1 files changed, 83 insertions, 0 deletions
diff --git a/fs/nls/nls_koi8-ru.c b/fs/nls/nls_koi8-ru.c
new file mode 100644
index 000000000000..5db83efe27c6
--- /dev/null
+++ b/fs/nls/nls_koi8-ru.c
@@ -0,0 +1,83 @@
+/*
+ * linux/fs/nls_koi8-ru.c
+ *
+ * Charset koi8-ru translation based on charset koi8-u.
+ * The Unicode to charset table has only exact mappings.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/nls.h>
+#include <linux/errno.h>
+
+static struct nls_table *p_nls;
+
+static int uni2char(const wchar_t uni,
+		    unsigned char *out, int boundlen)
+{
+	if (boundlen <= 0)
+		return -ENAMETOOLONG;
+
+	if ((uni & 0xffaf) == 0x040e || (uni & 0xffce) == 0x254c) {
+		/* koi8-ru and koi8-u differ only on two characters */
+		if (uni == 0x040e)
+			out[0] = 0xbe;
+		else if (uni == 0x045e)
+			out[0] = 0xae;
+		else if (uni == 0x255d || uni == 0x256c)
+			return 0;
+		else
+			return p_nls->uni2char(uni, out, boundlen);
+		return 1;
+	}
+	else
+		/* fast path */
+		return p_nls->uni2char(uni, out, boundlen);
+}
+
+static int char2uni(const unsigned char *rawstring, int boundlen,
+		    wchar_t *uni)
+{
+	int n;
+
+	if ((*rawstring & 0xef) != 0xae) {
+		/* koi8-ru and koi8-u differ only on two characters */
+		*uni = (*rawstring & 0x10) ? 0x040e : 0x045e;
+		return 1;
+	}
+
+	n = p_nls->char2uni(rawstring, boundlen, uni);
+	return n;
+}
+
+static struct nls_table table = {
+	.charset	= "koi8-ru",
+	.uni2char	= uni2char,
+	.char2uni	= char2uni,
+	.owner		= THIS_MODULE,
+};
+
+static int __init init_nls_koi8_ru(void)
+{
+	p_nls = load_nls("koi8-u");
+
+	if (p_nls) {
+		table.charset2upper = p_nls->charset2upper;
+		table.charset2lower = p_nls->charset2lower;
+		return register_nls(&table);
+	}
+
+	return -EINVAL;
+}
+
+static void __exit exit_nls_koi8_ru(void)
+{
+	unregister_nls(&table);
+	unload_nls(p_nls);
+}
+
+module_init(init_nls_koi8_ru)
+module_exit(exit_nls_koi8_ru)
+
+MODULE_LICENSE("Dual BSD/GPL");