LXR linux/fs/nls/nls

   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
  14static struct nls_table *p_nls;
  15
  16static 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
  39static 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
  54static struct nls_table table = {
  55        .charset        = "koi8-ru",
  56        .uni2char       = uni2char,
  57        .char2uni       = char2uni,
  58};
  59
  60static 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
  73static void __exit exit_nls_koi8_ru(void)
  74{
  75        unregister_nls(&table);
  76        unload_nls(p_nls);
  77}
  78
  79module_init(init_nls_koi8_ru)
  80module_exit(exit_nls_koi8_ru)
  81
  82MODULE_LICENSE("Dual BSD/GPL");
  83