Subject: [PATCH] af_iucv: enable control sends in case of SEND_SHUTDOWN

If a socket program has shut down the socket for sending, it can still
receive an undetermined number of packets. The AF_IUCV protocol for
HIPER transport requires sending of a WIN flag from time to time
from the receiver to the sender, otherwise the peer cannot continue
sending. That means sending of control flags must still work, even
though the AF_IUCV socket is shutdown for sending data.
sock_alloc_send_skb() returns with error EPIPE, if socket sk_shutdown
is SEND_SHUTDOWN. Thus this patch temporarily removes the send
shutdown attribute from the socket to enable transfer of control
flags.

Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>