[ 133/133] Convert properly UTF-8 to UTF-16

Greg Kroah-Hartman
2012-10-11T00:17:25Z

From: Frediano Ziglio <frediano.ziglio@citrix.com>

commit fd3ba42c76d3d4b776120c2b24c1791e7bb3deb1 upstream.

wchar_t is currently 16bit so converting a utf8 encoded characters not
in plane 0 (>= 0x10000) to wchar_t (that is calling char2uni) lead to a
-EINVAL return. This patch detect utf8 in cifs_strtoUTF16 and add special
code calling utf8s_to_utf16s.

Signed-off-by: Frediano Ziglio <frediano.ziglio@citrix.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/cifs/cifs_unicode.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)

--- a/fs/cifs/cifs_unicode.c
+++ b/fs/cifs/cifs_unicode.c
@@ -203,6 +203,27 @@ cifs_strtoUTF16(__le16 *to, const char *
int i;
wchar_t wchar_to; /* needed to quiet sparse */

+ /* special case for utf8 to handle no plane0 chars */
+ if (!strcmp(codepage->charset, "utf8")) {
+ /*
+ * convert utf8 -> utf16, we assume we have enough space
+ * as caller should have assumed conversion does not overflow
+ * in destination len is length in wchar_t units (16bits)
+ */
+ i = utf8s_to_utf16s(from, len, UTF16_LITTLE_ENDIAN,
+ (wchar_t *) to, len);
+
+ /* if success terminate and exit */
+ if (i >= 0)
+ goto success;
+ /*
+ * if fails fall back to UCS encoding as this
+ * function should not return negative values
+ * currently can fail only if source contains
+ * invalid encoded characters
+ */
+ }
+
for (i = 0; len && *from; i++, from += charlen, len -= charlen) {
charlen = codepage->char2uni(from, len, &wchar_to);
if (charlen < 1) {
@@ -215,6 +236,7 @@ cifs_strtoUTF16(__le16 *to, const char *
put_unaligned_le16(wchar_to, &to[i]);
}

+success:
put_unaligned_le16(0, &to[i]);
return i;
}