From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH v3 2/2] macvtap: Allow tap features change when IFF_VNET_HDR is disabled. Date: Thu, 15 Aug 2013 20:33:47 +0300 Message-ID: <20130815173347.GA10265@redhat.com> References: <1376586173-4242-1-git-send-email-vyasevic@redhat.com> <1376586173-4242-3-git-send-email-vyasevic@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org To: Vlad Yasevich Return-path: Received: from mx1.redhat.com ([209.132.183.28]:22290 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757969Ab3HORcC (ORCPT ); Thu, 15 Aug 2013 13:32:02 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r7FHW1gr015688 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 15 Aug 2013 13:32:01 -0400 Content-Disposition: inline In-Reply-To: <1376586173-4242-3-git-send-email-vyasevic@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Aug 15, 2013 at 01:02:53PM -0400, Vlad Yasevich wrote: > When the user turns off IFF_VNET_HDR flag, attempts to change > offload features via TUNSETOFFLOAD do not work. This could cause > GSO packets to be delivered to the user when the user is > not prepared to handle them. > > To solve, allow processing of TUNSETOFFLOAD when IFF_VNET_HDR is > disabled. Also, take the setting of IFF_VNET_HDR into consideration > when determining the feature set to apply to incommig traffic. > If IFF_VNET_HDR is set, we use user-specfied feature set. if the > IFF_VNET_HDR is clear, we mask off all tun-specific offload features, > since user can not be notified of the possbile offloads. > > Signed-off-by: Vlad Yasevich > --- > drivers/net/macvtap.c | 30 ++++++++++++++++++++++++------ > 1 file changed, 24 insertions(+), 6 deletions(-) > > diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c > index 8121358..df45a59 100644 > --- a/drivers/net/macvtap.c > +++ b/drivers/net/macvtap.c > @@ -269,6 +269,28 @@ static void macvtap_del_queues(struct net_device *dev) > sock_put(&qlist[j]->sk); > } > > +/* Determine features to be applied to the packet as it /* * Please use comments * like this */ > + * gets sent to the tap. The features depend on the offloads > + * set by user and by whether or not IFF_VNET_HDR is enabled. > + */ > +static netdev_features_t macvtap_skb_features(struct sk_buff *skb, > + struct macvtap_queue *q) > +{ > + struct macvlan_dev *vlan = netdev_priv(skb->dev); > + netdev_features_t features = netif_skb_features(skb); > + > + /* If VNET_HDR is enabled, user can receive offload info so > + * use user-specified tap_features. > + * Otherwise, mask off all tap offload features. > + */ > + if (q->flags & IFF_VNET_HDR) > + features &= vlan->tap_features; > + else > + features &= ~TUN_OFFLOADS; > + > + return features; > +} > + Okay, but this means we need to do netdev_update_features on SETIFF since it changes q->flags. > /* > * Forward happens for data that gets sent from one macvlan > * endpoint to another one in bridge mode. We just take > @@ -276,9 +298,9 @@ static void macvtap_del_queues(struct net_device *dev) > */ > static int macvtap_forward(struct net_device *dev, struct sk_buff *skb) > { > - struct macvlan_dev *vlan = netdev_priv(dev); > struct macvtap_queue *q = macvtap_get_queue(dev, skb); > netdev_features_t features; > + > if (!q) > goto drop; > > @@ -289,7 +311,7 @@ static int macvtap_forward(struct net_device *dev, struct sk_buff *skb) > /* Apply the forward feature mask so that we perform segmentation > * according to users wishes. > */ > - features = netif_skb_features(skb) & vlan->tap_features; > + features = macvtap_skb_features(skb, q); > if (netif_needs_gso(skb, features)) { > struct sk_buff *segs = __skb_gso_segment(skb, features, false); > > @@ -1161,10 +1183,6 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd, > TUN_F_TSO_ECN | TUN_F_UFO)) > return -EINVAL; > > - /* TODO: only accept frames with the features that > - got enabled for forwarded frames */ > - if (!(q->flags & IFF_VNET_HDR)) > - return -EINVAL; > rtnl_lock(); > ret = set_offload(q, arg); > rtnl_unlock(); > -- > 1.8.1.4