Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752454AbcL2Emj (ORCPT ); Wed, 28 Dec 2016 23:42:39 -0500 Received: from mail-pg0-f51.google.com ([74.125.83.51]:33285 "EHLO mail-pg0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752161AbcL2Emh (ORCPT ); Wed, 28 Dec 2016 23:42:37 -0500 Subject: Re: [PATCH] net: fix incorrect original ingress device index in PKTINFO To: David Miller , asuka.com@163.com References: <1482832344-24760-1-git-send-email-asuka.com@163.com> <20161227.140313.1837464529059496066.davem@davemloft.net> Cc: kuznet@ms2.inr.ac.ru, jmorris@namei.org, yoshfuji@linux-ipv6.org, kaber@trash.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org From: David Ahern Message-ID: Date: Wed, 28 Dec 2016 21:42:34 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <20161227.140313.1837464529059496066.davem@davemloft.net> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2542 Lines: 63 On 12/27/16 12:03 PM, David Miller wrote: > From: Wei Zhang > Date: Tue, 27 Dec 2016 17:52:24 +0800 > >> 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, since it come from lo which >> is not the interface dnsmasq bind to) >> Add a Fixes line before the sign-off: Fixes: 0b922b7a829c ("net: original ingress device index in PKTINFO") >> Signed-off-by: Wei Zhang > > When you are fixing a problem introduced by another change, always CC: > the author of that change as I have done so here. > > David, please take a look at this, thanks. > >> --- >> net/ipv4/ip_sockglue.c | 8 +++++++- >> 1 file changed, 7 insertions(+), 1 deletion(-) >> >> diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c >> index b8a2d63..76d78a7 100644 >> --- a/net/ipv4/ip_sockglue.c >> +++ b/net/ipv4/ip_sockglue.c >> @@ -1202,8 +1202,14 @@ 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 >> + * considered as if it is being arrived via the sending >> + * interface That comment change could use an adjustment (adjust to fit with in the 80 columns): element so the iif is picked up from the prior IPCB. If iif is the loopback interface, then return the sending interface (e.g., process binds socket to eth0 for Tx which is redirected to loopback in the rtable/dst). >> */ >> + if (pktinfo->ipi_ifindex == LOOPBACK_IFINDEX) >> + pktinfo->ipi_ifindex = inet_iif(skb); >> + >> pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb); >> } else { >> pktinfo->ipi_ifindex = 0; The actual change looks ok to me. Acked-by: David Ahern