1 /*
2  * Module for handling utf8 just like any other charset.
3  * By Urban Widmark 2000
4  */
5 
6 #include <linux/module.h>
7 #include <linux/kernel.h>
8 #include <linux/string.h>
9 #include <linux/nls.h>
10 #include <linux/errno.h>
11 
12 static unsigned char identity[256];
13 
14 static int uni2char(wchar_t uni, unsigned char *out, int boundlen)
15 {
16     int n;
17 
18     if ( (n = utf8_wctomb(out, uni, boundlen)) == -1) {
19         *out = '?';
20         return -EINVAL;
21     }
22     return n;
23 }
24 
25 static int char2uni(const unsigned char *rawstring, int boundlen, wchar_t *uni)
26 {
27     int n;
28 
29     if ( (n = utf8_mbtowc(uni, rawstring, boundlen)) == -1) {
30         *uni = 0x003f;	/* ? */
31         n = -EINVAL;
32     }
33     return n;
34 }
35 
36 static struct nls_table table = {
37     /* .charset */ "utf8",
38     /* .alias */   0,
39     /* .uni2char */ uni2char,
40     /* .char2uni */ char2uni,
41     /* .charset2lower */ identity,	/* no conversion */
42     /* .charset2upper */ identity,
43     /* .owner */ THIS_MODULE,
44 };
45 
46 static int __init init_nls_utf8(void)
47 {
48     int i;
49     for (i=0; i<256; i++)
50         identity[i] = (unsigned char) i;
51 
52     return register_nls(&table);
53 }
54 
55 static void __exit exit_nls_utf8(void)
56 {
57     unregister_nls(&table);
58 }
59 
60 module_init(init_nls_utf8)
61 module_exit(exit_nls_utf8)
62 MODULE_LICENSE("Dual BSD/GPL");
63