1 /*
2 * linux/fs/nls/nls_koi8-ru.c
3 *
4 * Charset koi8-ru translation based on charset koi8-u.
5 * The Unicode to charset table has only exact mappings.
6 */
7
8 #include <linux/module.h>
9 #include <linux/kernel.h>
10 #include <linux/string.h>
11 #include <linux/nls.h>
12 #include <linux/errno.h>
13
14 static struct nls_table *p_nls;
15
16 static int uni2char(const wchar_t uni,
17 unsigned char *out, int boundlen)
18 {
19 if (boundlen <= 0)
20 return -ENAMETOOLONG;
21
22 if ((uni & 0xffaf) == 0x040e || (uni & 0xffce) == 0x254c) {
23 /* koi8-ru and koi8-u differ only on two characters */
24 if (uni == 0x040e)
25 out[0] = 0xbe;
26 else if (uni == 0x045e)
27 out[0] = 0xae;
28 else if (uni == 0x255d || uni == 0x256c)
29 return 0;
30 else
31 return p_nls->uni2char(uni, out, boundlen);
32 return 1;
33 }
34 else
35 /* fast path */
36 return p_nls->uni2char(uni, out, boundlen);
37 }
38
39 static int char2uni(const unsigned char *rawstring, int boundlen,
40 wchar_t *uni)
41 {
42 int n;
43
44 if ((*rawstring & 0xef) != 0xae) {
45 /* koi8-ru and koi8-u differ only on two characters */
46 *uni = (*rawstring & 0x10) ? 0x040e : 0x045e;
47 return 1;
48 }
49
50 n = p_nls->char2uni(rawstring, boundlen, uni);
51 return n;
52 }
53
54 static struct nls_table table = {
55 .charset = "koi8-ru",
56 .uni2char = uni2char,
57 .char2uni = char2uni,
58 };
59
60 static int __init init_nls_koi8_ru(void)
61 {
62 p_nls = load_nls("koi8-u");
63
64 if (p_nls) {
65 table.charset2upper = p_nls->charset2upper;
66 table.charset2lower = p_nls->charset2lower;
67 return register_nls(&table);
68 }
69
70 return -EINVAL;
71 }
72
73 static void __exit exit_nls_koi8_ru(void)
74 {
75 unregister_nls(&table);
76 unload_nls(p_nls);
77 }
78
79 module_init(init_nls_koi8_ru)
80 module_exit(exit_nls_koi8_ru)
81
82 MODULE_DESCRIPTION("NLS KOI8-RU (Belarusian)");
83 MODULE_LICENSE("Dual BSD/GPL");
84
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