release/src-rt-6.x.4708/linux/linux-2.6.36/fs/nls/nls_utf8.c

   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 (boundlen <= 0)
  19                 return -ENAMETOOLONG;
  20
  21         n = utf32_to_utf8(uni, out, boundlen);
  22         if (n < 0) {
  23                 *out = '?';
  24                 return -EINVAL;
  25         }
  26         return n;
  27 }
  28
  29 static int char2uni(const unsigned char *rawstring, int boundlen, wchar_t *uni)
  30 {
  31         int n;
  32         unicode_t u;
  33
  34         n = utf8_to_utf32(rawstring, boundlen, &u);
  35         if (n < 0 || u > MAX_WCHAR_T) {
  36                 *uni = 0x003f;  /* ? */
  37                 return -EINVAL;
  38         }
  39         *uni = (wchar_t) u;
  40         return n;
  41 }
  42
  43 static struct nls_table table = {
  44         .charset        = "utf8",
  45         .uni2char       = uni2char,
  46         .char2uni       = char2uni,
  47         .charset2lower  = identity,     /* no conversion */
  48         .charset2upper  = identity,
  49         .owner          = THIS_MODULE,
  50 };
  51
  52 static int __init init_nls_utf8(void)
  53 {
  54         int i;
  55         for (i=0; i<256; i++)
  56                 identity[i] = i;
  57
  58         return register_nls(&table);
  59 }
  60
  61 static void __exit exit_nls_utf8(void)
  62 {
  63         unregister_nls(&table);
  64 }
  65
  66 module_init(init_nls_utf8)
  67 module_exit(exit_nls_utf8)
  68 MODULE_LICENSE("Dual BSD/GPL");