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