xref: /kernel/linux/linux-5.10/fs/nls/nls_base.c

/*
 * linux/fs/nls/nls_base.c
 *
 * Native language support--charsets and unicode translations.
 * By Gordon Chaffee 1996, 1997
 *
 * Unicode based case conversion 1999 by Wolfram Pienkoss
 *
 */

#include <linux/module.h>
#include <linux/string.h>
#include <linux/nls.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/kmod.h>
#include <linux/spinlock.h>
#include <asm/byteorder.h>

static struct nls_table default_table;
static struct nls_table *tables = &default_table;
static DEFINE_SPINLOCK(nls_lock);

/*
 * Sample implementation from Unicode home page.
 * http://www.stonehand.com/unicode/standard/fss-utf.html
 */
struct utf8_table {
	int     cmask;
	int     cval;
	int     shift;
	long    lmask;
	long    lval;
};

static const struct utf8_table utf8_table[] =
{
    {0x80,  0x00,   0*6,    0x7F,           0,         /* 1 byte sequence */},
    {0xE0,  0xC0,   1*6,    0x7FF,          0x80,      /* 2 byte sequence */},
    {0xF0,  0xE0,   2*6,    0xFFFF,         0x800,     /* 3 byte sequence */},
    {0xF8,  0xF0,   3*6,    0x1FFFFF,       0x10000,   /* 4 byte sequence */},
    {0xFC,  0xF8,   4*6,    0x3FFFFFF,      0x200000,  /* 5 byte sequence */},
    {0xFE,  0xFC,   5*6,    0x7FFFFFFF,     0x4000000, /* 6 byte sequence */},
    {0,						       /* end of table    */}
};

#define UNICODE_MAX	0x0010ffff
#define PLANE_SIZE	0x00010000

#define SURROGATE_MASK	0xfffff800
#define SURROGATE_PAIR	0x0000d800
#define SURROGATE_LOW	0x00000400
#define SURROGATE_BITS	0x000003ff

int utf8_to_utf32(const u8 *s, int inlen, unicode_t *pu)
{
	unsigned long l;
	int c0, c, nc;
	const struct utf8_table *t;

	nc = 0;
	c0 = *s;
	l = c0;
	for (t = utf8_table; t->cmask; t++) {
		nc++;
		if ((c0 & t->cmask) == t->cval) {
			l &= t->lmask;
			if (l < t->lval || l > UNICODE_MAX ||
					(l & SURROGATE_MASK) == SURROGATE_PAIR)
				return -1;
			*pu = (unicode_t) l;
			return nc;
		}
		if (inlen <= nc)
			return -1;
		s++;
		c = (*s ^ 0x80) & 0xFF;
		if (c & 0xC0)
			return -1;
		l = (l << 6) | c;
	}
	return -1;
}
EXPORT_SYMBOL(utf8_to_utf32);

int utf32_to_utf8(unicode_t u, u8 *s, int maxout)
{
	unsigned long l;
	int c, nc;
	const struct utf8_table *t;

	if (!s)
		return 0;

	l = u;
	if (l > UNICODE_MAX || (l & SURROGATE_MASK) == SURROGATE_PAIR)
		return -1;

	nc = 0;
	for (t = utf8_table; t->cmask && maxout; t++, maxout--) {
		nc++;
		if (l <= t->lmask) {
			c = t->shift;
			*s = (u8) (t->cval | (l >> c));
			while (c > 0) {
				c -= 6;
				s++;
				*s = (u8) (0x80 | ((l >> c) & 0x3F));
			}
			return nc;
		}
	}
	return -1;
}
EXPORT_SYMBOL(utf32_to_utf8);

static inline void put_utf16(wchar_t *s, unsigned c, enum utf16_endian endian)
{
	switch (endian) {
	default:
		*s = (wchar_t) c;
		break;
	case UTF16_LITTLE_ENDIAN:
		*s = __cpu_to_le16(c);
		break;
	case UTF16_BIG_ENDIAN:
		*s = __cpu_to_be16(c);
		break;
	}
}

int utf8s_to_utf16s(const u8 *s, int inlen, enum utf16_endian endian,
		wchar_t *pwcs, int maxout)
{
	u16 *op;
	int size;
	unicode_t u;

	op = pwcs;
	while (inlen > 0 && maxout > 0 && *s) {
		if (*s & 0x80) {
			size = utf8_to_utf32(s, inlen, &u);
			if (size < 0)
				return -EINVAL;
			s += size;
			inlen -= size;

			if (u >= PLANE_SIZE) {
				if (maxout < 2)
					break;
				u -= PLANE_SIZE;
				put_utf16(op++, SURROGATE_PAIR |
						((u >> 10) & SURROGATE_BITS),
						endian);
				put_utf16(op++, SURROGATE_PAIR |
						SURROGATE_LOW |
						(u & SURROGATE_BITS),
						endian);
				maxout -= 2;
			} else {
				put_utf16(op++, u, endian);
				maxout--;
			}
		} else {
			put_utf16(op++, *s++, endian);
			inlen--;
			maxout--;
		}
	}
	return op - pwcs;
}
EXPORT_SYMBOL(utf8s_to_utf16s);

static inline unsigned long get_utf16(unsigned c, enum utf16_endian endian)
{
	switch (endian) {
	default:
		return c;
	case UTF16_LITTLE_ENDIAN:
		return __le16_to_cpu(c);
	case UTF16_BIG_ENDIAN:
		return __be16_to_cpu(c);
	}
}

int utf16s_to_utf8s(const wchar_t *pwcs, int inlen, enum utf16_endian endian,
		u8 *s, int maxout)
{
	u8 *op;
	int size;
	unsigned long u, v;

	op = s;
	while (inlen > 0 && maxout > 0) {
		u = get_utf16(*pwcs, endian);
		if (!u)
			break;
		pwcs++;
		inlen--;
		if (u > 0x7f) {
			if ((u & SURROGATE_MASK) == SURROGATE_PAIR) {
				if (u & SURROGATE_LOW) {
					/* Ignore character and move on */
					continue;
				}
				if (inlen <= 0)
					break;
				v = get_utf16(*pwcs, endian);
				if ((v & SURROGATE_MASK) != SURROGATE_PAIR ||
						!(v & SURROGATE_LOW)) {
					/* Ignore character and move on */
					continue;
				}
				u = PLANE_SIZE + ((u & SURROGATE_BITS) << 10)
						+ (v & SURROGATE_BITS);
				pwcs++;
				inlen--;
			}
			size = utf32_to_utf8(u, op, maxout);
			if (size == -1) {
				/* Ignore character and move on */
			} else {
				op += size;
				maxout -= size;
			}
		} else {
			*op++ = (u8) u;
			maxout--;
		}
	}
	return op - s;
}
EXPORT_SYMBOL(utf16s_to_utf8s);

int __register_nls(struct nls_table *nls, struct module *owner)
{
	struct nls_table ** tmp = &tables;

	if (nls->next)
		return -EBUSY;

	nls->owner = owner;
	spin_lock(&nls_lock);
	while (*tmp) {
		if (nls == *tmp) {
			spin_unlock(&nls_lock);
			return -EBUSY;
		}
		tmp = &(*tmp)->next;
	}
	nls->next = tables;
	tables = nls;
	spin_unlock(&nls_lock);
	return 0;
}
EXPORT_SYMBOL(__register_nls);

int unregister_nls(struct nls_table * nls)
{
	struct nls_table ** tmp = &tables;

	spin_lock(&nls_lock);
	while (*tmp) {
		if (nls == *tmp) {
			*tmp = nls->next;
			spin_unlock(&nls_lock);
			return 0;
		}
		tmp = &(*tmp)->next;
	}
	spin_unlock(&nls_lock);
	return -EINVAL;
}

static struct nls_table *find_nls(const char *charset)
{
	struct nls_table *nls;
	spin_lock(&nls_lock);
	for (nls = tables; nls; nls = nls->next) {
		if (!strcmp(nls->charset, charset))
			break;
		if (nls->alias && !strcmp(nls->alias, charset))
			break;
	}
	if (nls && !try_module_get(nls->owner))
		nls = NULL;
	spin_unlock(&nls_lock);
	return nls;
}

struct nls_table *load_nls(const char *charset)
{
	return try_then_request_module(find_nls(charset), "nls_%s", charset);
}

void unload_nls(struct nls_table *nls)
{
	if (nls)
		module_put(nls->owner);
}

static const wchar_t charset2uni[256] = {
	/* 0x00*/
	0x0000, 0x0001, 0x0002, 0x0003,
	0x0004, 0x0005, 0x0006, 0x0007,
	0x0008, 0x0009, 0x000a, 0x000b,
	0x000c, 0x000d, 0x000e, 0x000f,
	/* 0x10*/
	0x0010, 0x0011, 0x0012, 0x0013,
	0x0014, 0x0015, 0x0016, 0x0017,
	0x0018, 0x0019, 0x001a, 0x001b,
	0x001c, 0x001d, 0x001e, 0x001f,
	/* 0x20*/
	0x0020, 0x0021, 0x0022, 0x0023,
	0x0024, 0x0025, 0x0026, 0x0027,
	0x0028, 0x0029, 0x002a, 0x002b,
	0x002c, 0x002d, 0x002e, 0x002f,
	/* 0x30*/
	0x0030, 0x0031, 0x0032, 0x0033,
	0x0034, 0x0035, 0x0036, 0x0037,
	0x0038, 0x0039, 0x003a, 0x003b,
	0x003c, 0x003d, 0x003e, 0x003f,
	/* 0x40*/
	0x0040, 0x0041, 0x0042, 0x0043,
	0x0044, 0x0045, 0x0046, 0x0047,
	0x0048, 0x0049, 0x004a, 0x004b,
	0x004c, 0x004d, 0x004e, 0x004f,
	/* 0x50*/
	0x0050, 0x0051, 0x0052, 0x0053,
	0x0054, 0x0055, 0x0056, 0x0057,
	0x0058, 0x0059, 0x005a, 0x005b,
	0x005c, 0x005d, 0x005e, 0x005f,
	/* 0x60*/
	0x0060, 0x0061, 0x0062, 0x0063,
	0x0064, 0x0065, 0x0066, 0x0067,
	0x0068, 0x0069, 0x006a, 0x006b,
	0x006c, 0x006d, 0x006e, 0x006f,
	/* 0x70*/
	0x0070, 0x0071, 0x0072, 0x0073,
	0x0074, 0x0075, 0x0076, 0x0077,
	0x0078, 0x0079, 0x007a, 0x007b,
	0x007c, 0x007d, 0x007e, 0x007f,
	/* 0x80*/
	0x0080, 0x0081, 0x0082, 0x0083,
	0x0084, 0x0085, 0x0086, 0x0087,
	0x0088, 0x0089, 0x008a, 0x008b,
	0x008c, 0x008d, 0x008e, 0x008f,
	/* 0x90*/
	0x0090, 0x0091, 0x0092, 0x0093,
	0x0094, 0x0095, 0x0096, 0x0097,
	0x0098, 0x0099, 0x009a, 0x009b,
	0x009c, 0x009d, 0x009e, 0x009f,
	/* 0xa0*/
	0x00a0, 0x00a1, 0x00a2, 0x00a3,
	0x00a4, 0x00a5, 0x00a6, 0x00a7,
	0x00a8, 0x00a9, 0x00aa, 0x00ab,
	0x00ac, 0x00ad, 0x00ae, 0x00af,
	/* 0xb0*/
	0x00b0, 0x00b1, 0x00b2, 0x00b3,
	0x00b4, 0x00b5, 0x00b6, 0x00b7,
	0x00b8, 0x00b9, 0x00ba, 0x00bb,
	0x00bc, 0x00bd, 0x00be, 0x00bf,
	/* 0xc0*/
	0x00c0, 0x00c1, 0x00c2, 0x00c3,
	0x00c4, 0x00c5, 0x00c6, 0x00c7,
	0x00c8, 0x00c9, 0x00ca, 0x00cb,
	0x00cc, 0x00cd, 0x00ce, 0x00cf,
	/* 0xd0*/
	0x00d0, 0x00d1, 0x00d2, 0x00d3,
	0x00d4, 0x00d5, 0x00d6, 0x00d7,
	0x00d8, 0x00d9, 0x00da, 0x00db,
	0x00dc, 0x00dd, 0x00de, 0x00df,
	/* 0xe0*/
	0x00e0, 0x00e1, 0x00e2, 0x00e3,
	0x00e4, 0x00e5, 0x00e6, 0x00e7,
	0x00e8, 0x00e9, 0x00ea, 0x00eb,
	0x00ec, 0x00ed, 0x00ee, 0x00ef,
	/* 0xf0*/
	0x00f0, 0x00f1, 0x00f2, 0x00f3,
	0x00f4, 0x00f5, 0x00f6, 0x00f7,
	0x00f8, 0x00f9, 0x00fa, 0x00fb,
	0x00fc, 0x00fd, 0x00fe, 0x00ff,
};

static const unsigned char page00[256] = {
	0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* 0x00-0x07 */
	0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, /* 0x08-0x0f */
	0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, /* 0x10-0x17 */
	0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, /* 0x18-0x1f */
	0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, /* 0x20-0x27 */
	0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, /* 0x28-0x2f */
	0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, /* 0x30-0x37 */
	0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, /* 0x38-0x3f */
	0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, /* 0x40-0x47 */
	0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, /* 0x48-0x4f */
	0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, /* 0x50-0x57 */
	0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, /* 0x58-0x5f */
	0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, /* 0x60-0x67 */
	0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, /* 0x68-0x6f */
	0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, /* 0x70-0x77 */
	0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, /* 0x78-0x7f */

	0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, /* 0x80-0x87 */
	0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, /* 0x88-0x8f */
	0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, /* 0x90-0x97 */
	0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, /* 0x98-0x9f */
	0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, /* 0xa0-0xa7 */
	0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, /* 0xa8-0xaf */
	0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, /* 0xb0-0xb7 */
	0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, /* 0xb8-0xbf */
	0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, /* 0xc0-0xc7 */
	0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, /* 0xc8-0xcf */
	0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, /* 0xd0-0xd7 */
	0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, /* 0xd8-0xdf */
	0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, /* 0xe0-0xe7 */
	0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, /* 0xe8-0xef */
	0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, /* 0xf0-0xf7 */
	0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, /* 0xf8-0xff */
};

static const unsigned char *const page_uni2charset[256] = {
	page00
};

static const unsigned char charset2lower[256] = {
	0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* 0x00-0x07 */
	0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, /* 0x08-0x0f */
	0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, /* 0x10-0x17 */
	0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, /* 0x18-0x1f */
	0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, /* 0x20-0x27 */
	0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, /* 0x28-0x2f */
	0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, /* 0x30-0x37 */
	0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, /* 0x38-0x3f */
	0x40, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, /* 0x40-0x47 */
	0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, /* 0x48-0x4f */
	0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, /* 0x50-0x57 */
	0x78, 0x79, 0x7a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, /* 0x58-0x5f */
	0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, /* 0x60-0x67 */
	0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, /* 0x68-0x6f */
	0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, /* 0x70-0x77 */
	0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, /* 0x78-0x7f */

	0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, /* 0x80-0x87 */
	0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, /* 0x88-0x8f */
	0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, /* 0x90-0x97 */
	0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, /* 0x98-0x9f */
	0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, /* 0xa0-0xa7 */
	0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, /* 0xa8-0xaf */
	0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, /* 0xb0-0xb7 */
	0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, /* 0xb8-0xbf */
	0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, /* 0xc0-0xc7 */
	0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, /* 0xc8-0xcf */
	0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, /* 0xd0-0xd7 */
	0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, /* 0xd8-0xdf */
	0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, /* 0xe0-0xe7 */
	0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, /* 0xe8-0xef */
	0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, /* 0xf0-0xf7 */
	0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, /* 0xf8-0xff */
};

static const unsigned char charset2upper[256] = {
	0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* 0x00-0x07 */
	0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, /* 0x08-0x0f */
	0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, /* 0x10-0x17 */
	0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, /* 0x18-0x1f */
	0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, /* 0x20-0x27 */
	0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, /* 0x28-0x2f */
	0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, /* 0x30-0x37 */
	0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, /* 0x38-0x3f */
	0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, /* 0x40-0x47 */
	0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, /* 0x48-0x4f */
	0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, /* 0x50-0x57 */
	0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, /* 0x58-0x5f */
	0x60, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, /* 0x60-0x67 */
	0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, /* 0x68-0x6f */
	0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, /* 0x70-0x77 */
	0x58, 0x59, 0x5a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, /* 0x78-0x7f */

	0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, /* 0x80-0x87 */
	0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, /* 0x88-0x8f */
	0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, /* 0x90-0x97 */
	0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, /* 0x98-0x9f */
	0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, /* 0xa0-0xa7 */
	0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, /* 0xa8-0xaf */
	0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, /* 0xb0-0xb7 */
	0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, /* 0xb8-0xbf */
	0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, /* 0xc0-0xc7 */
	0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, /* 0xc8-0xcf */
	0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, /* 0xd0-0xd7 */
	0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, /* 0xd8-0xdf */
	0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, /* 0xe0-0xe7 */
	0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, /* 0xe8-0xef */
	0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, /* 0xf0-0xf7 */
	0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, /* 0xf8-0xff */
};


static int uni2char(wchar_t uni, unsigned char *out, int boundlen)
{
	const unsigned char *uni2charset;
	unsigned char cl = uni & 0x00ff;
	unsigned char ch = (uni & 0xff00) >> 8;

	if (boundlen <= 0)
		return -ENAMETOOLONG;

	uni2charset = page_uni2charset[ch];
	if (uni2charset && uni2charset[cl])
		out[0] = uni2charset[cl];
	else
		return -EINVAL;
	return 1;
}

static int char2uni(const unsigned char *rawstring, int boundlen, wchar_t *uni)
{
	*uni = charset2uni[*rawstring];
	if (*uni == 0x0000)
		return -EINVAL;
	return 1;
}

static struct nls_table default_table = {
	.charset	= "default",
	.uni2char	= uni2char,
	.char2uni	= char2uni,
	.charset2lower	= charset2lower,
	.charset2upper	= charset2upper,
};

/* Returns a simple default translation table */
struct nls_table *load_nls_default(void)
{
	struct nls_table *default_nls;

	default_nls = load_nls(CONFIG_NLS_DEFAULT);
	if (default_nls != NULL)
		return default_nls;
	else
		return &default_table;
}

EXPORT_SYMBOL(unregister_nls);
EXPORT_SYMBOL(unload_nls);
EXPORT_SYMBOL(load_nls);
EXPORT_SYMBOL(load_nls_default);

MODULE_LICENSE("Dual BSD/GPL");