bonding: Add vlan tx offload to hw_enc_features

[ Upstream commit d595b03de2cb0bdf9bcdf35ff27840cc3a37158f ]

As commit 30d8177e8ac7 ("bonding: Always enable vlan tx offload")
said, we should always enable bonding's vlan tx offload, pass the
vlan packets to the slave devices with vlan tci, let them to handle
vlan implementation.

Now if encapsulation protocols like VXLAN is used, skb->encapsulation
may be set, then the packet is passed to vlan device which based on
bonding device. However in netif_skb_features(), the check of
hw_enc_features:

	 if (skb->encapsulation)
                 features &= dev->hw_enc_features;

clears NETIF_F_HW_VLAN_CTAG_TX/NETIF_F_HW_VLAN_STAG_TX. This results
in same issue in commit 30d8177e8ac7 like this:

vlan_dev_hard_start_xmit
  -->dev_queue_xmit
    -->validate_xmit_skb
      -->netif_skb_features //NETIF_F_HW_VLAN_CTAG_TX is cleared
      -->validate_xmit_vlan
        -->__vlan_hwaccel_push_inside //skb->tci is cleared
...
 --> bond_start_xmit
   --> bond_xmit_hash //BOND_XMIT_POLICY_ENCAP34
     --> __skb_flow_dissect // nhoff point to IP header
        -->  case htons(ETH_P_8021Q)
             // skb_vlan_tag_present is false, so
             vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
             //vlan point to ip header wrongly

Fixes: b2a103e6d0af ("bonding: convert to ndo_fix_features")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 11a0e84d3d7cb222e6d45f3763f3bed7715aa6e7..60d0c270af85a9b8c8b71ca21479f3e66634422b 100644 (file)
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1108,7 +1108,9 @@ static void bond_compute_features(struct bonding *bond)
 
 done:
        bond_dev->vlan_features = vlan_features;
-       bond_dev->hw_enc_features = enc_features | NETIF_F_GSO_ENCAP_ALL;
+       bond_dev->hw_enc_features = enc_features | NETIF_F_GSO_ENCAP_ALL |
+                                   NETIF_F_HW_VLAN_CTAG_TX |
+                                   NETIF_F_HW_VLAN_STAG_TX;
        bond_dev->gso_max_segs = gso_max_segs;
        netif_set_gso_max_size(bond_dev, gso_max_size);