Line data Source code
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11 : * wchar_t values is now outdated.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 1 : typedef u16 wchar_t;
19 : #define MAX_WCHAR_T 0xffff
20 :
21 : /* Arbitrary Unicode character */
22 1 : typedef u32 unicode_t;
23 1 :
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.c */
47 : extern int register_nls(struct nls_table *);
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 :
53 : extern int utf8_to_utf32(const u8 *s, int len, unicode_t *pu);
54 : extern int utf32_to_utf8(unicode_t u, u8 *s, int maxlen);
55 : extern int utf8s_to_utf16s(const u8 *s, int len, wchar_t *pwcs);
56 : extern int utf16s_to_utf8s(const wchar_t *pwcs, int len,
57 : enum utf16_endian endian, u8 *s, int maxlen);
58 :
59 : static inline unsigned char nls_tolower(struct nls_table *t, unsigned char c)
60 : {
61 : unsigned char nc = t->charset2lower[c];
62 :
63 : return nc ? nc : c;
64 : }
65 :
66 : static inline unsigned char nls_toupper(struct nls_table *t, unsigned char c)
67 : {
68 : unsigned char nc = t->charset2upper[c];
69 :
70 : return nc ? nc : c;
71 : }
72 :
73 : static inline int nls_strnicmp(struct nls_table *t, const unsigned char *s1,
74 : const unsigned char *s2, int len)
75 : {
76 : while (len--) {
77 : if (nls_tolower(t, *s1++) != nls_tolower(t, *s2++))
78 : return 1;
79 : }
80 :
81 : return 0;
82 : }
83 :
84 : /*
85 : * nls_nullsize - return length of null character for codepage
86 : * @codepage - codepage for which to return length of NULL terminator
87 : *
88 : * Since we can't guarantee that the null terminator will be a particular
89 : * length, we have to check against the codepage. If there's a problem
90 : * determining it, assume a single-byte NULL terminator.
91 : */
92 : static inline int
93 : nls_nullsize(const struct nls_table *codepage)
94 : {
95 : int charlen;
96 : char tmp[NLS_MAX_CHARSET_SIZE];
97 :
98 : charlen = codepage->uni2char(0, tmp, NLS_MAX_CHARSET_SIZE);
99 :
100 : return charlen > 0 ? charlen : 1;
101 : }
102 :
103 : #define MODULE_ALIAS_NLS(name) MODULE_ALIAS("nls_" __stringify(name))
104 :
105 : #endif /* _LINUX_NLS_H */
106 :
|