Commit 0720a06a authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
Browse files

NLS: improve UTF8 -> UTF16 string conversion routine 



The utf8s_to_utf16s conversion routine needs to be improved.  Unlike
its utf16s_to_utf8s sibling, it doesn't accept arguments specifying
the maximum length of the output buffer or the endianness of its
16-bit output.

This patch (as1501) adds the two missing arguments, and adjusts the
only two places in the kernel where the function is called.  A
follow-on patch will add a third caller that does utilize the new
capabilities.

The two conversion routines are still annoyingly inconsistent in the
way they handle invalid byte combinations.  But that's a subject for a
different patch.

Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
CC: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent b7463c71

drivers/hv/hv_kvp.c

+6 −4
Original line number Diff line number Diff line
@@ -212,11 +212,13 @@ kvp_respond_to_host(char *key, char *value, int error) 
	 * The windows host expects the key/value pair to be encoded

	 * in utf16.

	 */

	keylen = utf8s_to_utf16s(key_name, strlen(key_name),

				(wchar_t *)kvp_data->data.key);

	keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN,

				(wchar_t *) kvp_data->data.key,

				HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2);

	kvp_data->data.key_size = 2*(keylen + 1); /* utf16 encoding */

	valuelen = utf8s_to_utf16s(value, strlen(value),

				(wchar_t *)kvp_data->data.value);

	valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN,

				(wchar_t *) kvp_data->data.value,

				HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2);

	kvp_data->data.value_size = 2*(valuelen + 1); /* utf16 encoding */



	kvp_data->data.value_type = REG_SZ; /* all our values are strings */

fs/fat/namei_vfat.c

+2 −1
Original line number Diff line number Diff line
@@ -512,7 +512,8 @@ xlate_to_uni(const unsigned char *name, int len, unsigned char *outname, 
	int charlen;



	if (utf8) {

		*outlen = utf8s_to_utf16s(name, len, (wchar_t *)outname);

		*outlen = utf8s_to_utf16s(name, len, UTF16_HOST_ENDIAN,

				(wchar_t *) outname, FAT_LFN_LEN + 2);

		if (*outlen < 0)

			return *outlen;

		else if (*outlen > FAT_LFN_LEN)

fs/nls/nls_base.c

+33 −10
Original line number Diff line number Diff line
@@ -114,34 +114,57 @@ int utf32_to_utf8(unicode_t u, u8 *s, int maxlen) 
}

EXPORT_SYMBOL(utf32_to_utf8);



int utf8s_to_utf16s(const u8 *s, int len, wchar_t *pwcs)

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 len, enum utf16_endian endian,

		wchar_t *pwcs, int maxlen)

{

	u16 *op;

	int size;

	unicode_t u;



	op = pwcs;

	while (*s && len > 0) {

	while (len > 0 && maxlen > 0 && *s) {

		if (*s & 0x80) {

			size = utf8_to_utf32(s, len, &u);

			if (size < 0)

				return -EINVAL;

			s += size;

			len -= size;



			if (u >= PLANE_SIZE) {

				if (maxlen < 2)

					break;

				u -= PLANE_SIZE;

				*op++ = (wchar_t) (SURROGATE_PAIR |

						((u >> 10) & SURROGATE_BITS));

				*op++ = (wchar_t) (SURROGATE_PAIR |

				put_utf16(op++, SURROGATE_PAIR |

						((u >> 10) & SURROGATE_BITS),

						endian);

				put_utf16(op++, SURROGATE_PAIR |

						SURROGATE_LOW |

						(u & SURROGATE_BITS));

						(u & SURROGATE_BITS),

						endian);

				maxlen -= 2;

			} else {

				*op++ = (wchar_t) u;

				put_utf16(op++, u, endian);

				maxlen--;

			}

			s += size;

			len -= size;

		} else {

			*op++ = *s++;

			put_utf16(op++, *s++, endian);

			len--;

			maxlen--;

		}

	}

	return op - pwcs;

include/linux/nls.h

+3 −2
Original line number Diff line number Diff line
@@ -43,7 +43,7 @@ enum utf16_endian { 
	UTF16_BIG_ENDIAN

};



/* nls.c */

/* nls_base.c */

extern int register_nls(struct nls_table *);

extern int unregister_nls(struct nls_table *);

extern struct nls_table *load_nls(char *);
@@ -52,7 +52,8 @@ extern struct nls_table *load_nls_default(void); 


extern int utf8_to_utf32(const u8 *s, int len, unicode_t *pu);

extern int utf32_to_utf8(unicode_t u, u8 *s, int maxlen);

extern int utf8s_to_utf16s(const u8 *s, int len, wchar_t *pwcs);

extern int utf8s_to_utf16s(const u8 *s, int len,

		enum utf16_endian endian, wchar_t *pwcs, int maxlen);

extern int utf16s_to_utf8s(const wchar_t *pwcs, int len,

		enum utf16_endian endian, u8 *s, int maxlen);

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