Re: [RFC bpf-next 2/7] net: introduce skb_net helper

[Willem de Bruijn <willemdebruijn.kernel@gmail.com>]

On Tue, Feb 5, 2019 at 12:57 PM Stanislav Fomichev <sdf@google.com> wrote:
>
> skb_net returns network namespace from the associated device or socket.
>
> This will be used in the next commit.
>
> Signed-off-by: Stanislav Fomichev <sdf@google.com>
> ---
>  include/linux/skbuff.h |  2 ++
>  net/core/skbuff.c      | 10 ++++++++++
>  2 files changed, 12 insertions(+)
>
> diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
> index ad883ab2762c..28723a86efdf 100644
> --- a/include/linux/skbuff.h
> +++ b/include/linux/skbuff.h
> @@ -4343,5 +4343,7 @@ static inline __wsum lco_csum(struct sk_buff *skb)
>         return csum_partial(l4_hdr, csum_start - l4_hdr, partial);
>  }
>
> +struct net *skb_net(const struct sk_buff *skb);
> +
>  #endif /* __KERNEL__ */
>  #endif /* _LINUX_SKBUFF_H */
> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> index 23c9cf100bd4..016db13fa2b6 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -5585,6 +5585,16 @@ void skb_condense(struct sk_buff *skb)
>         skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
>  }
>
> +struct net *skb_net(const struct sk_buff *skb)
> +{
> +       if (skb->dev)
> +               return dev_net(skb->dev);
> +       else if (skb->sk)
> +               return sock_net(skb->sk);
> +       return NULL;
> +}
> +EXPORT_SYMBOL(skb_net);

If this needs a helper it is probably better static inline in the header.