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>

diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
index 852f874e58171c82b0e950fa46cde9922aa1887e..2a74199236d8398575beb8dd833bbca3ba4c84fd 100644 (file)
--- a/fs/fat/fat_write.c
+++ b/fs/fat/fat_write.c
@@ -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;
-       }
 
-       /* Normalize it */
-       name_len = strlen(filename);
-       if (name_len >= VFAT_MAXLEN_BYTES)
-               /* should return an error? */
-               name_len = VFAT_MAXLEN_BYTES - 1;
+       for (p = filename; *p; ++p) {
+               if ((unsigned char)*p < 0x20)
+                       return -1;
+               if (strchr(illegal, *p))
+                       return -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;
 }