[PATCH net-next] net: bridge: replace __vlan_hwaccel_put_tag with skb_vlan_push

[PATCH net-next] net: bridge: replace __vlan_hwaccel_put_tag with skb_vlan_push

[Kangmin Park]

br_handle_ingress_vlan_tunnel() is called in br_handle_frame() and
goto drop when br_handle_ingress_vlan_tunnel() return non-zero.

But, br_handle_ingress_vlan_tunnel() always return 0. So, the goto
routine is currently meaningless.

However, paired function br_handle_egress_vlan_tunnel() call
skb_vlan_pop(). So, change br_handle_ingress_vlan_tunnel() to call
skb_vlan_push() instead of __vlan_hwaccel_put_tag(). And return
the return value of skb_vlan_push().

Signed-off-by: Kangmin Park <l4stpr0gr4m@gmail.com>
---
 net/bridge/br_vlan_tunnel.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/net/bridge/br_vlan_tunnel.c b/net/bridge/br_vlan_tunnel.c
index 01017448ebde..7b5a33dc9d4d 100644
--- a/net/bridge/br_vlan_tunnel.c
+++ b/net/bridge/br_vlan_tunnel.c
@@ -179,9 +179,7 @@ int br_handle_ingress_vlan_tunnel(struct sk_buff *skb,
 
 	skb_dst_drop(skb);
 
-	__vlan_hwaccel_put_tag(skb, p->br->vlan_proto, vlan->vid);
-
-	return 0;
+	return skb_vlan_push(skb, p->br->vlan_proto, vlan->vid);
 }
 
 int br_handle_egress_vlan_tunnel(struct sk_buff *skb,
-- 
2.26.2

Re: [PATCH net-next] net: bridge: replace __vlan_hwaccel_put_tag with skb_vlan_push

[Nikolay Aleksandrov]

On 23/08/2021 09:19, Kangmin Park wrote:
> br_handle_ingress_vlan_tunnel() is called in br_handle_frame() and
> goto drop when br_handle_ingress_vlan_tunnel() return non-zero.
> 
> But, br_handle_ingress_vlan_tunnel() always return 0. So, the goto
> routine is currently meaningless.
> 
> However, paired function br_handle_egress_vlan_tunnel() call
> skb_vlan_pop(). So, change br_handle_ingress_vlan_tunnel() to call
> skb_vlan_push() instead of __vlan_hwaccel_put_tag(). And return
> the return value of skb_vlan_push().
> 
> Signed-off-by: Kangmin Park <l4stpr0gr4m@gmail.com>
> ---
>  net/bridge/br_vlan_tunnel.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/net/bridge/br_vlan_tunnel.c b/net/bridge/br_vlan_tunnel.c
> index 01017448ebde..7b5a33dc9d4d 100644
> --- a/net/bridge/br_vlan_tunnel.c
> +++ b/net/bridge/br_vlan_tunnel.c
> @@ -179,9 +179,7 @@ int br_handle_ingress_vlan_tunnel(struct sk_buff *skb,
>  
>  	skb_dst_drop(skb);
>  
> -	__vlan_hwaccel_put_tag(skb, p->br->vlan_proto, vlan->vid);
> -
> -	return 0;
> +	return skb_vlan_push(skb, p->br->vlan_proto, vlan->vid);
>  }
>  
>  int br_handle_egress_vlan_tunnel(struct sk_buff *skb,
> 

This changes behaviour though, I don't like changing code just for the sake of it.
Perhaps the author had a reason to use hwaccel_put_tag instead. Before we would
just put hwaccel tag, now if there already is hwaccel tag we'll push it inside
the skb and then push the new tag in hwaccel. In fact I think you can even trigger
the warning inside skb_vlan_push, so:

Nacked-by: Nikolay Aleksandrov <nikolay@nvidia.com>

Re: [PATCH net-next] net: bridge: replace __vlan_hwaccel_put_tag with skb_vlan_push

[Kangmin Park]

2021년 8월 23일 (월) 오후 6:00, Nikolay Aleksandrov <nikolay@nvidia.com>님이 작성:
>
> On 23/08/2021 09:19, Kangmin Park wrote:
>
> This changes behaviour though, I don't like changing code just for the sake of it.
> Perhaps the author had a reason to use hwaccel_put_tag instead. Before we would
> just put hwaccel tag, now if there already is hwaccel tag we'll push it inside
> the skb and then push the new tag in hwaccel. In fact I think you can even trigger
> the warning inside skb_vlan_push, so:
>
> Nacked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
>
>

Thanks for the review. I got it.
Then, how about cleanup by changing return type of
br_handle_ingress_vlan_tunnel()?
This function is only referenced in br_handle_frame(), and goto drop
when it return
non-zero. But, the ingress function always return 0, there is no
meaning for now.
If you think the cleanup is worth it, I'll send you a v2 patch.

Regards.

Re: [PATCH net-next] net: bridge: replace __vlan_hwaccel_put_tag with skb_vlan_push

[Nikolay Aleksandrov]

On 23/08/2021 12:12, Kangmin Park wrote:
> 2021년 8월 23일 (월) 오후 6:00, Nikolay Aleksandrov <nikolay@nvidia.com>님이 작성:
>>
>> On 23/08/2021 09:19, Kangmin Park wrote:
>>
>> This changes behaviour though, I don't like changing code just for the sake of it.
>> Perhaps the author had a reason to use hwaccel_put_tag instead. Before we would
>> just put hwaccel tag, now if there already is hwaccel tag we'll push it inside
>> the skb and then push the new tag in hwaccel. In fact I think you can even trigger
>> the warning inside skb_vlan_push, so:
>>
>> Nacked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
>>
>>
> 
> Thanks for the review. I got it.
> Then, how about cleanup by changing return type of
> br_handle_ingress_vlan_tunnel()?
> This function is only referenced in br_handle_frame(), and goto drop
> when it return
> non-zero. But, the ingress function always return 0, there is no
> meaning for now.
> If you think the cleanup is worth it, I'll send you a v2 patch.
> 
> Regards.
> 

Sure, I don't mind that cleanup.

Cheers,
 Nik