Subject: Re: [PATCH] bonding: Add vlan tx offload to hw_enc_features

From: Jay Vosburgh <[email-masked]>
Date: Tue, 06 Aug 2019 09:41:24 -0400

YueHaibing <[email-masked]> wrote:

>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 devicec which based on

	Typo: "devicec"

>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
>
>Signed-off-by: YueHaibing <[email-masked]>

	Looks good to me; should this be tagged with

Fixes: 278339a42a1b ("bonding: propogate vlan_features to bonding master")

	as 30d8177e8ac7 was?  If not, is there an appropriate commit id?

Acked-by: Jay Vosburgh <[email-masked]>

	-J

>---
> drivers/net/bonding/bond_main.c | 2 ++
> 1 file changed, 2 insertions(+)
>
>diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>index 02fd782..931d9d9 100644
>--- a/drivers/net/bonding/bond_main.c
>+++ b/drivers/net/bonding/bond_main.c
>@@ -1126,6 +1126,8 @@ 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 |
>+				    NETIF_F_HW_VLAN_CTAG_TX |
>+				    NETIF_F_HW_VLAN_STAG_TX |
> 				    NETIF_F_GSO_UDP_L4;
> 	bond_dev->mpls_features = mpls_features;
> 	bond_dev->gso_max_segs = gso_max_segs;
>-- 
>2.7.4

---
	-Jay Vosburgh, [email-masked]