From patchwork Wed May 25 17:30:29 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 626341 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 3rFK8T6WwLz9sDD; Thu, 26 May 2016 03:31:53 +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 1b5ces-0007Ev-Os; Wed, 25 May 2016 17:31:50 +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 1b5ceR-00070w-Pp for kernel-team@lists.ubuntu.com; Wed, 25 May 2016 17:31:23 +0000 Received: from 1.general.kamal.us.vpn ([10.172.68.52] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1b5ceR-0005b4-AZ; Wed, 25 May 2016 17:31:23 +0000 Received: from kamal by fourier with local (Exim 4.86_2) (envelope-from ) id 1b5ceO-0005Nv-LB; Wed, 25 May 2016 10:31:20 -0700 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 3.19.y-ckt 26/40] route: do not cache fib route info on local routes with oif Date: Wed, 25 May 2016 10:30:29 -0700 Message-Id: <1464197443-20056-27-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1464197443-20056-1-git-send-email-kamal@canonical.com> References: <1464197443-20056-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Cc: Allain Legacy , Kamal Mostafa , "David S . Miller" 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 3.19.8-ckt22 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Chris Friesen [ Upstream commit d6d5e999e5df67f8ec20b6be45e2229455ee3699 ] For local routes that require a particular output interface we do not want to cache the result. Caching the result causes incorrect behaviour when there are multiple source addresses on the interface. The end result being that if the intended recipient is waiting on that interface for the packet he won't receive it because it will be delivered on the loopback interface and the IP_PKTINFO ipi_ifindex will be set to the loopback interface as well. This can be tested by running a program such as "dhcp_release" which attempts to inject a packet on a particular interface so that it is received by another program on the same board. The receiving process should see an IP_PKTINFO ipi_ifndex value of the source interface (e.g., eth1) instead of the loopback interface (e.g., lo). The packet will still appear on the loopback interface in tcpdump but the important aspect is that the CMSG info is correct. Sample dhcp_release command line: dhcp_release eth1 192.168.204.222 02:11:33:22:44:66 Signed-off-by: Allain Legacy Signed off-by: Chris Friesen Reviewed-by: Julian Anastasov Signed-off-by: David S. Miller Signed-off-by: Kamal Mostafa --- net/ipv4/route.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index e7e7cd8..5de9acd 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1964,6 +1964,18 @@ static struct rtable *__mkroute_output(const struct fib_result *res, */ if (fi && res->prefixlen < 4) fi = NULL; + } else if ((type == RTN_LOCAL) && (orig_oif != 0) && + (orig_oif != dev_out->ifindex)) { + /* For local routes that require a particular output interface + * we do not want to cache the result. Caching the result + * causes incorrect behaviour when there are multiple source + * addresses on the interface, the end result being that if the + * intended recipient is waiting on that interface for the + * packet he won't receive it because it will be delivered on + * the loopback interface and the IP_PKTINFO ipi_ifindex will + * be set to the loopback interface as well. + */ + fi = NULL; } fnhe = NULL;