diff options
Diffstat (limited to 'include/linux/nls.h')
| -rw-r--r-- | include/linux/nls.h | 54 |
1 files changed, 48 insertions, 6 deletions
diff --git a/include/linux/nls.h b/include/linux/nls.h index 6a882208301..d47beef08df 100644 --- a/include/linux/nls.h +++ b/include/linux/nls.h @@ -3,8 +3,23 @@ #include <linux/init.h> -/* unicode character */ -typedef __u16 wchar_t; +/* Unicode has changed over the years. Unicode code points no longer + * fit into 16 bits; as of Unicode 5 valid code points range from 0 + * to 0x10ffff (17 planes, where each plane holds 65536 code points). + * + * The original decision to represent Unicode characters as 16-bit + * wchar_t values is now outdated. But plane 0 still includes the + * most commonly used characters, so we will retain it. The newer + * 32-bit unicode_t type can be used when it is necessary to + * represent the full Unicode character set. + */ + +/* Plane-0 Unicode character */ +typedef u16 wchar_t; +#define MAX_WCHAR_T 0xffff + +/* Arbitrary Unicode character */ +typedef u32 unicode_t; struct nls_table { const char *charset; @@ -21,6 +36,13 @@ struct nls_table { /* this value hold the maximum octet of charset */ #define NLS_MAX_CHARSET_SIZE 6 /* for UTF-8 */ +/* Byte order for UTF-16 strings */ +enum utf16_endian { + UTF16_HOST_ENDIAN, + UTF16_LITTLE_ENDIAN, + UTF16_BIG_ENDIAN +}; + /* nls.c */ extern int register_nls(struct nls_table *); extern int unregister_nls(struct nls_table *); @@ -28,10 +50,11 @@ extern struct nls_table *load_nls(char *); extern void unload_nls(struct nls_table *); extern struct nls_table *load_nls_default(void); -extern int utf8_mbtowc(wchar_t *, const __u8 *, int); -extern int utf8_mbstowcs(wchar_t *, const __u8 *, int); -extern int utf8_wctomb(__u8 *, wchar_t, int); -extern int utf8_wcstombs(__u8 *, const wchar_t *, int); +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 utf16s_to_utf8s(const wchar_t *pwcs, int len, + enum utf16_endian endian, u8 *s, int maxlen); static inline unsigned char nls_tolower(struct nls_table *t, unsigned char c) { @@ -58,6 +81,25 @@ static inline int nls_strnicmp(struct nls_table *t, const unsigned char *s1, return 0; } +/* + * nls_nullsize - return length of null character for codepage + * @codepage - codepage for which to return length of NULL terminator + * + * Since we can't guarantee that the null terminator will be a particular + * length, we have to check against the codepage. If there's a problem + * determining it, assume a single-byte NULL terminator. + */ +static inline int +nls_nullsize(const struct nls_table *codepage) +{ + int charlen; + char tmp[NLS_MAX_CHARSET_SIZE]; + + charlen = codepage->uni2char(0, tmp, NLS_MAX_CHARSET_SIZE); + + return charlen > 0 ? charlen : 1; +} + #define MODULE_ALIAS_NLS(name) MODULE_ALIAS("nls_" __stringify(name)) #endif /* _LINUX_NLS_H */ |