From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2992798Ab2KOEqE (ORCPT ); Wed, 14 Nov 2012 23:46:04 -0500 Received: from mail.kernel.org ([198.145.19.201]:48529 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2992730Ab2KOEKd (ORCPT ); Wed, 14 Nov 2012 23:10:33 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Elliot Hughes , Eric Dumazet , Neal Cardwell , Tom Herbert , "David S. Miller" Subject: [ 26/38] tcp: fix FIONREAD/SIOCINQ Date: Wed, 14 Nov 2012 20:10:23 -0800 Message-Id: <20121115040934.500024361@linuxfoundation.org> X-Mailer: git-send-email 1.8.0.rc3.16.g8ead1bf In-Reply-To: <20121115040932.918082372@linuxfoundation.org> References: <20121115040932.918082372@linuxfoundation.org> User-Agent: quilt/0.60-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit a3374c42aa5f7237e87ff3b0622018636b0c847e ] tcp_ioctl() tries to take into account if tcp socket received a FIN to report correct number bytes in receive queue. But its flaky because if the application ate the last skb, we return 1 instead of 0. Correct way to detect that FIN was received is to test SOCK_DONE. Reported-by: Elliot Hughes Signed-off-by: Eric Dumazet Cc: Neal Cardwell Cc: Tom Herbert Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -481,14 +481,12 @@ int tcp_ioctl(struct sock *sk, int cmd, !tp->urg_data || before(tp->urg_seq, tp->copied_seq) || !before(tp->urg_seq, tp->rcv_nxt)) { - struct sk_buff *skb; answ = tp->rcv_nxt - tp->copied_seq; - /* Subtract 1, if FIN is in queue. */ - skb = skb_peek_tail(&sk->sk_receive_queue); - if (answ && skb) - answ -= tcp_hdr(skb)->fin; + /* Subtract 1, if FIN was received */ + if (answ && sock_flag(sk, SOCK_DONE)) + answ--; } else answ = tp->urg_seq - tp->copied_seq; release_sock(sk);