Mail Archives: cygwin/2008/10/13/11:49:54
On Oct 10 20:34, Eric Blake wrote:
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> I'm just as stumped as Bruno on this issue, and don't know if it
> represents a bug in cygwin1.dll.
>
> - -------- Original Message --------
> [http://lists.gnu.org/archive/html/bug-gnulib/2008-10/msg00195.html]
>
> The test-copy-acl.sh test fails for me on Cygwin.
>
> There appears to be a weird interaction between setting a file mode (chmod)
> and setting an ACL. Although on this platform the ACL has entries that
> correspond to user/group/other, the mode is *not* part of the ACL for all
> files.
>
> The test case showing that 'chmod' influences the ACL is this:
>
> tmpfile4 is a regular file. One calls acl or facl on it with these entries:
> (gdb) print entries[0]
> $5 = {a_type = 1, a_id = 1006, a_perm = 6}
> (gdb) print entries[1]
> $6 = {a_type = 4, a_id = 513, a_perm = 0}
> (gdb) print entries[2]
> $7 = {a_type = 8, a_id = 0, a_perm = 1}
> (gdb) print entries[3]
> $8 = {a_type = 16, a_id = 4294967295, a_perm = 7}
> (gdb) print entries[4]
> $9 = {a_type = 32, a_id = 4294967295, a_perm = 4}
>
> Then "getfacl tmpfile4" shows these entries:
> user::rw-
> group::---
> group:root:--x
> mask:rwx
> other:r--
> Looks all right. Then do a chmod 604 on it. Then "getfacl tmpfile4" shows
> this:
> user::rw-
> group::r--
> group:root:--x
> mask:rwx
> other:r--
> The "r--" for 'other' has been ORed to the permissions for 'group'!
> [...etc...]
The problem results from the fact that, in contrast to chmod, setfacl
does not create deny ACEs in case "other" and/or the group have more
rights than the group and/or the owner of the file. I described the
basic problem of mapping POSIX permissions to Windows ACLs years ago in
http://cygwin.com/cygwin-ug-net/ntsec.html#ntsec-mapping
setfacl doesn't create deny ACEs and, unfortunately, even removes them
when creating a new file ACL. Yes, that needs reworking at one point.
Corinna
--
Corinna Vinschen Please, send mails regarding Cygwin to
Cygwin Project Co-Leader cygwin AT cygwin DOT com
Red Hat
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