cifs: fix potential buffer overrun when composing a new options string
[linux-2.6.git] / fs / nls / nls_koi8-ru.c
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         .owner          = THIS_MODULE,
59 };
60
61 static int __init init_nls_koi8_ru(void)
62 {
63         p_nls = load_nls("koi8-u");
64
65         if (p_nls) {
66                 table.charset2upper = p_nls->charset2upper;
67                 table.charset2lower = p_nls->charset2lower;
68                 return register_nls(&table);
69         }
70
71         return -EINVAL;
72 }
73
74 static void __exit exit_nls_koi8_ru(void)
75 {
76         unregister_nls(&table);
77         unload_nls(p_nls);
78 }
79
80 module_init(init_nls_koi8_ru)
81 module_exit(exit_nls_koi8_ru)
82
83 MODULE_LICENSE("Dual BSD/GPL");