/rfcxxxx.txt
13  *
14  * COPYRIGHT
15  *      This file is distributed under the terms of the GNU General Public
16  *      License (GPL). Copies of the GPL can be obtained from:
17  *              ftp://prep.ai.mit.edu/pub/gnu/GPL
18  *      Each contributing author retains all rights to their own work.
19  */
20
21 #include "udfdecl.h"
22
23 #include <linux/kernel.h>
24 #include <linux/string.h>       /* for memset */
25 #include <linux/nls.h>
26 #include <linux/crc-itu-t.h>
27 #include <linux/slab.h>
28
29 #include "udf_sb.h"
30
31 static int udf_translate_to_linux(uint8_t *, uint8_t *, int, uint8_t *, int);
32
33 static int udf_char_to_ustr(struct ustr *dest, const uint8_t *src, int strlen)
34 {
35         if ((!dest) || (!src) || (!strlen) || (strlen > UDF_NAME_LEN - 2))
36                 return 0;
37
38         memset(dest, 0, sizeof(struct ustr));
39         memcpy(dest->u_name, src, strlen);
40         dest->u_cmpID = 0x08;
41         dest->u_len = strlen;
42
43         return strlen;
44 }
45
46 /*
47  * udf_build_ustr
48  */
49 int udf_build_ustr(struct ustr *dest, dstring *ptr, int size)
50 {
51         int usesize;
52
53         if (!dest || !ptr || !size)
54                 return -1;
55         BUG_ON(size < 2);
56
57         usesize = min_t(size_t, ptr[size - 1], sizeof(dest->u_name));
58         usesize = min(usesize, size - 2);
59         dest->u_cmpID = ptr[0];
60         dest->u_len = usesize;
61         memcpy(dest->u_name, ptr + 1, usesize);
62         memset(dest->u_name + usesize, 0, sizeof(dest->u_name) - usesize);
63
64         return 0;
65 }
66
67 /*
68  * udf_build_ustr_exact
69  */
70 static int udf_build_ustr_exact(struct ustr *dest, dstring *ptr, int exactsize)
71 {
72         if ((!dest) || (!ptr) || (!exactsize))
73                 return -1;
74
75         memset(dest, 0, sizeof(struct ustr));
76         dest->u_cmpID = ptr[0];
77         dest->u_len = exactsize - 1;
78         memcpy(dest->u_name, ptr + 1, exactsize - 1);
79
80         return 0;
81 }
82
83 /*
84  * udf_ocu_to_utf8
85  *
86  * PURPOSE
87  *      Convert OSTA Compressed Unicode to the UTF-8 equivalent.
88  *
89  * PRE-CONDITIONS
90  *      utf                     Pointer to UTF-8 output buffer.
91  *      ocu                     Pointer to OSTA Compressed Unicode input buffer
92  *                              of size UDF_NAME_LEN bytes.
93  *                              both of type "struct ustr *"
94  *
95  * POST-CONDITIONS
96  *      <return>                Zero on success.
97  *
98  * HISTORY
99  *      November 12, 1997 - Andrew E. Mileski
100  *      Written, tested, and released.
101  */
102 int udf_CS0toUTF8(struct ustr *utf_o, const struct ustr *ocu_i)
103 {
104         const uint8_t *ocu;
105         uint8_t cmp_id, ocu_len;
106         int i;
107
108         ocu_len = ocu_i->u_len;
109         if (ocu_len == 0) {
110                 memset(utf_o, 0, sizeof(struct ustr));
111                 return 0;
112         }
113
114         cmp_id = ocu_i->u_cmpID;
115         if (cmp_id != 8 && cmp_id != 16) {
116                 memset(utf_o, 0, sizeof(struct ustr));
117                 printk(KERN_ERR "udf: unknown compression code (%d) stri=%s\n",
118                        cmp_id, ocu_i->u_name);
119                 return 0;
120         }
121
122         ocu = ocu_i->u_name;
123         utf_o->u_len = 0;
124         for (i = 0; (i < ocu_len) && (utf_o->u_len <= (UDF_NAME_LEN - 3));) {
125
126                 /* Expand OSTA compressed Unicode to Unicode */
127                 uint32_t c = ocu[i++];
128                 if (cmp_id == 16)
129                         c = (c << 8) | ocu[i++];
130
131                 /* Compress Unicode to UTF-8 */
132                 if (c < 0x80U)
133                         utf_o->u_name[utf_o->u_len++] = (uint8_t)c;
134                 else if (c < 0x800U) {
135                         utf_o->u_name[utf_o->u_len++] =
136                                                 (uint8_t)(0xc0 | (c >> 6));
137                         utf_o->u_name[utf_o->u_len++] =
138                                                 (uint8_t)(0x80 | (c & 0x3f));
139                 } else {
140                         utf_o->u_name[utf_o->u_len++] =
141                                                 (uint8_t)(0xe0 | (c >> 12));
142                         utf_o->u_name[utf_o->u_len++] =
143                                                 (uint8_t)(0x80 |
144                                                           ((c >> 6) & 0x3f));
145                         utf_o->u_name[utf_o->u_len++] =
146                                                 (uint8_t)(0x80 | (c & 0x3f));
147                 }
148         }
149         utf_o->u_cmpID = 8;
150
151         return utf_o->u_len;
152 }
153
154 /*
155  *
156  * udf_utf8_to_ocu
157  *
158  * PURPOSE
159  *      Convert UTF-8 to the OSTA Compressed Unicode equivalent.
160  *
161  * DESCRIPTION
162  *      This routine is only called by udf_lookup().
163  *
164  * PRE-CONDITIONS
165  *      ocu                     Pointer to OSTA Compressed Unicode output
166  *                              buffer of size UDF_NAME_LEN bytes.
167  *      utf                     Pointer to UTF-8 input buffer.
168  *      utf_len                 Length of UTF-8 input buffer in bytes.
169  *
170  * POST-CONDITIONS
171  *      <return>                Zero on success.
172  *
173  * HISTORY
174  *      November 12, 1997 - Andrew E. Mileski
175  *      Written, tested, and released.
176  */
177 static int udf_UTF8toCS0(dstring *ocu, struct ustr *utf, int length)
178 {
179         unsigned c, i, max_val, utf_char;
180         int utf_cnt, u_len;
181
182         memset(ocu, 0, sizeof(dstring) * length);
183         ocu[0] = 8;
184         max_val = 0xffU;
185
186 try_again:
187         u_len = 0U;
188         utf_char = 0U;
189         utf_cnt = 0U;
190         for (i = 0U; i < utf->u_len; i++) {
191                 c = (uint8_t)utf->u_name[i];
192
193                 /* Complete a multi-byte UTF-8 character */
194                 if (utf_cnt) {
195                         utf_char = (utf_char << 6) | (c & 0x3fU);
196                         if (--utf_cnt)
197                                 continue;
198                 } else {
199                         /* Check for a multi-byte UTF-8 character */
200                         if (c & 0x80U) {
201                                 /* Start a multi-byte UTF-8 character */
202                                 if ((c & 0xe0U) == 0xc0U) {
203                                         utf_char = c & 0x1fU;
204                                         utf_cnt = 1;
205                                 } else if ((c & 0xf0U) == 0xe0U) {
206                                         utf_char = c & 0x0fU;
207                                         utf_cnt = 2;
208                                 } else if ((c & 0xf8U) == 0xf0U) {
209                                         utf_char = c & 0x07U;
210                                         utf_cnt = 3;
211                                 } else if ((c & 0xfcU) == 0xf8U) {
212                                         utf_char = c & 0x03U;
213                                         utf_cnt = 4;
214                                 } else if ((c & 0xfeU) == 0xfcU) {
215                                         utf_char = c & 0x01U;
216                                         utf_cnt = 5;
217                                 } else {
218                                         goto error_out;
219                                 }
220                                 continue;
221                         } else {
222                                 /* Single byte UTF-8 character (most common) */
223                                 utf_char = c;
224                         }
225                 }
226
227                 /* Choose no compression if necessary */
228                 if (utf_char > max_val) {
229                         if (max_val == 0xffU) {
230                                 max_val = 0xffffU;
231                                 ocu[0] = (uint8_t)0x10U;
232                                 goto try_again;
233                         }
234                         goto error_out;
235                 }
236
237                 if (max_val == 0xffffU)
238                         ocu[++u_len] = (uint8_t)(utf_char >> 8);
239                 ocu[++u_len] = (uint8_t)(utf_char & 0xffU);
240         }
241
242         if (utf_cnt) {
243 error_out:
244                 ocu[++u_len] = '?';
245                 printk(KERN_DEBUG "udf: bad UTF-8 character\n");
246         }
247
248         ocu[length - 1] = (uint8_t)u_len + 1;
249
250         return u_len + 1;
251 }
252
253 static int udf_CS0toNLS(struct nls_table *nls, struct ustr *utf_o,
254                         const struct ustr *ocu_i)
255 {
256         const uint8_t *ocu;
257         uint8_t cmp_id, ocu_len;
258         int i, len;
259
260
261         ocu_len = ocu_i->u_len;
262         if (ocu_len == 0) {
263                 memset(utf_o, 0, sizeof(struct ustr));
264                 return 0;
265         }
266
267         cmp_id = ocu_i->u_cmpID;
268         if (cmp_id != 8 && cmp_id != 16) {
269                 memset(utf_o, 0, sizeof(struct ustr));
270                 printk(KERN_ERR "udf: unknown compression code (%d) stri=%s\n",
271                        cmp_id, ocu_i->u_name);
272                 return 0;
273         }
274
275         ocu = ocu_i->u_name;
276         utf_o->u_len = 0;
277         for (i = 0; (i < ocu_len) && (utf_o->u_len <= (UDF_NAME_LEN - 3));) {
278                 /* Expand OSTA compressed Unicode to Unicode */
279                 uint32_t c = ocu[i++];
280                 if (cmp_id == 16)
281                         c = (c << 8) | ocu[i++];
282
283                 len = nls->uni2char(c, &utf_o->u_name[utf_o->u_len],
284                                     UDF_NAME_LEN - utf_o->u_len);
285                 /* Valid character? */
286                 if (len >= 0)
287                         utf_o->u_len += len;
288                 else
289                         utf_o->u_name[utf_o->u_len++] = '?';
290         }
291         utf_o->u_cmpID = 8;
292
293         return utf_o->u_len;
294 }
295
296 static int udf_NLStoCS0(struct nls_table *nls, dstring *ocu, struct ustr *uni,
297                         int length)
298 {
299         int len;
300         unsigned i, max_val;
301         uint16_t uni_char;
302         int u_len;
303
304         memset(ocu, 0, sizeof(dstring) * length);
305         ocu[0] = 8;
306         max_val = 0xffU;
307
308 try_again:
309         u_len = 0U;
310         for (i = 0U; i < uni->u_len; i++) {
311                 len = nls->char2uni(&uni->u_name[i], uni->u_len - i, &uni_char);
312                 if (!len)
313                         continue;
314                 /* Invalid character, deal with it */
315                 if (len < 0) {
316                         len = 1;
317                         uni_char = '?';
318                 }
319
320                 if (uni_char > max_val) {
321                         max_val = 0xffffU;
322                         ocu[0] = (uint8_t)0x10U;
323                         goto try_again;
324                 }
325
326                 if (max_val == 0xffffU)
327                         ocu[++u_len] = (uint8_t)(uni_char >> 8);
328                 ocu[++u_len] = (uint8_t)(uni_char & 0xffU);
329                 i += len - 1;
330         }
331
332         ocu[length - 1] = (uint8_t)u_len + 1;
333         return u_len + 1;
334 }
335
336 int udf_get_filename(struct super_block *sb, uint8_t *sname, uint8_t *dname,
337                      int flen)
338 {
339         struct ustr *filename, *unifilename;
340         int len = 0;
341
342         filename = kmalloc(sizeof(struct ustr), GFP_NOFS);
343         if (!filename)
344                 return 0;
345
346         unifilename = kmalloc(sizeof(struct ustr), GFP_NOFS);
347         if (!unifilename)
348                 goto out1;
349
350         if (udf_build_ustr_exact(unifilename, sname, flen))
351                 goto out2;
352
353         if (UDF_QUERY_FLAG(sb, UDF_FLAG_UTF8)) {
354                 if (!udf_CS0toUTF8(filename, unifilename)) {
355                         udf_debug("Failed in udf_get_filename: sname = %s\n",
356                                   sname);
357                         goto out2;
358                 }
359         } else if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP)) {
360                 if (!udf_CS0toNLS(UDF_SB(sb)->s_nls_map, filename,
361                                   unifilename)) {
362                         udf_debug("Failed in udf_get_filename: sname = %s\n",
363                                   sname);
364                         goto out2;
365                 }
366         } else
367                 goto out2;
368
369         len = udf_translate_to_linux(dname, filename->u_name, filename->u_len,
370                                      unifilename->u_name, unifilename->u_len);
371 out2:
372         kfree(unifilename);
373 out1:
374         kfree(filename);
375         return len;
376 }
377
378 int udf_put_filename(struct super_block *sb, const uint8_t *sname,
379                      uint8_t *dname, int flen)
380 {
381         struct ustr unifilename;
382         int namelen;
383
384         if (!udf_char_to_ustr(&unifilename, sname, flen))
385                 return 0;
386
387         if (UDF_QUERY_FLAG(sb, UDF_FLAG_UTF8)) {
388                 namelen = udf_UTF8toCS0(dname, &unifilename, UDF_NAME_LEN);
389                 if (!namelen)
390                         return 0;
391         } else if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP)) {
392                 namelen = udf_NLStoCS0(UDF_SB(sb)->s_nls_map, dname,
393                                         &unifilename, UDF_NAME_LEN);
394                 if (!namelen)
395                         return 0;
396         } else
397                 return 0;
398
399         return namelen;
400 }
401
402 #define ILLEGAL_CHAR_MARK       '_'
403 #define EXT_MARK                '.'
404 #define CRC_MARK                '#'
405 #define EXT_SIZE                5
406
407 static int udf_translate_to_linux(uint8_t *newName, uint8_t *udfName,
408                                   int udfLen, uint8_t *fidName,
409                                   int fidNameLen)
410 {
411         int index, newIndex = 0, needsCRC = 0;
412         int extIndex = 0, newExtIndex = 0, hasExt = 0;
413         unsigned short valueCRC;
414         uint8_t curr;
415         const uint8_t hexChar[] = "0123456789ABCDEF";
416
417         if (udfName[0] == '.' &&
418             (udfLen == 1 || (udfLen == 2 && udfName[1] == '.'))) {
419                 needsCRC = 1;
420                 newIndex = udfLen;
421                 memcpy(newName, udfName, udfLen);
422         } else {
423                 for (index = 0; index < udfLen; index++) {
424                         curr = udfName[index];
425                         if (curr == '/' || curr == 0) {
426                                 needsCRC = 1;
427                                 curr = ILLEGAL_CHAR_MARK;
428                                 while (index + 1 < udfLen &&
429                                                 (udfName[index + 1] == '/' ||
430                                                  udfName[index + 1] == 0))
431                                         index++;
432                         }
433                         if (curr == EXT_MARK &&
434                                         (udfLen - index - 1) <= EXT_SIZE) {
435                                 if (udfLen == index + 1)
436                                         hasExt = 0;
437                                 else {
438                                         hasExt = 1;
439                                         extIndex = index;
440                                         newExtIndex = newIndex;
441                                 }
442                         }
443                         if (newIndex < 256)
444                                 newName[newIndex++] = curr;
445                         else
446                                 needsCRC = 1;
447                 }
448         }
449         if (needsCRC) {
450                 uint8_t ext[EXT_SIZE];
451                 int localExtIndex = 0;
452
453                 if (hasExt) {
454                         int maxFilenameLen;
455                         for (index = 0;
456                              index < EXT_SIZE && extIndex + index + 1 < udfLen;
457                              index++) {
458                                 curr = udfName[extIndex + index + 1];
459
460                                 if (curr == '/' || curr == 0) {
461                                         needsCRC = 1;
462                                         curr = ILLEGAL_CHAR_MARK;
463                                         while (extIndex + index + 2 < udfLen &&
464                                               (index + 1 < EXT_SIZE &&
465                                                 (udfName[extIndex + index + 2] == '/' ||
466                                                  udfName[extIndex + index + 2] == 0)))
467                                                 index++;
468                                 }
469                                 ext[localExtIndex++] = curr;
470                         }
471                         maxFilenameLen = 250 - localExtIndex;
472                         if (newIndex > maxFilenameLen)
473                                 newIndex = maxFilenameLen;
474                         else
475                                 newIndex = newExtIndex;
476                 } else if (newIndex > 250)
477                         newIndex = 250;
478                 newName[newIndex++] = CRC_MARK;
479                 valueCRC = crc_itu_t(0, fidName, fidNameLen);
480                 newName[newIndex++] = hexChar[(valueCRC & 0xf000) >> 12];
481                 newName[newIndex++] = hexChar[(valueCRC & 0x0f00) >> 8];
482                 newName[newIndex++] = hexChar[(valueCRC & 0x00f0) >> 4];
483                 newName[newIndex++] = hexChar[(valueCRC & 0x000f)];
484
485                 if (hasExt) {
486                         newName[newIndex++] = EXT_MARK;
487                         for (index = 0; index < localExtIndex; index++)
488                                 newName[newIndex++] = ext[index];
489                 }
490         }
491
492         return newIndex;
493 }