/*
 * Module for handling utf8 just like any other charset.
 * By Urban Widmark 2000
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/nls.h>
#include <linux/errno.h>

static unsigned char identity[256];

static int uni2char(wchar_t uni, unsigned char *out, int boundlen)
{
        int n;

        if (boundlen <= 0)
                return -ENAMETOOLONG;

        n = utf32_to_utf8(uni, out, boundlen);
        if (n < 0) {
                *out = '?';
                return -EINVAL;
        }
        return n;
}

static int char2uni(const unsigned char *rawstring, int boundlen, wchar_t *uni)
{
        int n;
        unicode_t u;

        n = utf8_to_utf32(rawstring, boundlen, &u);
        if (n < 0 || u > MAX_WCHAR_T) {
                *uni = 0x003f;  /* ? */
                return -EINVAL;
        }
        *uni = (wchar_t) u;
        return n;
}

static struct nls_table table = {
        .charset        = "utf8",
        .uni2char       = uni2char,
        .char2uni       = char2uni,
        .charset2lower  = identity,     /* no conversion */
        .charset2upper  = identity,
};

static int __init init_nls_utf8(void)
{
        int i;
        for (i=0; i<256; i++)
                identity[i] = i;

        return register_nls(&table);
}

static void __exit exit_nls_utf8(void)
{
        unregister_nls(&table);
}

module_init(init_nls_utf8)
module_exit(exit_nls_utf8)
MODULE_DESCRIPTION("NLS UTF-8");
MODULE_LICENSE("Dual BSD/GPL");