aboutsummaryrefslogtreecommitdiff
path: root/sys/contrib/openzfs/module/unicode/uconv.c
blob: fe84979d08b2d259584f9224c88bdfe713831b26 (plain) (blame)
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
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */



/*
 * Unicode encoding conversion functions among UTF-8, UTF-16, and UTF-32.
 * (PSARC/2005/446, PSARC/2007/038, PSARC/2007/517)
 * Man pages: uconv_u16tou32(9F), uconv_u16tou8(9F), uconv_u32tou16(9F),
 * uconv_u32tou8(9F), uconv_u8tou16(9F), and uconv_u8tou32(9F). See also
 * the section 3C man pages.
 * Interface stability: Committed
 */

#include <sys/types.h>
#ifdef	_KERNEL
#include <sys/param.h>
#include <sys/sysmacros.h>
#include <sys/debug.h>
#include <sys/kmem.h>
#include <sys/sunddi.h>
#else
#include <sys/u8_textprep.h>
#endif	/* _KERNEL */
#include <sys/byteorder.h>
#include <sys/errno.h>


/*
 * The max and min values of high and low surrogate pairs of UTF-16,
 * UTF-16 bit shift value, bit mask, and starting value outside of BMP.
 */
#define	UCONV_U16_HI_MIN	(0xd800U)
#define	UCONV_U16_HI_MAX	(0xdbffU)
#define	UCONV_U16_LO_MIN	(0xdc00U)
#define	UCONV_U16_LO_MAX	(0xdfffU)
#define	UCONV_U16_BIT_SHIFT	(0x0400U)
#define	UCONV_U16_BIT_MASK	(0x0fffffU)
#define	UCONV_U16_START		(0x010000U)

/* The maximum value of Unicode coding space and ASCII coding space. */
#define	UCONV_UNICODE_MAX	(0x10ffffU)
#define	UCONV_ASCII_MAX		(0x7fU)

/* The mask values for input and output endians. */
#define	UCONV_IN_ENDIAN_MASKS	(UCONV_IN_BIG_ENDIAN | UCONV_IN_LITTLE_ENDIAN)
#define	UCONV_OUT_ENDIAN_MASKS	(UCONV_OUT_BIG_ENDIAN | UCONV_OUT_LITTLE_ENDIAN)

/* Native and reversed endian macros. */
#ifdef	_ZFS_BIG_ENDIAN
#define	UCONV_IN_NAT_ENDIAN	UCONV_IN_BIG_ENDIAN
#define	UCONV_IN_REV_ENDIAN	UCONV_IN_LITTLE_ENDIAN
#define	UCONV_OUT_NAT_ENDIAN	UCONV_OUT_BIG_ENDIAN
#define	UCONV_OUT_REV_ENDIAN	UCONV_OUT_LITTLE_ENDIAN
#else
#define	UCONV_IN_NAT_ENDIAN	UCONV_IN_LITTLE_ENDIAN
#define	UCONV_IN_REV_ENDIAN	UCONV_IN_BIG_ENDIAN
#define	UCONV_OUT_NAT_ENDIAN	UCONV_OUT_LITTLE_ENDIAN
#define	UCONV_OUT_REV_ENDIAN	UCONV_OUT_BIG_ENDIAN
#endif	/* _BIG_ENDIAN */

/* The Byte Order Mark (BOM) character in normal and reversed byte orderings. */
#define	UCONV_BOM_NORMAL	(0xfeffU)
#define	UCONV_BOM_SWAPPED	(0xfffeU)
#define	UCONV_BOM_SWAPPED_32	(0xfffe0000U)

/* UTF-32 boundaries based on UTF-8 character byte lengths. */
#define	UCONV_U8_ONE_BYTE	(0x7fU)
#define	UCONV_U8_TWO_BYTES	(0x7ffU)
#define	UCONV_U8_THREE_BYTES	(0xffffU)
#define	UCONV_U8_FOUR_BYTES	(0x10ffffU)

/* The common minimum and maximum values at the UTF-8 character bytes. */
#define	UCONV_U8_BYTE_MIN	(0x80U)
#define	UCONV_U8_BYTE_MAX	(0xbfU)

/*
 * The following "6" and "0x3f" came from "10xx xxxx" bit representation of
 * UTF-8 character bytes.
 */
#define	UCONV_U8_BIT_SHIFT	6
#define	UCONV_U8_BIT_MASK	0x3f

/*
 * The following vector shows remaining bytes in a UTF-8 character.
 * Index will be the first byte of the character.
 */
static const uchar_t remaining_bytes_tbl[0x100] = {
	0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
	0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
	0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
	0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
	0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
	0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
	0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
	0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
	0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
	0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
	0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
	0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,

/*	C0  C1  C2  C3  C4  C5  C6  C7  C8  C9  CA  CB  CC  CD  CE  CF */
	0,  0,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,

/*	D0  D1  D2  D3  D4  D5  D6  D7  D8  D9  DA  DB  DC  DD  DE  DF */
	1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,

/*	E0  E1  E2  E3  E4  E5  E6  E7  E8  E9  EA  EB  EC  ED  EE  EF */
	2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,

/*	F0  F1  F2  F3  F4  F5  F6  F7  F8  F9  FA  FB  FC  FD  FE  FF */
	3,  3,  3,  3,  3,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0
};

/*
 * The following is a vector of bit-masks to get used bits in
 * the first byte of a UTF-8 character.  Index is remaining bytes at above of
 * the character.
 */
#ifdef	_KERNEL
const uchar_t u8_masks_tbl[6] = { 0x00, 0x1f, 0x0f, 0x07, 0x03, 0x01 };
#else
static const uchar_t u8_masks_tbl[6] = { 0x00, 0x1f, 0x0f, 0x07, 0x03, 0x01 };
#endif	/* _KERNEL */

/*
 * The following two vectors are to provide valid minimum and
 * maximum values for the 2'nd byte of a multibyte UTF-8 character for
 * better illegal sequence checking. The index value must be the value of
 * the first byte of the UTF-8 character.
 */
static const uchar_t valid_min_2nd_byte[0x100] = {
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,

/*	C0    C1    C2    C3    C4    C5    C6    C7 */
	0,    0,    0x80, 0x80, 0x80, 0x80, 0x80, 0x80,

/*	C8    C9    CA    CB    CC    CD    CE    CF */
	0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,

/*	D0    D1    D2    D3    D4    D5    D6    D7 */
	0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,

/*	D8    D9    DA    DB    DC    DD    DE    DF */
	0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,

/*	E0    E1    E2    E3    E4    E5    E6    E7 */
	0xa0, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,

/*	E8    E9    EA    EB    EC    ED    EE    EF */
	0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,

/*	F0    F1    F2    F3    F4    F5    F6    F7 */
	0x90, 0x80, 0x80, 0x80, 0x80, 0,    0,    0,

	0,    0,    0,    0,    0,    0,    0,    0
};

static const uchar_t valid_max_2nd_byte[0x100] = {
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,
	0,    0,    0,    0,    0,    0,    0,    0,

/*	C0    C1    C2    C3    C4    C5    C6    C7 */
	0,    0,    0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf,

/*	C8    C9    CA    CB    CC    CD    CE    CF */
	0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf,

/*	D0    D1    D2    D3    D4    D5    D6    D7 */
	0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf,

/*	D8    D9    DA    DB    DC    DD    DE    DF */
	0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf,

/*	E0    E1    E2    E3    E4    E5    E6    E7 */
	0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0xbf,

/*	E8    E9    EA    EB    EC    ED    EE    EF */
	0xbf, 0xbf, 0xbf, 0xbf, 0xbf, 0x9f, 0xbf, 0xbf,

/*	F0    F1    F2    F3    F4    F5    F6    F7 */
	0xbf, 0xbf, 0xbf, 0xbf, 0x8f, 0,    0,    0,

	0,    0,    0,    0,    0,    0,    0,    0
};


static int
check_endian(int flag, int *in, int *out)
{
	*in = flag & UCONV_IN_ENDIAN_MASKS;

	/* You cannot have both. */
	if (*in == UCONV_IN_ENDIAN_MASKS)
		return (EBADF);

	if (*in == 0)
		*in = UCONV_IN_NAT_ENDIAN;

	*out = flag & UCONV_OUT_ENDIAN_MASKS;

	/* You cannot have both. */
	if (*out == UCONV_OUT_ENDIAN_MASKS)
		return (EBADF);

	if (*out == 0)
		*out = UCONV_OUT_NAT_ENDIAN;

	return (0);
}

static boolean_t
check_bom16(const uint16_t *u16s, size_t u16l, int *in)
{
	if (u16l > 0) {
		if (*u16s == UCONV_BOM_NORMAL) {
			*in = UCONV_IN_NAT_ENDIAN;
			return (B_TRUE);
		}
		if (*u16s == UCONV_BOM_SWAPPED) {
			*in = UCONV_IN_REV_ENDIAN;
			return (B_TRUE);
		}
	}

	return (B_FALSE);
}

static boolean_t
check_bom32(const uint32_t *u32s, size_t u32l, int *in)
{
	if (u32l > 0) {
		if (*u32s == UCONV_BOM_NORMAL) {
			*in = UCONV_IN_NAT_ENDIAN;
			return (B_TRUE);
		}
		if (*u32s == UCONV_BOM_SWAPPED_32) {
			*in = UCONV_IN_REV_ENDIAN;
			return (B_TRUE);
		}
	}

	return (B_FALSE);
}

int
uconv_u16tou32(const uint16_t *u16s, size_t *utf16len,
    uint32_t *u32s, size_t *utf32len, int flag)
{
	int inendian;
	int outendian;
	size_t u16l;
	size_t u32l;
	uint32_t hi;
	uint32_t lo;
	boolean_t do_not_ignore_null;

	/*
	 * Do preliminary validity checks on parameters and collect info on
	 * endians.
	 */
	if (u16s == NULL || utf16len == NULL)
		return (EILSEQ);

	if (u32s == NULL || utf32len == NULL)
		return (E2BIG);

	if (check_endian(flag, &inendian, &outendian) != 0)
		return (EBADF);

	/*
	 * Initialize input and output parameter buffer indices and
	 * temporary variables.
	 */
	u16l = u32l = 0;
	hi = 0;
	do_not_ignore_null = ((flag & UCONV_IGNORE_NULL) == 0);

	/*
	 * Check on the BOM at the beginning of the input buffer if required
	 * and if there is indeed one, process it.
	 */
	if ((flag & UCONV_IN_ACCEPT_BOM) &&
	    check_bom16(u16s, *utf16len, &inendian))
		u16l++;

	/*
	 * Reset inendian and outendian so that after this point, those can be
	 * used as condition values.
	 */
	inendian &= UCONV_IN_NAT_ENDIAN;
	outendian &= UCONV_OUT_NAT_ENDIAN;

	/*
	 * If there is something in the input buffer and if necessary and
	 * requested, save the BOM at the output buffer.
	 */
	if (*utf16len > 0 && *utf32len > 0 && (flag & UCONV_OUT_EMIT_BOM))
		u32s[u32l++] = (outendian) ? UCONV_BOM_NORMAL :
		    UCONV_BOM_SWAPPED_32;

	/*
	 * Do conversion; if encounter a surrogate pair, assemble high and
	 * low pair values to form a UTF-32 character. If a half of a pair
	 * exists alone, then, either it is an illegal (EILSEQ) or
	 * invalid (EINVAL) value.
	 */
	for (; u16l < *utf16len; u16l++) {
		if (u16s[u16l] == 0 && do_not_ignore_null)
			break;

		lo = (uint32_t)((inendian) ? u16s[u16l] : BSWAP_16(u16s[u16l]));

		if (lo >= UCONV_U16_HI_MIN && lo <= UCONV_U16_HI_MAX) {
			if (hi)
				return (EILSEQ);
			hi = lo;
			continue;
		} else if (lo >= UCONV_U16_LO_MIN && lo <= UCONV_U16_LO_MAX) {
			if (! hi)
				return (EILSEQ);
			lo = (((hi - UCONV_U16_HI_MIN) * UCONV_U16_BIT_SHIFT +
			    lo - UCONV_U16_LO_MIN) & UCONV_U16_BIT_MASK)
			    + UCONV_U16_START;
			hi = 0;
		} else if (hi) {
			return (EILSEQ);
		}

		if (u32l >= *utf32len)
			return (E2BIG);

		u32s[u32l++] = (outendian) ? lo : BSWAP_32(lo);
	}

	/*
	 * If high half didn't see low half, then, it's most likely the input
	 * parameter is incomplete.
	 */
	if (hi)
		return (EINVAL);

	/*
	 * Save the number of consumed and saved characters. They do not
	 * include terminating NULL character (U+0000) at the end of
	 * the input buffer (even when UCONV_IGNORE_NULL isn't specified and
	 * the input buffer length is big enough to include the terminating
	 * NULL character).
	 */
	*utf16len = u16l;
	*utf32len = u32l;

	return (0);
}

int
uconv_u16tou8(const uint16_t *u16s, size_t *utf16len,
    uchar_t *u8s, size_t *utf8len, int flag)
{
	int inendian;
	int outendian;
	size_t u16l;
	size_t u8l;
	uint32_t hi;
	uint32_t lo;
	boolean_t do_not_ignore_null;

	if (u16s == NULL || utf16len == NULL)
		return (EILSEQ);

	if (u8s == NULL || utf8len == NULL)
		return (E2BIG);

	if (check_endian(flag, &inendian, &outendian) != 0)
		return (EBADF);

	u16l = u8l = 0;
	hi = 0;
	do_not_ignore_null = ((flag & UCONV_IGNORE_NULL) == 0);

	if ((flag & UCONV_IN_ACCEPT_BOM) &&
	    check_bom16(u16s, *utf16len, &inendian))
		u16l++;

	inendian &= UCONV_IN_NAT_ENDIAN;

	for (; u16l < *utf16len; u16l++) {
		if (u16s[u16l] == 0 && do_not_ignore_null)
			break;

		lo = (uint32_t)((inendian) ? u16s[u16l] : BSWAP_16(u16s[u16l]));

		if (lo >= UCONV_U16_HI_MIN && lo <= UCONV_U16_HI_MAX) {
			if (hi)
				return (EILSEQ);
			hi = lo;
			continue;
		} else if (lo >= UCONV_U16_LO_MIN && lo <= UCONV_U16_LO_MAX) {
			if (! hi)
				return (EILSEQ);
			lo = (((hi - UCONV_U16_HI_MIN) * UCONV_U16_BIT_SHIFT +
			    lo - UCONV_U16_LO_MIN) & UCONV_U16_BIT_MASK)
			    + UCONV_U16_START;
			hi = 0;
		} else if (hi) {
			return (EILSEQ);
		}

		/*
		 * Now we convert a UTF-32 character into a UTF-8 character.
		 * Unicode coding space is between U+0000 and U+10FFFF;
		 * anything bigger is an illegal character.
		 */
		if (lo <= UCONV_U8_ONE_BYTE) {
			if (u8l >= *utf8len)
				return (E2BIG);
			u8s[u8l++] = (uchar_t)lo;
		} else if (lo <= UCONV_U8_TWO_BYTES) {
			if ((u8l + 1) >= *utf8len)
				return (E2BIG);
			u8s[u8l++] = (uchar_t)(0xc0 | ((lo & 0x07c0) >> 6));
			u8s[u8l++] = (uchar_t)(0x80 |  (lo & 0x003f));
		} else if (lo <= UCONV_U8_THREE_BYTES) {
			if ((u8l + 2) >= *utf8len)
				return (E2BIG);
			u8s[u8l++] = (uchar_t)(0xe0 | ((lo & 0x0f000) >> 12));
			u8s[u8l++] = (uchar_t)(0x80 | ((lo & 0x00fc0) >> 6));
			u8s[u8l++] = (uchar_t)(0x80 |  (lo & 0x0003f));
		} else if (lo <= UCONV_U8_FOUR_BYTES) {
			if ((u8l + 3) >= *utf8len)
				return (E2BIG);
			u8s[u8l++] = (uchar_t)(0xf0 | ((lo & 0x01c0000) >> 18));
			u8s[u8l++] = (uchar_t)(0x80 | ((lo & 0x003f000) >> 12));
			u8s[u8l++] = (uchar_t)(0x80 | ((lo & 0x0000fc0) >> 6));
			u8s[u8l++] = (uchar_t)(0x80 |  (lo & 0x000003f));
		} else {
			return (EILSEQ);
		}
	}

	if (hi)
		return (EINVAL);

	*utf16len = u16l;
	*utf8len = u8l;

	return (0);
}

int
uconv_u32tou16(const uint32_t *u32s, size_t *utf32len,
    uint16_t *u16s, size_t *utf16len, int flag)
{
	int inendian;
	int outendian;
	size_t u16l;
	size_t u32l;
	uint32_t hi;
	uint32_t lo;
	boolean_t do_not_ignore_null;

	if (u32s == NULL || utf32len == NULL)
		return (EILSEQ);

	if (u16s == NULL || utf16len == NULL)
		return (E2BIG);

	if (check_endian(flag, &inendian, &outendian) != 0)
		return (EBADF);

	u16l = u32l = 0;
	do_not_ignore_null = ((flag & UCONV_IGNORE_NULL) == 0);

	if ((flag & UCONV_IN_ACCEPT_BOM) &&
	    check_bom32(u32s, *utf32len, &inendian))
		u32l++;

	inendian &= UCONV_IN_NAT_ENDIAN;
	outendian &= UCONV_OUT_NAT_ENDIAN;

	if (*utf32len > 0 && *utf16len > 0 && (flag & UCONV_OUT_EMIT_BOM))
		u16s[u16l++] = (outendian) ? UCONV_BOM_NORMAL :
		    UCONV_BOM_SWAPPED;

	for (; u32l < *utf32len; u32l++) {
		if (u32s[u32l] == 0 && do_not_ignore_null)
			break;

		hi = (inendian) ? u32s[u32l] : BSWAP_32(u32s[u32l]);

		/*
		 * Anything bigger than the Unicode coding space, i.e.,
		 * Unicode scalar value bigger than U+10FFFF, is an illegal
		 * character.
		 */
		if (hi > UCONV_UNICODE_MAX)
			return (EILSEQ);

		/*
		 * Anything bigger than U+FFFF must be converted into
		 * a surrogate pair in UTF-16.
		 */
		if (hi >= UCONV_U16_START) {
			lo = ((hi - UCONV_U16_START) % UCONV_U16_BIT_SHIFT) +
			    UCONV_U16_LO_MIN;
			hi = ((hi - UCONV_U16_START) / UCONV_U16_BIT_SHIFT) +
			    UCONV_U16_HI_MIN;

			if ((u16l + 1) >= *utf16len)
				return (E2BIG);

			if (outendian) {
				u16s[u16l++] = (uint16_t)hi;
				u16s[u16l++] = (uint16_t)lo;
			} else {
				u16s[u16l++] = BSWAP_16(((uint16_t)hi));
				u16s[u16l++] = BSWAP_16(((uint16_t)lo));
			}
		} else {
			if (u16l >= *utf16len)
				return (E2BIG);
			u16s[u16l++] = (outendian) ? (uint16_t)hi :
			    BSWAP_16(((uint16_t)hi));
		}
	}

	*utf16len = u16l;
	*utf32len = u32l;

	return (0);
}

int
uconv_u32tou8(const uint32_t *u32s, size_t *utf32len,
    uchar_t *u8s, size_t *utf8len, int flag)
{
	int inendian;
	int outendian;
	size_t u32l;
	size_t u8l;
	uint32_t lo;
	boolean_t do_not_ignore_null;

	if (u32s == NULL || utf32len == NULL)
		return (EILSEQ);

	if (u8s == NULL || utf8len == NULL)
		return (E2BIG);

	if (check_endian(flag, &inendian, &outendian) != 0)
		return (EBADF);

	u32l = u8l = 0;
	do_not_ignore_null = ((flag & UCONV_IGNORE_NULL) == 0);

	if ((flag & UCONV_IN_ACCEPT_BOM) &&
	    check_bom32(u32s, *utf32len, &inendian))
		u32l++;

	inendian &= UCONV_IN_NAT_ENDIAN;

	for (; u32l < *utf32len; u32l++) {
		if (u32s[u32l] == 0 && do_not_ignore_null)
			break;

		lo = (inendian) ? u32s[u32l] : BSWAP_32(u32s[u32l]);

		if (lo <= UCONV_U8_ONE_BYTE) {
			if (u8l >= *utf8len)
				return (E2BIG);
			u8s[u8l++] = (uchar_t)lo;
		} else if (lo <= UCONV_U8_TWO_BYTES) {
			if ((u8l + 1) >= *utf8len)
				return (E2BIG);
			u8s[u8l++] = (uchar_t)(0xc0 | ((lo & 0x07c0) >> 6));
			u8s[u8l++] = (uchar_t)(0x80 |  (lo & 0x003f));
		} else if (lo <= UCONV_U8_THREE_BYTES) {
			if ((u8l + 2) >= *utf8len)
				return (E2BIG);
			u8s[u8l++] = (uchar_t)(0xe0 | ((lo & 0x0f000) >> 12));
			u8s[u8l++] = (uchar_t)(0x80 | ((lo & 0x00fc0) >> 6));
			u8s[u8l++] = (uchar_t)(0x80 |  (lo & 0x0003f));
		} else if (lo <= UCONV_U8_FOUR_BYTES) {
			if ((u8l + 3) >= *utf8len)
				return (E2BIG);
			u8s[u8l++] = (uchar_t)(0xf0 | ((lo & 0x01c0000) >> 18));
			u8s[u8l++] = (uchar_t)(0x80 | ((lo & 0x003f000) >> 12));
			u8s[u8l++] = (uchar_t)(0x80 | ((lo & 0x0000fc0) >> 6));
			u8s[u8l++] = (uchar_t)(0x80 |  (lo & 0x000003f));
		} else {
			return (EILSEQ);
		}
	}

	*utf32len = u32l;
	*utf8len = u8l;

	return (0);
}

int
uconv_u8tou16(const uchar_t *u8s, size_t *utf8len,
    uint16_t *u16s, size_t *utf16len, int flag)
{
	int inendian;
	int outendian;
	size_t u16l;
	size_t u8l;
	uint32_t hi;
	uint32_t lo;
	int remaining_bytes;
	int first_b;
	boolean_t do_not_ignore_null;

	if (u8s == NULL || utf8len == NULL)
		return (EILSEQ);

	if (u16s == NULL || utf16len == NULL)
		return (E2BIG);

	if (check_endian(flag, &inendian, &outendian) != 0)
		return (EBADF);

	u16l = u8l = 0;
	do_not_ignore_null = ((flag & UCONV_IGNORE_NULL) == 0);

	outendian &= UCONV_OUT_NAT_ENDIAN;

	if (*utf8len > 0 && *utf16len > 0 && (flag & UCONV_OUT_EMIT_BOM))
		u16s[u16l++] = (outendian) ? UCONV_BOM_NORMAL :
		    UCONV_BOM_SWAPPED;

	for (; u8l < *utf8len; ) {
		if (u8s[u8l] == 0 && do_not_ignore_null)
			break;

		/*
		 * Collect a UTF-8 character and convert it to a UTF-32
		 * character. In doing so, we screen out illegally formed
		 * UTF-8 characters and treat such as illegal characters.
		 * The algorithm at below also screens out anything bigger
		 * than the U+10FFFF.
		 *
		 * See Unicode 3.1 UTF-8 Corrigendum and Unicode 3.2 for
		 * more details on the illegal values of UTF-8 character
		 * bytes.
		 */
		hi = (uint32_t)u8s[u8l++];

		if (hi > UCONV_ASCII_MAX) {
			if ((remaining_bytes = remaining_bytes_tbl[hi]) == 0)
				return (EILSEQ);

			first_b = hi;
			hi = hi & u8_masks_tbl[remaining_bytes];

			for (; remaining_bytes > 0; remaining_bytes--) {
				/*
				 * If we have no more bytes, the current
				 * UTF-8 character is incomplete.
				 */
				if (u8l >= *utf8len)
					return (EINVAL);

				lo = (uint32_t)u8s[u8l++];

				if (first_b) {
					if (lo < valid_min_2nd_byte[first_b] ||
					    lo > valid_max_2nd_byte[first_b])
						return (EILSEQ);
					first_b = 0;
				} else if (lo < UCONV_U8_BYTE_MIN ||
				    lo > UCONV_U8_BYTE_MAX) {
					return (EILSEQ);
				}
				hi = (hi << UCONV_U8_BIT_SHIFT) |
				    (lo & UCONV_U8_BIT_MASK);
			}
		}

		if (hi >= UCONV_U16_START) {
			lo = ((hi - UCONV_U16_START) % UCONV_U16_BIT_SHIFT) +
			    UCONV_U16_LO_MIN;
			hi = ((hi - UCONV_U16_START) / UCONV_U16_BIT_SHIFT) +
			    UCONV_U16_HI_MIN;

			if ((u16l + 1) >= *utf16len)
				return (E2BIG);

			if (outendian) {
				u16s[u16l++] = (uint16_t)hi;
				u16s[u16l++] = (uint16_t)lo;
			} else {
				u16s[u16l++] = BSWAP_16(((uint16_t)hi));
				u16s[u16l++] = BSWAP_16(((uint16_t)lo));
			}
		} else {
			if (u16l >= *utf16len)
				return (E2BIG);

			u16s[u16l++] = (outendian) ? (uint16_t)hi :
			    BSWAP_16(((uint16_t)hi));
		}
	}

	*utf16len = u16l;
	*utf8len = u8l;

	return (0);
}

int
uconv_u8tou32(const uchar_t *u8s, size_t *utf8len,
    uint32_t *u32s, size_t *utf32len, int flag)
{
	int inendian;
	int outendian;
	size_t u32l;
	size_t u8l;
	uint32_t hi;
	uint32_t c;
	int remaining_bytes;
	int first_b;
	boolean_t do_not_ignore_null;

	if (u8s == NULL || utf8len == NULL)
		return (EILSEQ);

	if (u32s == NULL || utf32len == NULL)
		return (E2BIG);

	if (check_endian(flag, &inendian, &outendian) != 0)
		return (EBADF);

	u32l = u8l = 0;
	do_not_ignore_null = ((flag & UCONV_IGNORE_NULL) == 0);

	outendian &= UCONV_OUT_NAT_ENDIAN;

	if (*utf8len > 0 && *utf32len > 0 && (flag & UCONV_OUT_EMIT_BOM))
		u32s[u32l++] = (outendian) ? UCONV_BOM_NORMAL :
		    UCONV_BOM_SWAPPED_32;

	for (; u8l < *utf8len; ) {
		if (u8s[u8l] == 0 && do_not_ignore_null)
			break;

		hi = (uint32_t)u8s[u8l++];

		if (hi > UCONV_ASCII_MAX) {
			if ((remaining_bytes = remaining_bytes_tbl[hi]) == 0)
				return (EILSEQ);

			first_b = hi;
			hi = hi & u8_masks_tbl[remaining_bytes];

			for (; remaining_bytes > 0; remaining_bytes--) {
				if (u8l >= *utf8len)
					return (EINVAL);

				c = (uint32_t)u8s[u8l++];

				if (first_b) {
					if (c < valid_min_2nd_byte[first_b] ||
					    c > valid_max_2nd_byte[first_b])
						return (EILSEQ);
					first_b = 0;
				} else if (c < UCONV_U8_BYTE_MIN ||
				    c > UCONV_U8_BYTE_MAX) {
					return (EILSEQ);
				}
				hi = (hi << UCONV_U8_BIT_SHIFT) |
				    (c & UCONV_U8_BIT_MASK);
			}
		}

		if (u32l >= *utf32len)
			return (E2BIG);

		u32s[u32l++] = (outendian) ? hi : BSWAP_32(hi);
	}

	*utf32len = u32l;
	*utf8len = u8l;

	return (0);
}

#if defined(_KERNEL)
EXPORT_SYMBOL(uconv_u16tou32);
EXPORT_SYMBOL(uconv_u16tou8);
EXPORT_SYMBOL(uconv_u32tou16);
EXPORT_SYMBOL(uconv_u32tou8);
EXPORT_SYMBOL(uconv_u8tou16);
EXPORT_SYMBOL(uconv_u8tou32);
#endif