Re: [PATCH net-next v2 5/6] vxlan: Add tx-vlan offload support.

[Pravin Shelar <pshelar@nicira.com>]

On Tue, Jul 23, 2013 at 12:27 PM, Ben Hutchings
<bhutchings@solarflare.com> wrote:
> On Tue, 2013-07-23 at 11:22 -0700, Pravin B Shelar wrote:
>> Following patch allows transmit side vlan offload for vxlan
>> devices.
>>
>> Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
>> ---
>>  drivers/net/vxlan.c |   15 ++++++++++++++-
>>  1 files changed, 14 insertions(+), 1 deletions(-)
>>
>> diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
>> index 1ca7ca3..f76c09c 100644
>> --- a/drivers/net/vxlan.c
>> +++ b/drivers/net/vxlan.c
>> @@ -27,6 +27,7 @@
>>  #include <linux/igmp.h>
>>  #include <linux/etherdevice.h>
>>  #include <linux/if_ether.h>
>> +#include <linux/if_vlan.h>
>>  #include <linux/hash.h>
>>  #include <linux/ethtool.h>
>>  #include <net/arp.h>
>> @@ -1076,13 +1077,23 @@ int vxlan_xmit_skb(struct net *net, struct vxlan_handler *vh,
>>       }
>>
>>       min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
>> -                     + VXLAN_HLEN + sizeof(struct iphdr);
>> +                     + VXLAN_HLEN + sizeof(struct iphdr)
>> +                     + (vlan_tx_tag_present(skb) ? VLAN_HLEN : 0);
>>
>>       /* Need space for new headers (invalidates iph ptr) */
>>       err = skb_cow_head(skb, min_headroom);
>>       if (unlikely(err))
>>               return err;
>>
>> +     if (vlan_tx_tag_present(skb)) {
>> +             if (unlikely(!__vlan_put_tag(skb,
>> +                                          skb->vlan_proto,
>> +                                          vlan_tx_tag_get(skb))))
>> +                     return -ENOMEM;
>
> This can't fail since we already did skb_cow_head().  So a WARN_ON()
> might be appropriate.
>
ok, I will add WARN_ON().

>> +             skb->vlan_tci = 0;
>> +     }
>> +
>>       vxh = (struct vxlanhdr *) __skb_push(skb, sizeof(*vxh));
>>       vxh->vx_flags = htonl(VXLAN_FLAGS);
>>       vxh->vx_vni = vni;
>> @@ -1486,6 +1497,8 @@ static void vxlan_setup(struct net_device *dev)
>>       dev->features   |= NETIF_F_RXCSUM;
>>       dev->features   |= NETIF_F_GSO_SOFTWARE;
>>
>> +     dev->vlan_features = dev->features;
>> +     dev->features |= NETIF_F_HW_VLAN_CTAG_TX;
>
> You can also add NETIF_F_HW_VLAN_STAG_TX.
ok.

>
>>       dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_RXCSUM;
>>       dev->hw_features |= NETIF_F_GSO_SOFTWARE;
>
> Should the VLAN TX features also be included in dev->hw_features?  (I'm
> not sure why you'd want to turn them off, but they are usually made
> optional.)
>
right, I forgot to update hw_features.


> Ben.
>
>>       dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
>
> --
> Ben Hutchings, Staff Engineer, Solarflare
> Not speaking for my employer; that's the marketing department's job.
> They asked us to note that Solarflare product names are trademarked.
>