fs/nls/nls_utf8.c

0001 /*
0002  * Module for handling utf8 just like any other charset.
0003  * By Urban Widmark 2000
0004  */
0005
0006 #include <linux/module.h>
0007 #include <linux/kernel.h>
0008 #include <linux/string.h>
0009 #include <linux/nls.h>
0010 #include <linux/errno.h>
0011
0012 static unsigned char identity[256];
0013
0014 static int uni2char(wchar_t uni, unsigned char *out, int boundlen)
0015 {
0016     int n;
0017
0018     if (boundlen <= 0)
0019         return -ENAMETOOLONG;
0020
0021     n = utf32_to_utf8(uni, out, boundlen);
0022     if (n < 0) {
0023         *out = '?';
0024         return -EINVAL;
0025     }
0026     return n;
0027 }
0028
0029 static int char2uni(const unsigned char *rawstring, int boundlen, wchar_t *uni)
0030 {
0031     int n;
0032     unicode_t u;
0033
0034     n = utf8_to_utf32(rawstring, boundlen, &u);
0035     if (n < 0 || u > MAX_WCHAR_T) {
0036         *uni = 0x003f;  /* ? */
0037         return -EINVAL;
0038     }
0039     *uni = (wchar_t) u;
0040     return n;
0041 }
0042
0043 static struct nls_table table = {
0044     .charset    = "utf8",
0045     .uni2char   = uni2char,
0046     .char2uni   = char2uni,
0047     .charset2lower  = identity, /* no conversion */
0048     .charset2upper  = identity,
0049 };
0050
0051 static int __init init_nls_utf8(void)
0052 {
0053     int i;
0054     for (i=0; i<256; i++)
0055         identity[i] = i;
0056
0057         return register_nls(&table);
0058 }
0059
0060 static void __exit exit_nls_utf8(void)
0061 {
0062         unregister_nls(&table);
0063 }
0064
0065 module_init(init_nls_utf8)
0066 module_exit(exit_nls_utf8)
0067 MODULE_LICENSE("Dual BSD/GPL");