Re: [PATCH] decnet: fix shutdown parameter checking

Hi,

On Fri, 2012-08-31 at 15:57 -0400, David Miller wrote:

From: Steven Whitehouse <redacted>
Date: Mon, 27 Aug 2012 10:16:41 +0100

quoted

On Sun, 2012-08-26 at 22:37 -0400, Xi Wang wrote:

quoted

The allowed value of "how" is SHUT_RD/SHUT_WR/SHUT_RDWR (0/1/2),
rather than SHUTDOWN_MASK (3).

Signed-off-by: Xi Wang <xi.wang@gmail.com>

Acked-by: Steven Whitehouse <redacted>

Applied to net-next.

quoted

Although it could be argued that we should also continue to accept the
value 3 just in case there is any userland software out there which
sends that value,

True, but this is a rather standard BSD socket interface with a very
specific small set of legitimate input parameters.  Allowing
deviation, even for compatability for specific protocols, is largely
unwise.

Yes, I'd agree on the whole, and certainly if this was a recent
addition. However since this code has been around for somewhere close to
16 years now, I'd say that means that either (a) nobody calls shutdown
for DECnet or (b) existing users are buggy too.

We do have a precedent for this kind of compatibility, such as the AX.25
use of SOCK_SEQPACKET.

However, I'm not overly worried and we'll soon know if it will cause any
problems or not,

Steve.