UFS label limitations

[Rick C. Petty]

I always found it strange that when creating or changing a UFS label, you
were restricted to alphanumeric characters.  I really wanted some sort of
separator, so I took a look at the code.  Since the checks use isalnum(3)
it is possible to create labels that are not 7-bit clean, depending upon
your locale.  After further investigation, I can't see any reason (in
geom_label or otherwise) that the characters should be restricted in such
a way.

I applied the attached (inline) patch and have had no troubles creating,
editing, or mounting via UFS labels.  The patch allows you to create
labels with any characters except '/' (for obvious reasons) and should
work with most locales (with the tiny exception that multibyte characters
which use 0x2F in subsequent bytes should be rejected, since geom_label
is locale-agnostic).

Would someone mind reviewing and committing this patch?  Thank you,

-- Rick C. Petty


--- src/sbin/newfs/newfs.c.orig	2007-03-02 14:07:59.000000000 -0600
+++ src/sbin/newfs/newfs.c	2008-12-12 19:13:19.000000000 -0600
@@ -168,11 +168,10 @@
 		case 'L':
 			volumelabel = optarg;
 			i = -1;
-			while (isalnum(volumelabel[++i]));
-			if (volumelabel[i] != '\0') {
-				errx(1, "bad volume label. Valid characters are alphanumerics.");
-			}
-			if (strlen(volumelabel) >= MAXVOLLEN) {
+			while ((ch = volumelabel[++i]) != '\0')
+				if (ch == '/')
+					errx(1, "bad volume label. \"/\" not allowed.");
+			if (i >= MAXVOLLEN) {
 				errx(1, "bad volume label. Length is longer than %d.",
 				    MAXVOLLEN);
 			}
--- src/sbin/tunefs/tunefs.c.orig	2008-02-26 14:25:35.000000000 -0600
+++ src/sbin/tunefs/tunefs.c	2008-12-12 19:19:33.000000000 -0600
@@ -153,13 +153,12 @@
 			name = "volume label";
 			Lvalue = optarg;
 			i = -1;
-			while (isalnum(Lvalue[++i]));
-			if (Lvalue[i] != '\0') {
+			while ((ch = Lvalue[++i]) != '\0')
+				if (ch == '/')
 				errx(10,
-				"bad %s. Valid characters are alphanumerics.",
+					"bad %s. \"/\" not allowed.",
 				    name);
-			}
-			if (strlen(Lvalue) >= MAXVOLLEN) {
+			if (i >= MAXVOLLEN) {
 				errx(10, "bad %s. Length is longer than %d.",
 				    name, MAXVOLLEN - 1);
 			}