From 7d577c2c191b9fc734fecd67068254f8f04db7e2 Mon Sep 17 00:00:00 2001 From: Ursula Braun Date: Fri, 7 Oct 2016 15:51:47 +0200 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/iucv/af_iucv.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c index 02b45a8e8b357..88d0eaa187492 100644 --- a/net/iucv/af_iucv.c +++ b/net/iucv/af_iucv.c @@ -453,19 +453,27 @@ static void iucv_sever_path(struct sock *sk, int with_user_data) } } -/* Send FIN through an IUCV socket for HIPER transport */ +/* Send controlling flags through an IUCV socket for HIPER transport */ static int iucv_send_ctrl(struct sock *sk, u8 flags) { int err = 0; int blen; struct sk_buff *skb; + u8 shutdown = 0; blen = sizeof(struct af_iucv_trans_hdr) + ETH_HLEN; + if (sk->sk_shutdown & SEND_SHUTDOWN) { + /* controlling flags should be sent anyway */ + shutdown = sk->sk_shutdown; + sk->sk_shutdown &= RCV_SHUTDOWN; + } skb = sock_alloc_send_skb(sk, blen, 1, &err); if (skb) { skb_reserve(skb, blen); err = afiucv_hs_send(NULL, sk, skb, flags); } + if (shutdown) + sk->sk_shutdown = shutdown; return err; } -- 2.39.5