cifs: fix unaligned accesses in cifsConvertToUCS

Move cifsConvertToUCS to cifs_unicode.c where all of the other unicode
related functions live. Have it store mapped characters in 'temp' and
then use put_unaligned_le16 to copy it to the target buffer. Also fix
the comments to match kernel coding style.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 76 insertions, 0 deletions

diff --git a/fs/cifs/cifs_unicode.c b/fs/cifs/cifs_unicode.c
index 5f6e71857be..fc0fd4fde30 100644
--- a/fs/cifs/cifs_unicode.c
+++ b/fs/cifs/cifs_unicode.c
@@ -257,3 +257,79 @@ cifs_strndup_from_ucs(const char *src, const int maxlen, const bool is_unicode,
 	return dst;
 }
 
+/*
+ * Convert 16 bit Unicode pathname to wire format from string in current code
+ * page. Conversion may involve remapping up the six characters that are
+ * only legal in POSIX-like OS (if they are present in the string). Path
+ * names are little endian 16 bit Unicode on the wire
+ */
+int
+cifsConvertToUCS(__le16 *target, const char *source, int maxlen,
+		 const struct nls_table *cp, int mapChars)
+{
+	int i, j, charlen;
+	int len_remaining = maxlen;
+	char src_char;
+	__u16 temp;
+
+	if (!mapChars)
+		return cifs_strtoUCS(target, source, PATH_MAX, cp);
+
+	for (i = 0, j = 0; i < maxlen; j++) {
+		src_char = source[i];
+		switch (src_char) {
+		case 0:
+			put_unaligned_le16(0, &target[j]);
+			goto ctoUCS_out;
+		case ':':
+			temp = UNI_COLON;
+			break;
+		case '*':
+			temp = UNI_ASTERIK;
+			break;
+		case '?':
+			temp = UNI_QUESTION;
+			break;
+		case '<':
+			temp = UNI_LESSTHAN;
+			break;
+		case '>':
+			temp = UNI_GRTRTHAN;
+			break;
+		case '|':
+			temp = UNI_PIPE;
+			break;
+		/*
+		 * FIXME: We can not handle remapping backslash (UNI_SLASH)
+		 * until all the calls to build_path_from_dentry are modified,
+		 * as they use backslash as separator.
+		 */
+		default:
+			charlen = cp->char2uni(source+i, len_remaining,
+						&temp);
+			/*
+			 * if no match, use question mark, which at least in
+			 * some cases serves as wild card
+			 */
+			if (charlen < 1) {
+				temp = 0x003f;
+				charlen = 1;
+			}
+			len_remaining -= charlen;
+			/*
+			 * character may take more than one byte in the source
+			 * string, but will take exactly two bytes in the
+			 * target string
+			 */
+			i += charlen;
+			continue;
+		}
+		put_unaligned_le16(temp, &target[j]);
+		i++; /* move to next char in source string */
+		len_remaining--;
+	}
+
+ctoUCS_out:
+	return i;
+}
+