fs/nls/nls_koi8-ru.c

0001 /*
0002  * linux/fs/nls/nls_koi8-ru.c
0003  *
0004  * Charset koi8-ru translation based on charset koi8-u.
0005  * The Unicode to charset table has only exact mappings.
0006  */
0007
0008 #include <linux/module.h>
0009 #include <linux/kernel.h>
0010 #include <linux/string.h>
0011 #include <linux/nls.h>
0012 #include <linux/errno.h>
0013
0014 static struct nls_table *p_nls;
0015
0016 static int uni2char(const wchar_t uni,
0017             unsigned char *out, int boundlen)
0018 {
0019     if (boundlen <= 0)
0020         return -ENAMETOOLONG;
0021
0022     if ((uni & 0xffaf) == 0x040e || (uni & 0xffce) == 0x254c) {
0023         /* koi8-ru and koi8-u differ only on two characters */
0024         if (uni == 0x040e)
0025             out[0] = 0xbe;
0026         else if (uni == 0x045e)
0027             out[0] = 0xae;
0028         else if (uni == 0x255d || uni == 0x256c)
0029             return 0;
0030         else
0031             return p_nls->uni2char(uni, out, boundlen);
0032         return 1;
0033     }
0034     else
0035         /* fast path */
0036         return p_nls->uni2char(uni, out, boundlen);
0037 }
0038
0039 static int char2uni(const unsigned char *rawstring, int boundlen,
0040             wchar_t *uni)
0041 {
0042     int n;
0043
0044     if ((*rawstring & 0xef) != 0xae) {
0045         /* koi8-ru and koi8-u differ only on two characters */
0046         *uni = (*rawstring & 0x10) ? 0x040e : 0x045e;
0047         return 1;
0048     }
0049
0050     n = p_nls->char2uni(rawstring, boundlen, uni);
0051     return n;
0052 }
0053
0054 static struct nls_table table = {
0055     .charset    = "koi8-ru",
0056     .uni2char   = uni2char,
0057     .char2uni   = char2uni,
0058 };
0059
0060 static int __init init_nls_koi8_ru(void)
0061 {
0062     p_nls = load_nls("koi8-u");
0063
0064     if (p_nls) {
0065         table.charset2upper = p_nls->charset2upper;
0066         table.charset2lower = p_nls->charset2lower;
0067         return register_nls(&table);
0068     }
0069
0070     return -EINVAL;
0071 }
0072
0073 static void __exit exit_nls_koi8_ru(void)
0074 {
0075     unregister_nls(&table);
0076     unload_nls(p_nls);
0077 }
0078
0079 module_init(init_nls_koi8_ru)
0080 module_exit(exit_nls_koi8_ru)
0081
0082 MODULE_LICENSE("Dual BSD/GPL");