Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932206AbbHCQZz (ORCPT ); Mon, 3 Aug 2015 12:25:55 -0400 Received: from mail-io0-f180.google.com ([209.85.223.180]:36117 "EHLO mail-io0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754480AbbHCQZx (ORCPT ); Mon, 3 Aug 2015 12:25:53 -0400 MIME-Version: 1.0 In-Reply-To: <1438484942.277866.12350@glenng-linux.sea.corp.google.com> References: <1438484942.277866.12350@glenng-linux.sea.corp.google.com> Date: Mon, 3 Aug 2015 09:25:53 -0700 Message-ID: Subject: Re: [PATCH] openvswitch: Fix L4 checksum handling when dealing with IP fragments From: Pravin Shelar To: Glenn Griffin Cc: "David S. Miller" , netdev , "dev@openvswitch.org" , LKML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1665 Lines: 39 On Sat, Aug 1, 2015 at 6:31 PM, Glenn Griffin wrote: > openvswitch modifies the L4 checksum of a packet when modifying > the ip address. When an IP packet is fragmented only the first > fragment contains an L4 header and checksum. Prior to this change > openvswitch would modify all fragments, modifying application data > in non-first fragments, causing checksum failures in the > reassembled packet. > > Signed-off-by: Glenn Griffin Patch looks good. I have one following comment. > --- > net/openvswitch/actions.c | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c > index 8a8c0b8..bfffb1a 100644 > --- a/net/openvswitch/actions.c > +++ b/net/openvswitch/actions.c > @@ -273,28 +273,36 @@ static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *flow_key, > return 0; > } > > -static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh, > - __be32 *addr, __be32 new_addr) > +static void update_ip_l4_checksum(struct sk_buff *skb, struct iphdr *nh, > + __be32 addr, __be32 new_addr) > { > int transport_len = skb->len - skb_transport_offset(skb); > > + if (ntohs(nh->frag_off) & IP_OFFSET) > + return; It is efficient to check frag-offset in network byte order. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/