Packets from TAP devices with USO offload converts
to GSO_UDP_L4 & GSO_DODGY sk buffers.
Added changes allow skipping segmentation for DODGY/ROBUST packets.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
---
 net/ipv4/udp_offload.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index 6d1a4bec2614..8e002419b4d5 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -387,7 +387,7 @@ static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
 	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
 		goto out;
 
-	if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
+	if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && !skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST))
 		return __udp_gso_segment(skb, features, false);
 
 	mss = skb_shinfo(skb)->gso_size;
-- 
2.37.2

On 9/7/22 6:50 AM, Andrew Melnychenko wrote:
> diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
> index 6d1a4bec2614..8e002419b4d5 100644
> --- a/net/ipv4/udp_offload.c
> +++ b/net/ipv4/udp_offload.c
> @@ -387,7 +387,7 @@ static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
>  	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
>  		goto out;
>  
> -	if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
> +	if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && !skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST))

that line needs to be wrapped.

>  		return __udp_gso_segment(skb, features, false);
>  
>  	mss = skb_shinfo(skb)->gso_size;

Hi all,

On Thu, Sep 8, 2022 at 3:40 AM David Ahern <dsahern@kernel.org> wrote:
>
> On 9/7/22 6:50 AM, Andrew Melnychenko wrote:
> > diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
> > index 6d1a4bec2614..8e002419b4d5 100644
> > --- a/net/ipv4/udp_offload.c
> > +++ b/net/ipv4/udp_offload.c
> > @@ -387,7 +387,7 @@ static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
> >       if (!pskb_may_pull(skb, sizeof(struct udphdr)))
> >               goto out;
> >
> > -     if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
> > +     if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && !skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST))
>
> that line needs to be wrapped.

Ok, I'll wrap it.

>
> >               return __udp_gso_segment(skb, features, false);
> >
> >       mss = skb_shinfo(skb)->gso_size;
>