[PATCH 10/12] xfsprogs: use printable characters for obfuscated filenames

[Alex Elder]

There is probably not much need for an extreme amount of randomness
in the obfuscated names produced in metadumps.  Limit the character
set used for (most of) these filenames to printable characters
rather than every permitted byte.  The result makes metadumps
a bit more natural to work with.

I chose the set of all upper- and lower-case letters, digits, and
the dash and underscore for the alphabet.  It could easily be
expanded to include others.

Signed-off-by: Alex Elder <aelder at sgi.com>

---
 db/metadump.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

Index: b/db/metadump.c
===================================================================
--- a/db/metadump.c
+++ b/db/metadump.c
@@ -377,12 +377,11 @@ clear_nametable(void)
 static inline uchar_t
 random_filename_char(void)
 {
-	uchar_t			c;
+	static uchar_t filename_alphabet[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+						"abcdefghijklmnopqrstuvwxyz"
+						"0123456789-_";
 
-	do {
-		c = random() % 127 + 1;
-	} while (c == '/');
-	return c;
+	return filename_alphabet[random() % (sizeof filename_alphabet - 1)];
 }
 
 /*