aboutsummaryrefslogtreecommitdiff
path: root/fs/hfsplus/unicode.c
blob: 73342c925a4b6efb900885e849fa797fdc63782e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/hfsplus/unicode.c
 *
 * Copyright (C) 2001
 * Brad Boyer (flar@allandria.com)
 * (C) 2003 Ardis Technologies <roman@ardistech.com>
 *
 * Handler routines for unicode strings
 */

#include <linux/types.h>
#include <linux/nls.h>
#include "hfsplus_fs.h"
#include "hfsplus_raw.h"

/* Fold the case of a unicode char, given the 16 bit value */
/* Returns folded char, or 0 if ignorable */
static inline u16 case_fold(u16 c)
{
	u16 tmp;

	tmp = hfsplus_case_fold_table[c >> 8];
	if (tmp)
		tmp = hfsplus_case_fold_table[tmp + (c & 0xff)];
	else
		tmp = c;
	return tmp;
}

/* Compare unicode strings, return values like normal strcmp */
int hfsplus_strcasecmp(const struct hfsplus_unistr *s1,
		       const struct hfsplus_unistr *s2)
{
	u16 len1, len2, c1, c2;
	const hfsplus_unichr *p1, *p2;

	len1 = be16_to_cpu(s1->length);
	len2 = be16_to_cpu(s2->length);
	p1 = s1->unicode;
	p2 = s2->unicode;

	while (1) {
		c1 = c2 = 0;

		while (len1 && !c1) {
			c1 = case_fold(be16_to_cpu(*p1));
			p1++;
			len1--;
		}
		while (len2 && !c2) {
			c2 = case_fold(be16_to_cpu(*p2));
			p2++;
			len2--;
		}

		if (c1 != c2)
			return (c1 < c2) ? -1 : 1;
		if (!c1 && !c2)
			return 0;
	}
}

/* Compare names as a sequence of 16-bit unsigned integers */
int hfsplus_strcmp(const struct hfsplus_unistr *s1,
		   const struct hfsplus_unistr *s2)
{
	u16 len1, len2, c1, c2;
	const hfsplus_unichr *p1, *p2;
	int len;

	len1 = be16_to_cpu(s1->length);
	len2 = be16_to_cpu(s2->length);
	p1 = s1->unicode;
	p2 = s2->unicode;

	for (len = min(len1, len2); len > 0; len--) {
		c1 = be16_to_cpu(*p1);
		c2 = be16_to_cpu(*p2);
		if (c1 != c2)
			return c1 < c2 ? -1 : 1;
		p1++;
		p2++;
	}

	return len1 < len2 ? -1 :
	       len1 > len2 ? 1 : 0;
}


#define Hangul_SBase	0xac00
#define Hangul_LBase	0x1100
#define Hangul_VBase	0x1161
#define Hangul_TBase	0x11a7
#define Hangul_SCount	11172
#define Hangul_LCount	19
#define Hangul_VCount	21
#define Hangul_TCount	28
#define Hangul_NCount	(Hangul_VCount * Hangul_TCount)


static u16 *hfsplus_compose_lookup(u16 *p, u16 cc)
{
	int i, s, e;

	s = 1;
	e = p[1];
	if (!e || cc < p[s * 2] || cc > p[e * 2])
		return NULL;
	do {
		i = (s + e) / 2;
		if (cc > p[i * 2])
			s = i + 1;
		else if (cc < p[i * 2])
			e = i - 1;
		else
			return hfsplus_compose_table + p[i * 2 + 1];
	} while (s <= e);
	return NULL;
}

int hfsplus_uni2asc(struct super_block *sb,
		const struct hfsplus_unistr *ustr,
		char *astr, int *len_p)
{
	const hfsplus_unichr *ip;
	struct nls_table *nls = HFSPLUS_SB(sb)->nls;
	u8 *op;
	u16 cc, c0, c1;
	u16 *ce1, *ce2;
	int i, len, ustrlen, res, compose;

	op = astr;
	ip = ustr->unicode;
	ustrlen = be16_to_cpu(ustr->length);
	len = *len_p;
	ce1 = NULL;
	compose = !test_bit(HFSPLUS_SB_NODECOMPOSE, &HFSPLUS_SB(sb)->flags);

	while (ustrlen > 0) {
		c0 = be16_to_cpu(*ip++);
		ustrlen--;
		/* search for single decomposed char */
		if (likely(compose))
			ce1 = hfsplus_compose_lookup(hfsplus_compose_table, c0);
		if (ce1)
			cc = ce1[0];
		else
			cc = 0;
		if (cc) {
			/* start of a possibly decomposed Hangul char */
			if (cc != 0xffff)
				goto done;
			if (!ustrlen)
				goto same;
			c1 = be16_to_cpu(*ip) - Hangul_VBase;
			if (c1 < Hangul_VCount) {
				/* compose the Hangul char */
				cc = (c0 - Hangul_LBase) * Hangul_VCount;
				cc = (cc + c1) * Hangul_TCount;
				cc += Hangul_SBase;
				ip++;
				ustrlen--;
				if (!ustrlen)
					goto done;
				c1 = be16_to_cpu(*ip) - Hangul_TBase;
				if (c1 > 0 && c1 < Hangul_TCount) {
					cc += c1;
					ip++;
					ustrlen--;
				}
				goto done;
			}
		}
		while (1) {
			/* main loop for common case of not composed chars */
			if (!ustrlen)
				goto same;
			c1 = be16_to_cpu(*ip);
			if (likely(compose))
				ce1 = hfsplus_compose_lookup(
					hfsplus_compose_table, c1);
			if (ce1)
				break;
			switch (c0) {
			case 0:
				c0 = 0x2400;
				break;
			case '/':
				c0 = ':';
				break;
			}
			res = nls->uni2char(c0, op, len);
			if (res < 0) {
				if (res == -ENAMETOOLONG)
					goto out;
				*op = '?';
				res = 1;
			}
			op += res;
			len -= res;
			c0 = c1;
			ip++;
			ustrlen--;
		}
		ce2 = hfsplus_compose_lookup(ce1, c0);
		if (ce2) {
			i = 1;
			while (i < ustrlen) {
				ce1 = hfsplus_compose_lookup(ce2,
					be16_to_cpu(ip[i]));
				if (!ce1)
					break;
				i++;
				ce2 = ce1;
			}
			cc = ce2[0];
			if (cc) {
				ip += i;
				ustrlen -= i;
				goto done;
			}
		}
same:
		switch (c0) {
		case 0:
			cc = 0x2400;
			break;
		case '/':
			cc = ':';
			break;
		default:
			cc = c0;
		}
done:
		res = nls->uni2char(cc, op, len);
		if (res < 0) {
			if (res == -ENAMETOOLONG)
				goto out;
			*op = '?';
			res = 1;
		}
		op += res;
		len -= res;
	}
	res = 0;
out:
	*len_p = (char *)op - astr;
	return res;
}

/*
 * Convert one or more ASCII characters into a single unicode character.
 * Returns the number of ASCII characters corresponding to the unicode char.
 */
static inline int asc2unichar(struct super_block *sb, const char *astr, int len,
			      wchar_t *uc)
{
	int size = HFSPLUS_SB(sb)->nls->char2uni(astr, len, uc);
	if (size <= 0) {
		*uc = '?';
		size = 1;
	}
	switch (*uc) {
	case 0x2400:
		*uc = 0;
		break;
	case ':':
		*uc = '/';
		break;
	}
	return size;
}

/* Decomposes a non-Hangul unicode character. */
static u16 *hfsplus_decompose_nonhangul(wchar_t uc, int *size)
{
	int off;

	off = hfsplus_decompose_table[(uc >> 12) & 0xf];
	if (off == 0 || off == 0xffff)
		return NULL;

	off = hfsplus_decompose_table[off + ((uc >> 8) & 0xf)];
	if (!off)
		return NULL;

	off = hfsplus_decompose_table[off + ((uc >> 4) & 0xf)];
	if (!off)
		return NULL;

	off = hfsplus_decompose_table[off + (uc & 0xf)];
	*size = off & 3;
	if (*size == 0)
		return NULL;
	return hfsplus_decompose_table + (off / 4);
}

/*
 * Try to decompose a unicode character as Hangul. Return 0 if @uc is not
 * precomposed Hangul, otherwise return the length of the decomposition.
 *
 * This function was adapted from sample code from the Unicode Standard
 * Annex #15: Unicode Normalization Forms, version 3.2.0.
 *
 * Copyright (C) 1991-2018 Unicode, Inc.  All rights reserved.  Distributed
 * under the Terms of Use in http://www.unicode.org/copyright.html.
 */
static int hfsplus_try_decompose_hangul(wchar_t uc, u16 *result)
{
	int index;
	int l, v, t;

	index = uc - Hangul_SBase;
	if (index < 0 || index >= Hangul_SCount)
		return 0;

	l = Hangul_LBase + index / Hangul_NCount;
	v = Hangul_VBase + (index % Hangul_NCount) / Hangul_TCount;
	t = Hangul_TBase + index % Hangul_TCount;

	result[0] = l;
	result[1] = v;
	if (t != Hangul_TBase) {
		result[2] = t;
		return 3;
	}
	return 2;
}

/* Decomposes a single unicode character. */
static u16 *decompose_unichar(wchar_t uc, int *size, u16 *hangul_buffer)
{
	u16 *result;

	/* Hangul is handled separately */
	result = hangul_buffer;
	*size = hfsplus_try_decompose_hangul(uc, result);
	if (*size == 0)
		result = hfsplus_decompose_nonhangul(uc, size);
	return result;
}

int hfsplus_asc2uni(struct super_block *sb,
		    struct hfsplus_unistr *ustr, int max_unistr_len,
		    const char *astr, int len)
{
	int size, dsize, decompose;
	u16 *dstr, outlen = 0;
	wchar_t c;
	u16 dhangul[3];

	decompose = !test_bit(HFSPLUS_SB_NODECOMPOSE, &HFSPLUS_SB(sb)->flags);
	while (outlen < max_unistr_len && len > 0) {
		size = asc2unichar(sb, astr, len, &c);

		if (decompose)
			dstr = decompose_unichar(c, &dsize, dhangul);
		else
			dstr = NULL;
		if (dstr) {
			if (outlen + dsize > max_unistr_len)
				break;
			do {
				ustr->unicode[outlen++] = cpu_to_be16(*dstr++);
			} while (--dsize > 0);
		} else
			ustr->unicode[outlen++] = cpu_to_be16(c);

		astr += size;
		len -= size;
	}
	ustr->length = cpu_to_be16(outlen);
	if (len > 0)
		return -ENAMETOOLONG;
	return 0;
}

/*
 * Hash a string to an integer as appropriate for the HFS+ filesystem.
 * Composed unicode characters are decomposed and case-folding is performed
 * if the appropriate bits are (un)set on the superblock.
 */
int hfsplus_hash_dentry(const struct dentry *dentry, struct qstr *str)
{
	struct super_block *sb = dentry->d_sb;
	const char *astr;
	const u16 *dstr;
	int casefold, decompose, size, len;
	unsigned long hash;
	wchar_t c;
	u16 c2;
	u16 dhangul[3];

	casefold = test_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags);
	decompose = !test_bit(HFSPLUS_SB_NODECOMPOSE, &HFSPLUS_SB(sb)->flags);
	hash = init_name_hash(dentry);
	astr = str->name;
	len = str->len;
	while (len > 0) {
		int dsize;
		size = asc2unichar(sb, astr, len, &c);
		astr += size;
		len -= size;

		if (decompose)
			dstr = decompose_unichar(c, &dsize, dhangul);
		else
			dstr = NULL;
		if (dstr) {
			do {
				c2 = *dstr++;
				if (casefold)
					c2 = case_fold(c2);
				if (!casefold || c2)
					hash = partial_name_hash(c2, hash);
			} while (--dsize > 0);
		} else {
			c2 = c;
			if (casefold)
				c2 = case_fold(c2);
			if (!casefold || c2)
				hash = partial_name_hash(c2, hash);
		}
	}
	str->hash = end_name_hash(hash);

	return 0;
}

/*
 * Compare strings with HFS+ filename ordering.
 * Composed unicode characters are decomposed and case-folding is performed
 * if the appropriate bits are (un)set on the superblock.
 */
int hfsplus_compare_dentry(const struct dentry *dentry,
		unsigned int len, const char *str, const struct qstr *name)
{
	struct super_block *sb = dentry->d_sb;
	int casefold, decompose, size;
	int dsize1, dsize2, len1, len2;
	const u16 *dstr1, *dstr2;
	const char *astr1, *astr2;
	u16 c1, c2;
	wchar_t c;
	u16 dhangul_1[3], dhangul_2[3];

	casefold = test_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags);
	decompose = !test_bit(HFSPLUS_SB_NODECOMPOSE, &HFSPLUS_SB(sb)->flags);
	astr1 = str;
	len1 = len;
	astr2 = name->name;
	len2 = name->len;
	dsize1 = dsize2 = 0;
	dstr1 = dstr2 = NULL;

	while (len1 > 0 && len2 > 0) {
		if (!dsize1) {
			size = asc2unichar(sb, astr1, len1, &c);
			astr1 += size;
			len1 -= size;

			if (decompose)
				dstr1 = decompose_unichar(c, &dsize1,
							  dhangul_1);
			if (!decompose || !dstr1) {
				c1 = c;
				dstr1 = &c1;
				dsize1 = 1;
			}
		}

		if (!dsize2) {
			size = asc2unichar(sb, astr2, len2, &c);
			astr2 += size;
			len2 -= size;

			if (decompose)
				dstr2 = decompose_unichar(c, &dsize2,
							  dhangul_2);
			if (!decompose || !dstr2) {
				c2 = c;
				dstr2 = &c2;
				dsize2 = 1;
			}
		}

		c1 = *dstr1;
		c2 = *dstr2;
		if (casefold) {
			c1 = case_fold(c1);
			if (!c1) {
				dstr1++;
				dsize1--;
				continue;
			}
			c2 = case_fold(c2);
			if (!c2) {
				dstr2++;
				dsize2--;
				continue;
			}
		}
		if (c1 < c2)
			return -1;
		else if (c1 > c2)
			return 1;

		dstr1++;
		dsize1--;
		dstr2++;
		dsize2--;
	}

	if (len1 < len2)
		return -1;
	if (len1 > len2)
		return 1;
	return 0;
}