On Mon, Dec 18, 2017 at 01:10:30PM +0200, Ilya Lesokhin wrote:
> Offloaded sockets rely on the netdev to transform the transmitted
> packets before sending them over the network.
> When a packet from an offloaded socket is looped back or
> rerouted to a different device we need to detect it and
> do the transformation in software
>
> Signed-off-by: Ilya Lesokhin <[email protected]>
> Signed-off-by: Boris Pismenny <[email protected]>
> ---
> include/net/sock.h | 17 +++++++++++++++++
> net/core/dev.c | 4 ++++
> 2 files changed, 21 insertions(+)
>
> diff --git a/include/net/sock.h b/include/net/sock.h
> index 9a9047268d37..5397307603ec 100644
> --- a/include/net/sock.h
> +++ b/include/net/sock.h
> @@ -479,6 +479,9 @@ struct sock {
> void (*sk_error_report)(struct sock *sk);
> int (*sk_backlog_rcv)(struct sock *sk,
> struct sk_buff *skb);
> + struct sk_buff* (*sk_offload_check)(struct sock *sk,
> + struct net_device *dev,
> + struct sk_buff *skb);
> void (*sk_destruct)(struct sock *sk);
> struct sock_reuseport __rcu *sk_reuseport_cb;
> struct rcu_head sk_rcu;
> @@ -2324,6 +2327,20 @@ static inline bool sk_fullsock(const struct sock *sk)
> return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
> }
>
> +/* Checks if this SKB belongs to an HW offloaded socket
> + * and whether any SW fallbacks are required based on dev.
> + */
> +static inline struct sk_buff *skb_offload_check(struct sk_buff *skb,
> + struct net_device *dev)
> +{
> + struct sock *sk = skb->sk;
> +
> + if (sk && sk_fullsock(sk) && sk->sk_offload_check)
Isn't this going to hurt the fast path, checking for sk fields here?
> + skb = sk->sk_offload_check(sk, dev, skb);
> +
> + return skb;
> +}
> +
> /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
> * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
> */
> diff --git a/net/core/dev.c b/net/core/dev.c
> index b0eee49a2489..6a78d9046674 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -3051,6 +3051,10 @@ static struct sk_buff *validate_xmit_skb(struct
> sk_buff *skb, struct net_device
> if (unlikely(!skb))
> goto out_null;
>
> + skb = skb_offload_check(skb, dev);
> + if (!skb)
> + goto out_null;
> +
> if (netif_needs_gso(skb, features)) {
> struct sk_buff *segs;
>
> --
> 2.15.0.317.g14c63a9
>
