From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753284AbcL0KBl (ORCPT ); Tue, 27 Dec 2016 05:01:41 -0500 Received: from mail-lf0-f43.google.com ([209.85.215.43]:36236 "EHLO mail-lf0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752654AbcL0KBc (ORCPT ); Tue, 27 Dec 2016 05:01:32 -0500 Subject: Re: [PATCH] net: fix incorrect original ingress device index in PKTINFO To: Wei Zhang , davem@davemloft.net, kuznet@ms2.inr.ac.ru, jmorris@namei.org, yoshfuji@linux-ipv6.org, kaber@trash.net References: <1482825138-2125-1-git-send-email-asuka.com@163.com> Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org From: Sergei Shtylyov Message-ID: Date: Tue, 27 Dec 2016 13:01:29 +0300 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <1482825138-2125-1-git-send-email-asuka.com@163.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello! On 12/27/2016 10:52 AM, Wei Zhang wrote: > When we send a packet for our own local address on a non-loopback interface > (e.g. eth0), due to the change had been introduced from commit 0b922b7a829c > ("net: original ingress device index in PKTINFO"), the original ingress > device index would be set as the loopback interface. However, the packet > should be considered as if it is being arrived via the sending interface > (eth0), otherwise it would break the expectation of the userspace > application (e.g. the DHCPRELEASE message from dhcp_release binary would > be ignored by the dnsmasq daemon) > > Signed-off-by: Wei Zhang > --- > net/ipv4/ip_sockglue.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c > index b8a2d63..b6a6d35 100644 > --- a/net/ipv4/ip_sockglue.c > +++ b/net/ipv4/ip_sockglue.c > @@ -1202,8 +1202,13 @@ void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb) > * which has interface index (iif) as the first member of the > * underlying inet{6}_skb_parm struct. This code then overlays > * PKTINFO_SKB_CB and in_pktinfo also has iif as the first > - * element so the iif is picked up from the prior IPCB > + * element so the iif is picked up from the prior IPCB except > + * iif is loopback interface which the packet should be Tail space. > + * considered as if it is being arrived via the sending interface > */ > + if (pktinfo->ipi_ifindex == LOOPBACK_IFINDEX) { > + pktinfo->ipi_ifindex = inet_iif(skb); > + } {} not needed here. > pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb); > } else { > pktinfo->ipi_ifindex = 0; MBR, Sergei