Revert "macvlan : fix checksums error when we are in bridge mode"

[ Upstream commit f114890cdf84d753f6b41cd0cc44ba51d16313da ]

This reverts commit 12a2856b604476c27d85a5f9a57ae1661fc46019.
The commit above doesn't appear to be necessary any more as the
checksums appear to be correctly computed/validated.

Additionally the above commit breaks kvm configurations where
one VM is using a device that support checksum offload (virtio) and
the other VM does not.
In this case, packets leaving virtio device will have CHECKSUM_PARTIAL
set.  The packets is forwarded to a macvtap that has offload features
turned off.  Since we use CHECKSUM_UNNECESSARY, the host does does not
update the checksum and thus a bad checksum is passed up to
the guest.

CC: Daniel Lezcano <daniel.lezcano@free.fr>
CC: Patrick McHardy <kaber@trash.net>
CC: Andrian Nord <nightnord@gmail.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Michael S. Tsirkin <mst@redhat.com>
CC: Jason Wang <jasowang@redhat.com>
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 06eba6e480c97a7b37476ba45d129f3e43d91057..6ce640d65f91e4026988b037ef82c4296c86ed27 100644 (file)
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -261,11 +261,9 @@ static int macvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
        const struct macvlan_dev *vlan = netdev_priv(dev);
        const struct macvlan_port *port = vlan->port;
        const struct macvlan_dev *dest;
-       __u8 ip_summed = skb->ip_summed;
 
        if (vlan->mode == MACVLAN_MODE_BRIDGE) {
                const struct ethhdr *eth = (void *)skb->data;
-               skb->ip_summed = CHECKSUM_UNNECESSARY;
 
                /* send to other bridge ports directly */
                if (is_multicast_ether_addr(eth->h_dest)) {
@@ -283,7 +281,6 @@ static int macvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
        }
 
 xmit_world:
-       skb->ip_summed = ip_summed;
        skb->dev = vlan->lowerdev;
        return dev_queue_xmit(skb);
 }