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: Alan Stern <stern@rowland.harvard.edu>
CC: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Stern 2011-11-17 16:42:19 -05:00 коммит произвёл Greg Kroah-Hartman
Родитель b7463c71fb
Коммит 0720a06a75
4 изменённых файлов: 48 добавлений и 21 удалений

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@ -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 */

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@ -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)

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@ -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;
if (u >= PLANE_SIZE) {
u -= PLANE_SIZE;
*op++ = (wchar_t) (SURROGATE_PAIR |
((u >> 10) & SURROGATE_BITS));
*op++ = (wchar_t) (SURROGATE_PAIR |
SURROGATE_LOW |
(u & SURROGATE_BITS));
} else {
*op++ = (wchar_t) u;
}
s += size;
len -= size;
if (u >= PLANE_SIZE) {
if (maxlen < 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);
maxlen -= 2;
} else {
put_utf16(op++, u, endian);
maxlen--;
}
} else {
*op++ = *s++;
put_utf16(op++, *s++, endian);
len--;
maxlen--;
}
}
return op - pwcs;

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@ -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);