bug in masked_match function

[Tomoki AONO]

I found this suspisious case (and described shortly in
Samba-JP), so I'll explain more.

In <20030310164748.6f0dacc2.yasuma at miraclelinux.com>,
yasuma at miraclelinux.com wrote:

>> The masked_match function in lib/access.c is wrong.(CVS HEAD and 2_2)

This case matches if CIDR-like notation specified in hosts
allow/deny (ex. '10.0.0.0/23') only. This is not case if
specified with <network>/<subnet mask>. (ex. '10.0.0.0/255.255.254.0')

I cite more lines in lib/access.c:
    33	        if (strlen(slash + 1) > 2) {
    34	                mask = interpret_addr(slash + 1);
    35	        } else {
    36			mask = (uint32)((ALLONES << atoi(slash + 1)) ^ ALLONES);
    37	        }

>> Example: hosts allow = 10.0.0.0/23
>> 
>> This produces following result. This isn't mask.
>> mask = 0000 0000 0111 1111 1111 1111 1111 1111

In case '10.0.0.0/255.255.254.0', program execute line 34
and returns:
mask = 1111 1111 1111 1111 1111 1110 0000 0000

>> I don't know why this change was made.
>> http://cvs.samba.org/cgi-bin/cvsweb/samba/source/lib/access.c.diff?r1=1.19.4.12&r2=1.19.4.13

I think reverting change in line 36 (reverse shift
direction) or replacing '^'(XOR) to '&'(AND) would solve
this case. Am I right?

Patch (I prefer replacing '^' to '&') follows:

Index: lib/access.c
===================================================================
RCS file: /cvsroot/samba/source/lib/access.c,v
retrieving revision 1.35
diff -u -u -w -r1.35 access.c
--- lib/access.c	12 Nov 2002 23:15:49 -0000	1.35
+++ lib/access.c	14 Mar 2003 10:43:09 -0000
@@ -33,7 +33,7 @@
         if (strlen(slash + 1) > 2) {
                 mask = interpret_addr(slash + 1);
         } else {
-		mask = (uint32)((ALLONES << atoi(slash + 1)) ^ ALLONES);
+		mask = (uint32)((ALLONES << atoi(slash + 1)) & ALLONES);
         }
 
 	if (net == INADDR_NONE || mask == INADDR_NONE) {

----
Tomoki AONO	(aono at cc.osaka-kyoiku.ac.jp)