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
31static int udf_translate_to_linux(uint8_t *, int, uint8_t *, int, uint8_t *,
32				  int);
33
34static int udf_char_to_ustr(struct ustr *dest, const uint8_t *src, int strlen)
35{
36	if ((!dest) || (!src) || (!strlen) || (strlen > UDF_NAME_LEN - 2))
37		return 0;
38
39	memset(dest, 0, sizeof(struct ustr));
40	memcpy(dest->u_name, src, strlen);
41	dest->u_cmpID = 0x08;
42	dest->u_len = strlen;
43
44	return strlen;
45}
46
47/*
48 * udf_build_ustr
49 */
50int udf_build_ustr(struct ustr *dest, dstring *ptr, int size)
51{
52	int usesize;
53
54	if (!dest || !ptr || !size)
55		return -1;
56	BUG_ON(size < 2);
57
58	usesize = min_t(size_t, ptr[size - 1], sizeof(dest->u_name));
59	usesize = min(usesize, size - 2);
60	dest->u_cmpID = ptr[0];
61	dest->u_len = usesize;
62	memcpy(dest->u_name, ptr + 1, usesize);
63	memset(dest->u_name + usesize, 0, sizeof(dest->u_name) - usesize);
64
65	return 0;
66}
67
68/*
69 * udf_build_ustr_exact
70 */
71static int udf_build_ustr_exact(struct ustr *dest, dstring *ptr, int exactsize)
72{
73	if ((!dest) || (!ptr) || (!exactsize))
74		return -1;
75
76	memset(dest, 0, sizeof(struct ustr));
77	dest->u_cmpID = ptr[0];
78	dest->u_len = exactsize - 1;
79	memcpy(dest->u_name, ptr + 1, exactsize - 1);
80
81	return 0;
82}
83
84/*
85 * udf_ocu_to_utf8
86 *
87 * PURPOSE
88 *	Convert OSTA Compressed Unicode to the UTF-8 equivalent.
89 *
90 * PRE-CONDITIONS
91 *	utf			Pointer to UTF-8 output buffer.
92 *	ocu			Pointer to OSTA Compressed Unicode input buffer
93 *				of size UDF_NAME_LEN bytes.
94 * 				both of type "struct ustr *"
95 *
96 * POST-CONDITIONS
97 *	<return>		Zero on success.
98 *
99 * HISTORY
100 *	November 12, 1997 - Andrew E. Mileski
101 *	Written, tested, and released.
102 */
103int udf_CS0toUTF8(struct ustr *utf_o, const struct ustr *ocu_i)
104{
105	const uint8_t *ocu;
106	uint8_t cmp_id, ocu_len;
107	int i;
108
109	ocu_len = ocu_i->u_len;
110	if (ocu_len == 0) {
111		memset(utf_o, 0, sizeof(struct ustr));
112		return 0;
113	}
114
115	cmp_id = ocu_i->u_cmpID;
116	if (cmp_id != 8 && cmp_id != 16) {
117		memset(utf_o, 0, sizeof(struct ustr));
118		pr_err("unknown compression code (%d) stri=%s\n",
119		       cmp_id, ocu_i->u_name);
120		return 0;
121	}
122
123	ocu = ocu_i->u_name;
124	utf_o->u_len = 0;
125	for (i = 0; (i < ocu_len) && (utf_o->u_len <= (UDF_NAME_LEN - 3));) {
126
127		/* Expand OSTA compressed Unicode to Unicode */
128		uint32_t c = ocu[i++];
129		if (cmp_id == 16)
130			c = (c << 8) | ocu[i++];
131
132		/* Compress Unicode to UTF-8 */
133		if (c < 0x80U)
134			utf_o->u_name[utf_o->u_len++] = (uint8_t)c;
135		else if (c < 0x800U) {
136			if (utf_o->u_len > (UDF_NAME_LEN - 4))
137				break;
138			utf_o->u_name[utf_o->u_len++] =
139						(uint8_t)(0xc0 | (c >> 6));
140			utf_o->u_name[utf_o->u_len++] =
141						(uint8_t)(0x80 | (c & 0x3f));
142		} else {
143			if (utf_o->u_len > (UDF_NAME_LEN - 5))
144				break;
145			utf_o->u_name[utf_o->u_len++] =
146						(uint8_t)(0xe0 | (c >> 12));
147			utf_o->u_name[utf_o->u_len++] =
148						(uint8_t)(0x80 |
149							  ((c >> 6) & 0x3f));
150			utf_o->u_name[utf_o->u_len++] =
151						(uint8_t)(0x80 | (c & 0x3f));
152		}
153	}
154	utf_o->u_cmpID = 8;
155
156	return utf_o->u_len;
157}
158
159/*
160 *
161 * udf_utf8_to_ocu
162 *
163 * PURPOSE
164 *	Convert UTF-8 to the OSTA Compressed Unicode equivalent.
165 *
166 * DESCRIPTION
167 *	This routine is only called by udf_lookup().
168 *
169 * PRE-CONDITIONS
170 *	ocu			Pointer to OSTA Compressed Unicode output
171 *				buffer of size UDF_NAME_LEN bytes.
172 *	utf			Pointer to UTF-8 input buffer.
173 *	utf_len			Length of UTF-8 input buffer in bytes.
174 *
175 * POST-CONDITIONS
176 *	<return>		Zero on success.
177 *
178 * HISTORY
179 *	November 12, 1997 - Andrew E. Mileski
180 *	Written, tested, and released.
181 */
182static int udf_UTF8toCS0(dstring *ocu, struct ustr *utf, int length)
183{
184	unsigned c, i, max_val, utf_char;
185	int utf_cnt, u_len, u_ch;
186
187	memset(ocu, 0, sizeof(dstring) * length);
188	ocu[0] = 8;
189	max_val = 0xffU;
190	u_ch = 1;
191
192try_again:
193	u_len = 0U;
194	utf_char = 0U;
195	utf_cnt = 0U;
196	for (i = 0U; i < utf->u_len; i++) {
197		/* Name didn't fit? */
198		if (u_len + 1 + u_ch >= length)
199			return 0;
200
201		c = (uint8_t)utf->u_name[i];
202
203		/* Complete a multi-byte UTF-8 character */
204		if (utf_cnt) {
205			utf_char = (utf_char << 6) | (c & 0x3fU);
206			if (--utf_cnt)
207				continue;
208		} else {
209			/* Check for a multi-byte UTF-8 character */
210			if (c & 0x80U) {
211				/* Start a multi-byte UTF-8 character */
212				if ((c & 0xe0U) == 0xc0U) {
213					utf_char = c & 0x1fU;
214					utf_cnt = 1;
215				} else if ((c & 0xf0U) == 0xe0U) {
216					utf_char = c & 0x0fU;
217					utf_cnt = 2;
218				} else if ((c & 0xf8U) == 0xf0U) {
219					utf_char = c & 0x07U;
220					utf_cnt = 3;
221				} else if ((c & 0xfcU) == 0xf8U) {
222					utf_char = c & 0x03U;
223					utf_cnt = 4;
224				} else if ((c & 0xfeU) == 0xfcU) {
225					utf_char = c & 0x01U;
226					utf_cnt = 5;
227				} else {
228					goto error_out;
229				}
230				continue;
231			} else {
232				/* Single byte UTF-8 character (most common) */
233				utf_char = c;
234			}
235		}
236
237		/* Choose no compression if necessary */
238		if (utf_char > max_val) {
239			if (max_val == 0xffU) {
240				max_val = 0xffffU;
241				ocu[0] = (uint8_t)0x10U;
242				u_ch = 2;
243				goto try_again;
244			}
245			goto error_out;
246		}
247
248		if (max_val == 0xffffU)
249			ocu[++u_len] = (uint8_t)(utf_char >> 8);
250		ocu[++u_len] = (uint8_t)(utf_char & 0xffU);
251	}
252
253	if (utf_cnt) {
254error_out:
255		ocu[++u_len] = '?';
256		printk(KERN_DEBUG pr_fmt("bad UTF-8 character\n"));
257	}
258
259	ocu[length - 1] = (uint8_t)u_len + 1;
260
261	return u_len + 1;
262}
263
264static int udf_CS0toNLS(struct nls_table *nls, struct ustr *utf_o,
265			const struct ustr *ocu_i)
266{
267	const uint8_t *ocu;
268	uint8_t cmp_id, ocu_len;
269	int i, len;
270
271
272	ocu_len = ocu_i->u_len;
273	if (ocu_len == 0) {
274		memset(utf_o, 0, sizeof(struct ustr));
275		return 0;
276	}
277
278	cmp_id = ocu_i->u_cmpID;
279	if (cmp_id != 8 && cmp_id != 16) {
280		memset(utf_o, 0, sizeof(struct ustr));
281		pr_err("unknown compression code (%d) stri=%s\n",
282		       cmp_id, ocu_i->u_name);
283		return 0;
284	}
285
286	ocu = ocu_i->u_name;
287	utf_o->u_len = 0;
288	for (i = 0; (i < ocu_len) && (utf_o->u_len <= (UDF_NAME_LEN - 3));) {
289		/* Expand OSTA compressed Unicode to Unicode */
290		uint32_t c = ocu[i++];
291		if (cmp_id == 16)
292			c = (c << 8) | ocu[i++];
293
294		len = nls->uni2char(c, &utf_o->u_name[utf_o->u_len],
295				    UDF_NAME_LEN - 2 - utf_o->u_len);
296		/* Valid character? */
297		if (len >= 0)
298			utf_o->u_len += len;
299		else
300			utf_o->u_name[utf_o->u_len++] = '?';
301	}
302	utf_o->u_cmpID = 8;
303
304	return utf_o->u_len;
305}
306
307static int udf_NLStoCS0(struct nls_table *nls, dstring *ocu, struct ustr *uni,
308			int length)
309{
310	int len;
311	unsigned i, max_val;
312	uint16_t uni_char;
313	int u_len, u_ch;
314
315	memset(ocu, 0, sizeof(dstring) * length);
316	ocu[0] = 8;
317	max_val = 0xffU;
318	u_ch = 1;
319
320try_again:
321	u_len = 0U;
322	for (i = 0U; i < uni->u_len; i++) {
323		/* Name didn't fit? */
324		if (u_len + 1 + u_ch >= length)
325			return 0;
326		len = nls->char2uni(&uni->u_name[i], uni->u_len - i, &uni_char);
327		if (!len)
328			continue;
329		/* Invalid character, deal with it */
330		if (len < 0) {
331			len = 1;
332			uni_char = '?';
333		}
334
335		if (uni_char > max_val) {
336			max_val = 0xffffU;
337			ocu[0] = (uint8_t)0x10U;
338			u_ch = 2;
339			goto try_again;
340		}
341
342		if (max_val == 0xffffU)
343			ocu[++u_len] = (uint8_t)(uni_char >> 8);
344		ocu[++u_len] = (uint8_t)(uni_char & 0xffU);
345		i += len - 1;
346	}
347
348	ocu[length - 1] = (uint8_t)u_len + 1;
349	return u_len + 1;
350}
351
352int udf_get_filename(struct super_block *sb, uint8_t *sname, int slen,
353		     uint8_t *dname, int dlen)
354{
355	struct ustr *filename, *unifilename;
356	int len = 0;
357
358	filename = kmalloc(sizeof(struct ustr), GFP_NOFS);
359	if (!filename)
360		return 0;
361
362	unifilename = kmalloc(sizeof(struct ustr), GFP_NOFS);
363	if (!unifilename)
364		goto out1;
365
366	if (udf_build_ustr_exact(unifilename, sname, slen))
367		goto out2;
368
369	if (UDF_QUERY_FLAG(sb, UDF_FLAG_UTF8)) {
370		if (!udf_CS0toUTF8(filename, unifilename)) {
371			udf_debug("Failed in udf_get_filename: sname = %s\n",
372				  sname);
373			goto out2;
374		}
375	} else if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP)) {
376		if (!udf_CS0toNLS(UDF_SB(sb)->s_nls_map, filename,
377				  unifilename)) {
378			udf_debug("Failed in udf_get_filename: sname = %s\n",
379				  sname);
380			goto out2;
381		}
382	} else
383		goto out2;
384
385	len = udf_translate_to_linux(dname, dlen,
386				     filename->u_name, filename->u_len,
387				     unifilename->u_name, unifilename->u_len);
388out2:
389	kfree(unifilename);
390out1:
391	kfree(filename);
392	return len;
393}
394
395int udf_put_filename(struct super_block *sb, const uint8_t *sname,
396		     uint8_t *dname, int flen)
397{
398	struct ustr unifilename;
399	int namelen;
400
401	if (!udf_char_to_ustr(&unifilename, sname, flen))
402		return 0;
403
404	if (UDF_QUERY_FLAG(sb, UDF_FLAG_UTF8)) {
405		namelen = udf_UTF8toCS0(dname, &unifilename, UDF_NAME_LEN);
406		if (!namelen)
407			return 0;
408	} else if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP)) {
409		namelen = udf_NLStoCS0(UDF_SB(sb)->s_nls_map, dname,
410					&unifilename, UDF_NAME_LEN);
411		if (!namelen)
412			return 0;
413	} else
414		return 0;
415
416	return namelen;
417}
418
419#define ILLEGAL_CHAR_MARK	'_'
420#define EXT_MARK		'.'
421#define CRC_MARK		'#'
422#define EXT_SIZE 		5
423/* Number of chars we need to store generated CRC to make filename unique */
424#define CRC_LEN			5
425
426static int udf_translate_to_linux(uint8_t *newName, int newLen,
427				  uint8_t *udfName, int udfLen,
428				  uint8_t *fidName, int fidNameLen)
429{
430	int index, newIndex = 0, needsCRC = 0;
431	int extIndex = 0, newExtIndex = 0, hasExt = 0;
432	unsigned short valueCRC;
433	uint8_t curr;
434
435	if (udfName[0] == '.' &&
436	    (udfLen == 1 || (udfLen == 2 && udfName[1] == '.'))) {
437		needsCRC = 1;
438		newIndex = udfLen;
439		memcpy(newName, udfName, udfLen);
440	} else {
441		for (index = 0; index < udfLen; index++) {
442			curr = udfName[index];
443			if (curr == '/' || curr == 0) {
444				needsCRC = 1;
445				curr = ILLEGAL_CHAR_MARK;
446				while (index + 1 < udfLen &&
447						(udfName[index + 1] == '/' ||
448						 udfName[index + 1] == 0))
449					index++;
450			}
451			if (curr == EXT_MARK &&
452					(udfLen - index - 1) <= EXT_SIZE) {
453				if (udfLen == index + 1)
454					hasExt = 0;
455				else {
456					hasExt = 1;
457					extIndex = index;
458					newExtIndex = newIndex;
459				}
460			}
461			if (newIndex < newLen)
462				newName[newIndex++] = curr;
463			else
464				needsCRC = 1;
465		}
466	}
467	if (needsCRC) {
468		uint8_t ext[EXT_SIZE];
469		int localExtIndex = 0;
470
471		if (hasExt) {
472			int maxFilenameLen;
473			for (index = 0;
474			     index < EXT_SIZE && extIndex + index + 1 < udfLen;
475			     index++) {
476				curr = udfName[extIndex + index + 1];
477
478				if (curr == '/' || curr == 0) {
479					needsCRC = 1;
480					curr = ILLEGAL_CHAR_MARK;
481					while (extIndex + index + 2 < udfLen &&
482					      (index + 1 < EXT_SIZE &&
483						(udfName[extIndex + index + 2] == '/' ||
484						 udfName[extIndex + index + 2] == 0)))
485						index++;
486				}
487				ext[localExtIndex++] = curr;
488			}
489			maxFilenameLen = newLen - CRC_LEN - localExtIndex;
490			if (newIndex > maxFilenameLen)
491				newIndex = maxFilenameLen;
492			else
493				newIndex = newExtIndex;
494		} else if (newIndex > newLen - CRC_LEN)
495			newIndex = newLen - CRC_LEN;
496		newName[newIndex++] = CRC_MARK;
497		valueCRC = crc_itu_t(0, fidName, fidNameLen);
498		newName[newIndex++] = hex_asc_upper_hi(valueCRC >> 8);
499		newName[newIndex++] = hex_asc_upper_lo(valueCRC >> 8);
500		newName[newIndex++] = hex_asc_upper_hi(valueCRC);
501		newName[newIndex++] = hex_asc_upper_lo(valueCRC);
502
503		if (hasExt) {
504			newName[newIndex++] = EXT_MARK;
505			for (index = 0; index < localExtIndex; index++)
506				newName[newIndex++] = ext[index];
507		}
508	}
509
510	return newIndex;
511}
512