Slashes in filenames?

[Robert Thurlow]

In <26038 at adm.brl.mil> STEINKEL%CAR1 at leav-emh.army.mil writes:

>If the prohibition on slashes in filenames is enforced by the kernel, how
>the bleep does NFS get them in there?

The NFS server on BSD/Sun systems is implemented as a module that calls
virtual file system (VFS) operations directly; the VFS is a layer below
the system call interface.  Since many of the old, inviolable firewalls
are implemented at the system call level, they had to be duplicated in
the NFS server logic.  Sun's initial implementation didn't catch a
number of these, and neither Sun nor the industry as a whole has kept up
with closing them as soon as they were found.  The slash issue is old
news; other things like the server permitting mknod()s by non-root
users are still being found.  One of the things that makes it tougher
is the fact that Unix clients can't send you such a request, since they
still have the firewall in the syscall.

Rob T
--
Rob Thurlow, thurlow at convex.com
An employee and not a spokesman for Convex Computer Corp., Dallas, TX