From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964930Ab2B1BH5 (ORCPT ); Mon, 27 Feb 2012 20:07:57 -0500 Received: from mail-pw0-f46.google.com ([209.85.160.46]:37330 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964871Ab2B1BHx (ORCPT ); Mon, 27 Feb 2012 20:07:53 -0500 Authentication-Results: mr.google.com; spf=pass (google.com: domain of gregkh@linuxfoundation.org designates 10.68.216.129 as permitted sender) smtp.mail=gregkh@linuxfoundation.org MIME-Version: 1.0 Message-Id: <20120228010209.362485044@linuxfoundation.org> User-Agent: quilt/0.51-17.1 Date: Mon, 27 Feb 2012 17:02:35 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Shawn Lu , Eric Dumazet , "David S. Miller" Subject: [ 32/73] tcp_v4_send_reset: binding oif to iif in no sock case In-Reply-To: <20120228010246.GA24299@kroah.com> 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: Shawn Lu [ Upstream commit e2446eaab5585555a38ea0df4e01ff313dbb4ac9 ] Binding RST packet outgoing interface to incoming interface for tcp v4 when there is no socket associate with it. when sk is not NULL, using sk->sk_bound_dev_if instead. (suggested by Eric Dumazet). This has few benefits: 1. tcp_v6_send_reset already did that. 2. This helps tcp connect with SO_BINDTODEVICE set. When connection is lost, we still able to sending out RST using same interface. 3. we are sending reply, it is most likely to be succeed if iif is used Signed-off-by: Shawn Lu Acked-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_ipv4.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -650,6 +650,11 @@ static void tcp_v4_send_reset(struct soc arg.iov[0].iov_len, IPPROTO_TCP, 0); arg.csumoffset = offsetof(struct tcphdr, check) / 2; arg.flags = (sk && inet_sk(sk)->transparent) ? IP_REPLY_ARG_NOSRCCHECK : 0; + /* When socket is gone, all binding information is lost. + * routing might fail in this case. using iif for oif to + * make sure we can deliver it + */ + arg.bound_dev_if = sk ? sk->sk_bound_dev_if : inet_iif(skb); net = dev_net(skb_dst(skb)->dev); ip_send_reply(net->ipv4.tcp_sock, skb, ip_hdr(skb)->saddr,