From patchwork Tue Mar 27 16:29:20 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin LaHaise X-Patchwork-Id: 148993 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 912B5B6EEA for ; Wed, 28 Mar 2012 03:29:34 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753756Ab2C0Q3W (ORCPT ); Tue, 27 Mar 2012 12:29:22 -0400 Received: from kanga.kvack.org ([205.233.56.17]:55075 "EHLO kanga.kvack.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751827Ab2C0Q3U (ORCPT ); Tue, 27 Mar 2012 12:29:20 -0400 Received: by kanga.kvack.org (Postfix, from userid 63042) id 5B2A06B0106; Tue, 27 Mar 2012 12:29:20 -0400 (EDT) Date: Tue, 27 Mar 2012 12:29:20 -0400 From: Benjamin LaHaise To: "David S. Miller" Cc: netdev@vger.kernel.org Subject: [PATCH net/core] dev_forward_skb() should clear skb_iif Message-ID: <20120327162920.GB2367@kvack.org> Mime-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.4.2.2i Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org While investigating another bug, I found that the code on the incoming path in __netif_receive_skb will only set skb->skb_iif if it is already 0. When dev_forward_skb() is used in the case of interfaces like veth, skb_iif may already have been set. Making dev_forward_skb() cause the packet to look more like a newly received packet would seem to the the correct behaviour here, as otherwise the wrong incoming interface can be reported for such a packet. --- net/core/dev.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 0090809..8751f6a 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1597,6 +1597,7 @@ int dev_forward_skb(struct net_device *dev, struct sk_buff *skb) kfree_skb(skb); return NET_RX_DROP; } + skb->skb_iif = 0; skb_set_dev(skb, dev); skb->tstamp.tv64 = 0; skb->pkt_type = PACKET_HOST;