From patchwork Thu Apr 20 21:02:33 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: jorge.niedbalski@canonical.com X-Patchwork-Id: 753010 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 3w8BCx1Vsyz9s7g; Fri, 21 Apr 2017 07:03:09 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1d1JEI-0006JX-2B; Thu, 20 Apr 2017 21:03:06 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1d1JEE-0006I9-6B for kernel-team@lists.ubuntu.com; Thu, 20 Apr 2017 21:03:02 +0000 Received: from 1.general.niedbalski.us.vpn ([10.172.67.66] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1d1JEC-00037U-GD for kernel-team@lists.ubuntu.com; Thu, 20 Apr 2017 21:03:01 +0000 From: jorge.niedbalski@canonical.com To: kernel-team@lists.ubuntu.com Subject: [PATCH Yakkety SRU 1/1] net: fix incorrect original ingress device index in PKTINFO Date: Thu, 20 Apr 2017 18:02:33 -0300 Message-Id: <1492722153-27204-2-git-send-email-jorge.niedbalski@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1492722153-27204-1-git-send-email-jorge.niedbalski@canonical.com> References: <1492722153-27204-1-git-send-email-jorge.niedbalski@canonical.com> X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com From: Wei Zhang 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) Fixes: 0b922b7a829c ("net: original ingress device index in PKTINFO") Acked-by: David Ahern Signed-off-by: Wei Zhang Signed-off-by: David S. Miller Signed-off-by: Jorge Niedbalski Acked-by: Seth Forshee --- 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 11ef96e..5519205 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -1199,8 +1199,14 @@ 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. 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;