1 #ifndef _LINUX_NLS_H 2 #define _LINUX_NLS_H 3 4 #include <linux/init.h> 5 6 /* Unicode has changed over the years. Unicode code points no longer 7 * fit into 16 bits; as of Unicode 5 valid code points range from 0 8 * to 0x10ffff (17 planes, where each plane holds 65536 code points). 9 * 10 * The original decision to represent Unicode characters as 16-bit 11 * wchar_t values is now outdated. But plane 0 still includes the 12 * most commonly used characters, so we will retain it. The newer 13 * 32-bit unicode_t type can be used when it is necessary to 14 * represent the full Unicode character set. 15 */ 16 17 /* Plane-0 Unicode character */ 18 typedef u16 wchar_t; 19 #define MAX_WCHAR_T 0xffff 20 21 /* Arbitrary Unicode character */ 22 typedef u32 unicode_t; 23 24 struct nls_table { 25 const char *charset; 26 const char *alias; 27 int (*uni2char) (wchar_t uni, unsigned char *out, int boundlen); 28 int (*char2uni) (const unsigned char *rawstring, int boundlen, 29 wchar_t *uni); 30 const unsigned char *charset2lower; 31 const unsigned char *charset2upper; 32 struct module *owner; 33 struct nls_table *next; 34 }; 35 36 /* this value hold the maximum octet of charset */ 37 #define NLS_MAX_CHARSET_SIZE 6 /* for UTF-8 */ 38 39 /* Byte order for UTF-16 strings */ 40 enum utf16_endian { 41 UTF16_HOST_ENDIAN, 42 UTF16_LITTLE_ENDIAN, 43 UTF16_BIG_ENDIAN 44 }; 45 46 /* nls_base.c */ 47 extern int __register_nls(struct nls_table *, struct module *); 48 extern int unregister_nls(struct nls_table *); 49 extern struct nls_table *load_nls(char *); 50 extern void unload_nls(struct nls_table *); 51 extern struct nls_table *load_nls_default(void); 52 #define register_nls(nls) __register_nls((nls), THIS_MODULE) 53 54 extern int utf8_to_utf32(const u8 *s, int len, unicode_t *pu); 55 extern int utf32_to_utf8(unicode_t u, u8 *s, int maxlen); 56 extern int utf8s_to_utf16s(const u8 *s, int len, 57 enum utf16_endian endian, wchar_t *pwcs, int maxlen); 58 extern int utf16s_to_utf8s(const wchar_t *pwcs, int len, 59 enum utf16_endian endian, u8 *s, int maxlen); 60 61 static inline unsigned char nls_tolower(struct nls_table *t, unsigned char c) 62 { 63 unsigned char nc = t->charset2lower[c]; 64 65 return nc ? nc : c; 66 } 67 68 static inline unsigned char nls_toupper(struct nls_table *t, unsigned char c) 69 { 70 unsigned char nc = t->charset2upper[c]; 71 72 return nc ? nc : c; 73 } 74 75 static inline int nls_strnicmp(struct nls_table *t, const unsigned char *s1, 76 const unsigned char *s2, int len) 77 { 78 while (len--) { 79 if (nls_tolower(t, *s1++) != nls_tolower(t, *s2++)) 80 return 1; 81 } 82 83 return 0; 84 } 85 86 /* 87 * nls_nullsize - return length of null character for codepage 88 * @codepage - codepage for which to return length of NULL terminator 89 * 90 * Since we can't guarantee that the null terminator will be a particular 91 * length, we have to check against the codepage. If there's a problem 92 * determining it, assume a single-byte NULL terminator. 93 */ 94 static inline int 95 nls_nullsize(const struct nls_table *codepage) 96 { 97 int charlen; 98 char tmp[NLS_MAX_CHARSET_SIZE]; 99 100 charlen = codepage->uni2char(0, tmp, NLS_MAX_CHARSET_SIZE); 101 102 return charlen > 0 ? charlen : 1; 103 } 104 105 #define MODULE_ALIAS_NLS(name) MODULE_ALIAS("nls_" __stringify(name)) 106 107 #endif /* _LINUX_NLS_H */ 108 109