From mboxrd@z Thu Jan 1 00:00:00 1970 From: Toshiaki Makita Subject: Re: [PATCH net v2] macvtap: fix network header pointer for VLAN tagged pkts Date: Tue, 21 Jul 2015 23:44:58 +0900 Message-ID: <55AE5AEA.5010802@gmail.com> References: <1437463115-2881-1-git-send-email-ivecera@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-2022-jp Content-Transfer-Encoding: 7bit Cc: vyasevich@gmail.com To: Ivan Vecera , netdev@vger.kernel.org Return-path: Received: from mail-pa0-f54.google.com ([209.85.220.54]:36349 "EHLO mail-pa0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932067AbbGUOpD (ORCPT ); Tue, 21 Jul 2015 10:45:03 -0400 Received: by pachj5 with SMTP id hj5so121623064pac.3 for ; Tue, 21 Jul 2015 07:45:02 -0700 (PDT) In-Reply-To: <1437463115-2881-1-git-send-email-ivecera@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: On 15/07/21 (火) 16:18, Ivan Vecera wrote: > Network header is set with offset ETH_HLEN but it is not true for VLAN > (multiple-)tagged and results in checksum issues in lower devices. > > v2: leave skb->protocol untouched (thx Vlad), comment added > > Signed-off-by: Ivan Vecera > --- > drivers/net/macvtap.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c > index 3b933bb..b75776b 100644 > --- a/drivers/net/macvtap.c > +++ b/drivers/net/macvtap.c > @@ -796,6 +796,13 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m, > skb_reset_mac_header(skb); > skb->protocol = eth_hdr(skb)->h_proto; > > + /* Move network header to the right position for VLAN tagged packets */ > + if (skb_vlan_tagged(skb)) { I guess you don't need the condition skb_vlan_tag_present(skb), i.e., if (skb->protocol == htons(ETH_P_8021Q) || skb->protocol == htons(ETH_P_8021AD)) > + int depth; > + __vlan_get_protocol(skb, skb->protocol, &depth); __vlan_get_protocol() can fail, and then, depth will not be initialized. > + skb_set_network_header(skb, depth); I think you should set network_header after skb_probe_transport_header(). It calls skb_flow_dissect_flow_keys(), which seems to expect network_header to be ETH_HLEN. Toshiaki Makita