xref: /openbmc/linux/fs/udf/unicode.c (revision a1e58bbd)
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/udf_fs.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 
55 	memset(dest, 0, sizeof(struct ustr));
56 	usesize = (size > UDF_NAME_LEN) ? UDF_NAME_LEN : size;
57 	dest->u_cmpID = ptr[0];
58 	dest->u_len = ptr[size - 1];
59 	memcpy(dest->u_name, ptr + 1, usesize - 1);
60 
61 	return 0;
62 }
63 
64 /*
65  * udf_build_ustr_exact
66  */
67 static int udf_build_ustr_exact(struct ustr *dest, dstring *ptr, int exactsize)
68 {
69 	if ((!dest) || (!ptr) || (!exactsize))
70 		return -1;
71 
72 	memset(dest, 0, sizeof(struct ustr));
73 	dest->u_cmpID = ptr[0];
74 	dest->u_len = exactsize - 1;
75 	memcpy(dest->u_name, ptr + 1, exactsize - 1);
76 
77 	return 0;
78 }
79 
80 /*
81  * udf_ocu_to_utf8
82  *
83  * PURPOSE
84  *	Convert OSTA Compressed Unicode to the UTF-8 equivalent.
85  *
86  * DESCRIPTION
87  *	This routine is only called by udf_filldir().
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, struct ustr *ocu_i)
103 {
104 	uint8_t *ocu;
105 	uint32_t c;
106 	uint8_t cmp_id, ocu_len;
107 	int i;
108 
109 	ocu = ocu_i->u_name;
110 
111 	ocu_len = ocu_i->u_len;
112 	cmp_id = ocu_i->u_cmpID;
113 	utf_o->u_len = 0;
114 
115 	if (ocu_len == 0) {
116 		memset(utf_o, 0, sizeof(struct ustr));
117 		utf_o->u_cmpID = 0;
118 		utf_o->u_len = 0;
119 		return 0;
120 	}
121 
122 	if ((cmp_id != 8) && (cmp_id != 16)) {
123 		printk(KERN_ERR "udf: unknown compression code (%d) stri=%s\n",
124 		       cmp_id, ocu_i->u_name);
125 		return 0;
126 	}
127 
128 	for (i = 0; (i < ocu_len) && (utf_o->u_len <= (UDF_NAME_LEN - 3));) {
129 
130 		/* Expand OSTA compressed Unicode to Unicode */
131 		c = ocu[i++];
132 		if (cmp_id == 16)
133 			c = (c << 8) | ocu[i++];
134 
135 		/* Compress Unicode to UTF-8 */
136 		if (c < 0x80U) {
137 			utf_o->u_name[utf_o->u_len++] = (uint8_t)c;
138 		} else if (c < 0x800U) {
139 			utf_o->u_name[utf_o->u_len++] =
140 						(uint8_t)(0xc0 | (c >> 6));
141 			utf_o->u_name[utf_o->u_len++] =
142 						(uint8_t)(0x80 | (c & 0x3f));
143 		} else {
144 			utf_o->u_name[utf_o->u_len++] =
145 						(uint8_t)(0xe0 | (c >> 12));
146 			utf_o->u_name[utf_o->u_len++] =
147 						(uint8_t)(0x80 |
148 							  ((c >> 6) & 0x3f));
149 			utf_o->u_name[utf_o->u_len++] =
150 						(uint8_t)(0x80 | (c & 0x3f));
151 		}
152 	}
153 	utf_o->u_cmpID = 8;
154 
155 	return utf_o->u_len;
156 }
157 
158 /*
159  *
160  * udf_utf8_to_ocu
161  *
162  * PURPOSE
163  *	Convert UTF-8 to the OSTA Compressed Unicode equivalent.
164  *
165  * DESCRIPTION
166  *	This routine is only called by udf_lookup().
167  *
168  * PRE-CONDITIONS
169  *	ocu			Pointer to OSTA Compressed Unicode output
170  *				buffer of size UDF_NAME_LEN bytes.
171  *	utf			Pointer to UTF-8 input buffer.
172  *	utf_len			Length of UTF-8 input buffer in bytes.
173  *
174  * POST-CONDITIONS
175  *	<return>		Zero on success.
176  *
177  * HISTORY
178  *	November 12, 1997 - Andrew E. Mileski
179  *	Written, tested, and released.
180  */
181 static int udf_UTF8toCS0(dstring *ocu, struct ustr *utf, int length)
182 {
183 	unsigned c, i, max_val, utf_char;
184 	int utf_cnt, u_len;
185 
186 	memset(ocu, 0, sizeof(dstring) * length);
187 	ocu[0] = 8;
188 	max_val = 0xffU;
189 
190 try_again:
191 	u_len = 0U;
192 	utf_char = 0U;
193 	utf_cnt = 0U;
194 	for (i = 0U; i < utf->u_len; i++) {
195 		c = (uint8_t)utf->u_name[i];
196 
197 		/* Complete a multi-byte UTF-8 character */
198 		if (utf_cnt) {
199 			utf_char = (utf_char << 6) | (c & 0x3fU);
200 			if (--utf_cnt)
201 				continue;
202 		} else {
203 			/* Check for a multi-byte UTF-8 character */
204 			if (c & 0x80U) {
205 				/* Start a multi-byte UTF-8 character */
206 				if ((c & 0xe0U) == 0xc0U) {
207 					utf_char = c & 0x1fU;
208 					utf_cnt = 1;
209 				} else if ((c & 0xf0U) == 0xe0U) {
210 					utf_char = c & 0x0fU;
211 					utf_cnt = 2;
212 				} else if ((c & 0xf8U) == 0xf0U) {
213 					utf_char = c & 0x07U;
214 					utf_cnt = 3;
215 				} else if ((c & 0xfcU) == 0xf8U) {
216 					utf_char = c & 0x03U;
217 					utf_cnt = 4;
218 				} else if ((c & 0xfeU) == 0xfcU) {
219 					utf_char = c & 0x01U;
220 					utf_cnt = 5;
221 				} else {
222 					goto error_out;
223 				}
224 				continue;
225 			} else {
226 				/* Single byte UTF-8 character (most common) */
227 				utf_char = c;
228 			}
229 		}
230 
231 		/* Choose no compression if necessary */
232 		if (utf_char > max_val) {
233 			if (max_val == 0xffU) {
234 				max_val = 0xffffU;
235 				ocu[0] = (uint8_t)0x10U;
236 				goto try_again;
237 			}
238 			goto error_out;
239 		}
240 
241 		if (max_val == 0xffffU)
242 			ocu[++u_len] = (uint8_t)(utf_char >> 8);
243 		ocu[++u_len] = (uint8_t)(utf_char & 0xffU);
244 	}
245 
246 	if (utf_cnt) {
247 error_out:
248 		ocu[++u_len] = '?';
249 		printk(KERN_DEBUG "udf: bad UTF-8 character\n");
250 	}
251 
252 	ocu[length - 1] = (uint8_t)u_len + 1;
253 
254 	return u_len + 1;
255 }
256 
257 static int udf_CS0toNLS(struct nls_table *nls, struct ustr *utf_o,
258 			struct ustr *ocu_i)
259 {
260 	uint8_t *ocu;
261 	uint32_t c;
262 	uint8_t cmp_id, ocu_len;
263 	int i;
264 
265 	ocu = ocu_i->u_name;
266 
267 	ocu_len = ocu_i->u_len;
268 	cmp_id = ocu_i->u_cmpID;
269 	utf_o->u_len = 0;
270 
271 	if (ocu_len == 0) {
272 		memset(utf_o, 0, sizeof(struct ustr));
273 		utf_o->u_cmpID = 0;
274 		utf_o->u_len = 0;
275 		return 0;
276 	}
277 
278 	if ((cmp_id != 8) && (cmp_id != 16)) {
279 		printk(KERN_ERR "udf: unknown compression code (%d) stri=%s\n",
280 		       cmp_id, ocu_i->u_name);
281 		return 0;
282 	}
283 
284 	for (i = 0; (i < ocu_len) && (utf_o->u_len <= (UDF_NAME_LEN - 3));) {
285 		/* Expand OSTA compressed Unicode to Unicode */
286 		c = ocu[i++];
287 		if (cmp_id == 16)
288 			c = (c << 8) | ocu[i++];
289 
290 		utf_o->u_len += nls->uni2char(c, &utf_o->u_name[utf_o->u_len],
291 					      UDF_NAME_LEN - utf_o->u_len);
292 	}
293 	utf_o->u_cmpID = 8;
294 
295 	return utf_o->u_len;
296 }
297 
298 static int udf_NLStoCS0(struct nls_table *nls, dstring *ocu, struct ustr *uni,
299 			int length)
300 {
301 	unsigned len, i, max_val;
302 	uint16_t uni_char;
303 	int u_len;
304 
305 	memset(ocu, 0, sizeof(dstring) * length);
306 	ocu[0] = 8;
307 	max_val = 0xffU;
308 
309 try_again:
310 	u_len = 0U;
311 	for (i = 0U; i < uni->u_len; i++) {
312 		len = nls->char2uni(&uni->u_name[i], uni->u_len - i, &uni_char);
313 		if (len <= 0)
314 			continue;
315 
316 		if (uni_char > max_val) {
317 			max_val = 0xffffU;
318 			ocu[0] = (uint8_t)0x10U;
319 			goto try_again;
320 		}
321 
322 		if (max_val == 0xffffU)
323 			ocu[++u_len] = (uint8_t)(uni_char >> 8);
324 		ocu[++u_len] = (uint8_t)(uni_char & 0xffU);
325 		i += len - 1;
326 	}
327 
328 	ocu[length - 1] = (uint8_t)u_len + 1;
329 	return u_len + 1;
330 }
331 
332 int udf_get_filename(struct super_block *sb, uint8_t *sname, uint8_t *dname,
333 		     int flen)
334 {
335 	struct ustr filename, unifilename;
336 	int len;
337 
338 	if (udf_build_ustr_exact(&unifilename, sname, flen))
339 		return 0;
340 
341 	if (UDF_QUERY_FLAG(sb, UDF_FLAG_UTF8)) {
342 		if (!udf_CS0toUTF8(&filename, &unifilename)) {
343 			udf_debug("Failed in udf_get_filename: sname = %s\n",
344 				  sname);
345 			return 0;
346 		}
347 	} else if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP)) {
348 		if (!udf_CS0toNLS(UDF_SB(sb)->s_nls_map, &filename,
349 				  &unifilename)) {
350 			udf_debug("Failed in udf_get_filename: sname = %s\n",
351 				  sname);
352 			return 0;
353 		}
354 	} else
355 		return 0;
356 
357 	len = udf_translate_to_linux(dname, filename.u_name, filename.u_len,
358 				     unifilename.u_name, unifilename.u_len);
359 	if (len)
360 		return len;
361 
362 	return 0;
363 }
364 
365 int udf_put_filename(struct super_block *sb, const uint8_t *sname,
366 		     uint8_t *dname, int flen)
367 {
368 	struct ustr unifilename;
369 	int namelen;
370 
371 	if (!udf_char_to_ustr(&unifilename, sname, flen))
372 		return 0;
373 
374 	if (UDF_QUERY_FLAG(sb, UDF_FLAG_UTF8)) {
375 		namelen = udf_UTF8toCS0(dname, &unifilename, UDF_NAME_LEN);
376 		if (!namelen)
377 			return 0;
378 	} else if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP)) {
379 		namelen = udf_NLStoCS0(UDF_SB(sb)->s_nls_map, dname,
380 					&unifilename, UDF_NAME_LEN);
381 		if (!namelen)
382 			return 0;
383 	} else
384 		return 0;
385 
386 	return namelen;
387 }
388 
389 #define ILLEGAL_CHAR_MARK	'_'
390 #define EXT_MARK		'.'
391 #define CRC_MARK		'#'
392 #define EXT_SIZE 		5
393 
394 static int udf_translate_to_linux(uint8_t *newName, uint8_t *udfName,
395 				  int udfLen, uint8_t *fidName,
396 				  int fidNameLen)
397 {
398 	int index, newIndex = 0, needsCRC = 0;
399 	int extIndex = 0, newExtIndex = 0, hasExt = 0;
400 	unsigned short valueCRC;
401 	uint8_t curr;
402 	const uint8_t hexChar[] = "0123456789ABCDEF";
403 
404 	if (udfName[0] == '.' &&
405 	    (udfLen == 1 || (udfLen == 2 && udfName[1] == '.'))) {
406 		needsCRC = 1;
407 		newIndex = udfLen;
408 		memcpy(newName, udfName, udfLen);
409 	} else {
410 		for (index = 0; index < udfLen; index++) {
411 			curr = udfName[index];
412 			if (curr == '/' || curr == 0) {
413 				needsCRC = 1;
414 				curr = ILLEGAL_CHAR_MARK;
415 				while (index + 1 < udfLen &&
416 						(udfName[index + 1] == '/' ||
417 						 udfName[index + 1] == 0))
418 					index++;
419 			}
420 			if (curr == EXT_MARK &&
421 					(udfLen - index - 1) <= EXT_SIZE) {
422 				if (udfLen == index + 1)
423 					hasExt = 0;
424 				else {
425 					hasExt = 1;
426 					extIndex = index;
427 					newExtIndex = newIndex;
428 				}
429 			}
430 			if (newIndex < 256)
431 				newName[newIndex++] = curr;
432 			else
433 				needsCRC = 1;
434 		}
435 	}
436 	if (needsCRC) {
437 		uint8_t ext[EXT_SIZE];
438 		int localExtIndex = 0;
439 
440 		if (hasExt) {
441 			int maxFilenameLen;
442 			for (index = 0;
443 			     index < EXT_SIZE && extIndex + index + 1 < udfLen;
444 			     index++) {
445 				curr = udfName[extIndex + index + 1];
446 
447 				if (curr == '/' || curr == 0) {
448 					needsCRC = 1;
449 					curr = ILLEGAL_CHAR_MARK;
450 					while (extIndex + index + 2 < udfLen &&
451 					      (index + 1 < EXT_SIZE &&
452 						(udfName[extIndex + index + 2] == '/' ||
453 						 udfName[extIndex + index + 2] == 0)))
454 						index++;
455 				}
456 				ext[localExtIndex++] = curr;
457 			}
458 			maxFilenameLen = 250 - localExtIndex;
459 			if (newIndex > maxFilenameLen)
460 				newIndex = maxFilenameLen;
461 			else
462 				newIndex = newExtIndex;
463 		} else if (newIndex > 250)
464 			newIndex = 250;
465 		newName[newIndex++] = CRC_MARK;
466 		valueCRC = udf_crc(fidName, fidNameLen, 0);
467 		newName[newIndex++] = hexChar[(valueCRC & 0xf000) >> 12];
468 		newName[newIndex++] = hexChar[(valueCRC & 0x0f00) >> 8];
469 		newName[newIndex++] = hexChar[(valueCRC & 0x00f0) >> 4];
470 		newName[newIndex++] = hexChar[(valueCRC & 0x000f)];
471 
472 		if (hasExt) {
473 			newName[newIndex++] = EXT_MARK;
474 			for (index = 0; index < localExtIndex; index++)
475 				newName[newIndex++] = ext[index];
476 		}
477 	}
478 
479 	return newIndex;
480 }
481