fs: fat: correct file name normalization

File names may not contain control characters (< 0x20).
Simplify the coding.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
This commit is contained in:
Heinrich Schuchardt 2019-05-12 09:59:18 +02:00 committed by Tom Rini
parent 7c7919cd07
commit 7b437807ee

View File

@ -1009,40 +1009,32 @@ again:
return 0;
}
/**
* normalize_longname() - check long file name and convert to lower case
*
* We assume here that the FAT file system is using an 8bit code page.
* Linux typically uses CP437, EDK2 assumes CP1250.
*
* @l_filename: preallocated buffer receiving the normalized name
* @filename: filename to normalize
* Return: 0 on success, -1 on failure
*/
static int normalize_longname(char *l_filename, const char *filename)
{
const char *p, legal[] = "!#$%&\'()-.@^`_{}~";
unsigned char c;
int name_len;
/* Check that the filename is valid */
for (p = filename; p < filename + strlen(filename); p++) {
c = *p;
if (('0' <= c) && (c <= '9'))
continue;
if (('A' <= c) && (c <= 'Z'))
continue;
if (('a' <= c) && (c <= 'z'))
continue;
if (strchr(legal, c))
continue;
/* extended code */
if ((0x80 <= c) && (c <= 0xff))
continue;
const char *p, illegal[] = "<>:\"/\\|?*";
if (strlen(filename) >= VFAT_MAXLEN_BYTES)
return -1;
for (p = filename; *p; ++p) {
if ((unsigned char)*p < 0x20)
return -1;
if (strchr(illegal, *p))
return -1;
}
/* Normalize it */
name_len = strlen(filename);
if (name_len >= VFAT_MAXLEN_BYTES)
/* should return an error? */
name_len = VFAT_MAXLEN_BYTES - 1;
memcpy(l_filename, filename, name_len);
l_filename[name_len] = 0; /* terminate the string */
downcase(l_filename, INT_MAX);
strcpy(l_filename, filename);
downcase(l_filename, VFAT_MAXLEN_BYTES);
return 0;
}