ext2fs: add method to validate casefolded strings

This is exported to be used by fsck.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Arnaud Ferraris <arnaud.ferraris@collabora.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

3 files changed, 32 insertions, 0 deletions

diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index b1752ac7e..68f6b0292 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -1633,6 +1633,8 @@ extern errcode_t ext2fs_new_dir_inline_data(ext2_filsys fs, ext2_ino_t dir_ino,
 
 /* nls_utf8.c */
 extern const struct ext2fs_nls_table *ext2fs_load_nls_table(int encoding);
+extern int ext2fs_check_encoded_name(const struct ext2fs_nls_table *table,
+				     char *s, size_t len, char **pos);
 
 /* mkdir.c */
 extern errcode_t ext2fs_mkdir(ext2_filsys fs, ext2_ino_t parent, ext2_ino_t inum,
diff --git a/lib/ext2fs/ext2fsP.h b/lib/ext2fs/ext2fsP.h
index ad8b7d52d..30564ded1 100644
--- a/lib/ext2fs/ext2fsP.h
+++ b/lib/ext2fs/ext2fsP.h
@@ -104,6 +104,8 @@ struct ext2fs_nls_ops {
 	int (*casefold)(const struct ext2fs_nls_table *charset,
 			const unsigned char *str, size_t len,
 			unsigned char *dest, size_t dlen);
+	int (*validate)(const struct ext2fs_nls_table *table,
+			char *s, size_t len, char **pos);
 };
 
 /* Function prototypes */
diff --git a/lib/ext2fs/nls_utf8.c b/lib/ext2fs/nls_utf8.c
index e4c4e7a30..7d2cf4214 100644
--- a/lib/ext2fs/nls_utf8.c
+++ b/lib/ext2fs/nls_utf8.c
@@ -920,8 +920,30 @@ invalid_seq:
 	return -EINVAL;
 }
 
+static int utf8_validate(const struct ext2fs_nls_table *table,
+			 char *s, size_t len, char **pos)
+{
+	const struct utf8data *data = utf8nfdicf(table->version);
+	utf8leaf_t	*leaf;
+	unsigned char	hangul[UTF8HANGULLEAF];
+
+	if (!data)
+		return -1;
+	while (len && *s) {
+		leaf = utf8nlookup(data, hangul, s, len);
+		if (!leaf) {
+			*pos = s;
+			return 1;
+		}
+		len -= utf8clen(s);
+		s += utf8clen(s);
+	}
+	return 0;
+}
+
 static const struct ext2fs_nls_ops utf8_ops = {
 	.casefold = utf8_casefold,
+	.validate = utf8_validate,
 };
 
 static const struct ext2fs_nls_table nls_utf8 = {
@@ -936,3 +958,9 @@ const struct ext2fs_nls_table *ext2fs_load_nls_table(int encoding)
 
 	return NULL;
 }
+
+int ext2fs_check_encoded_name(const struct ext2fs_nls_table *table,
+			      char *name, size_t len, char **pos)
+{
+	return table->ops->validate(table, name, len, pos);
+}