From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH 08/10] tun: Re-uanble UFO support. Date: Thu, 18 Dec 2014 00:33:40 +0200 Message-ID: <20141217223340.GB30969@redhat.com> References: <1418840455-22598-1-git-send-email-vyasevic@redhat.com> <1418840455-22598-9-git-send-email-vyasevic@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, ben@decadent.org.uk, stefanha@redhat.com, virtualization@lists.linux-foundation.org To: Vladislav Yasevich Return-path: Content-Disposition: inline In-Reply-To: <1418840455-22598-9-git-send-email-vyasevic@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org List-Id: netdev.vger.kernel.org subs: re-enable On Wed, Dec 17, 2014 at 01:20:53PM -0500, Vladislav Yasevich wrote: > Now that UFO is split into v4 and v6 parts, we can bring > back v4 support without any trouble. > > Continue to handle legacy applications by selecting the > IPv6 fragment id but do not change the gso type. Thist s/Thist/this/ > makes sure that two legacy VMs may still communicate. This means IPv6 skbs with UFO (not UFO6) flag set are present in the stack. If possible, I think it would be better to make GSO type correct: UFO6, and then convert to UFO when copying to guest. A similar approach should be possible for OVS? > Based on original work from Ben Hutchings. > > Fixes: 88e0e0e5aa7a ("drivers/net: Disable UFO through virtio") > CC: Ben Hutchings > Signed-off-by: Vladislav Yasevich > --- > drivers/net/tun.c | 26 ++++++++++++++------------ > 1 file changed, 14 insertions(+), 12 deletions(-) > > diff --git a/drivers/net/tun.c b/drivers/net/tun.c > index 9dd3746..8c32fca 100644 > --- a/drivers/net/tun.c > +++ b/drivers/net/tun.c > @@ -175,7 +175,7 @@ struct tun_struct { > struct net_device *dev; > netdev_features_t set_features; > #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \ > - NETIF_F_TSO6) > + NETIF_F_TSO6|NETIF_F_UFO) > > int vnet_hdr_sz; > int sndbuf; > @@ -1152,20 +1152,15 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, > skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; > break; > case VIRTIO_NET_HDR_GSO_UDP: > - { > - static bool warned; > - > - if (!warned) { > - warned = true; > - netdev_warn(tun->dev, > - "%s: using disabled UFO feature; please fix this program\n", > - current->comm); > - } > skb_shinfo(skb)->gso_type = SKB_GSO_UDP; > - if (skb->protocol == htons(ETH_P_IPV6)) > + if (vlan_get_protocol(skb) == htons(ETH_P_IPV6)) { > + /* This allows legacy application to work. > + * Do not change the gso_type as it may > + * not be upderstood by legacy applications. Shouldn't we handle legacy applications when passing packets to userspace? > + */ > ipv6_proxy_select_ident(skb); > + } > break; > - } > default: > tun->dev->stats.rx_frame_errors++; > kfree_skb(skb); > @@ -1273,6 +1268,8 @@ static ssize_t tun_put_user(struct tun_struct *tun, > gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; > else if (sinfo->gso_type & SKB_GSO_TCPV6) > gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; > + else if (sinfo->gso_type & SKB_GSO_UDP) > + gso.gso_type = VIRTIO_NET_HDR_GSO_UDP; > else { > pr_err("unexpected GSO type: " > "0x%x, gso_size %d, hdr_len %d\n", > @@ -1780,6 +1777,11 @@ static int set_offload(struct tun_struct *tun, unsigned long arg) > features |= NETIF_F_TSO6; > arg &= ~(TUN_F_TSO4|TUN_F_TSO6); > } > + > + if (arg & TUN_F_UFO) { > + features |= NETIF_F_UFO; > + arg &= ~TUN_F_UFO; > + } > } > > /* This gives the user a way to test for new features in future by > -- > 1.9.3