From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Goff Subject: [PATCH] gre: Fix MTU calculation for bound GRE tunnels Date: Fri, 14 Aug 2009 11:37:58 -0700 Message-ID: <20090814183758.GA21197@boeing.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: netdev@vger.kernel.org Return-path: Received: from blv-smtpout-01.boeing.com ([130.76.32.69]:59563 "EHLO blv-smtpout-01.boeing.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754415AbZHNSw1 (ORCPT ); Fri, 14 Aug 2009 14:52:27 -0400 Received: from slb-av-01.boeing.com (slb-av-01.boeing.com [129.172.13.4]) by blv-smtpout-01.ns.cs.boeing.com (8.14.0/8.14.0/8.14.0/SMTPOUT) with ESMTP id n7EIbxQ4021293 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Fri, 14 Aug 2009 11:38:00 -0700 (PDT) Received: from slb-av-01.boeing.com (localhost [127.0.0.1]) by slb-av-01.boeing.com (8.14.0/8.14.0/DOWNSTREAM_RELAY) with ESMTP id n7EIbx5t029850 for ; Fri, 14 Aug 2009 11:37:59 -0700 (PDT) Received: from packet.blv.boeing.com (packet.blv.boeing.com [130.42.97.136]) by slb-av-01.boeing.com (8.14.0/8.14.0/UPSTREAM_RELAY) with SMTP id n7EIbwAd029832 for ; Fri, 14 Aug 2009 11:37:58 -0700 (PDT) Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: The GRE header length should be subtracted when the tunnel MTU is calculated. This just corrects for the associativity change introduced by commit 42aa916265d740d66ac1f17290366e9494c884c2. Signed-off-by: Tom Goff --- net/ipv4/ip_gre.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index cb4a0f4..82c11dd 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -951,7 +951,7 @@ static int ipgre_tunnel_bind_dev(struct net_device *dev) addend += 4; } dev->needed_headroom = addend + hlen; - mtu -= dev->hard_header_len - addend; + mtu -= dev->hard_header_len + addend; if (mtu < 68) mtu = 68; -- 1.6.0.6