On Thu, Sep 06, 2018 at 12:05:16PM +0800, Jason Wang wrote:
> This patch introduces a new sock flag - SOCK_XDP. This will be used
> for notifying the upper layer that XDP program is attached on the
> lower socket, and requires for extra headroom.
>
> TUN will be the first user.
>
> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
In fact vhost is the 1st user, right? So this can be
pushed out to become patch 10/11.
> ---
> drivers/net/tun.c | 19 +++++++++++++++++++
> include/net/sock.h | 1 +
> 2 files changed, 20 insertions(+)
>
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index ebd07ad82431..2c548bd20393 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -869,6 +869,9 @@ static int tun_attach(struct tun_struct *tun, struct file *file,
> tun_napi_init(tun, tfile, napi);
> }
>
> + if (rtnl_dereference(tun->xdp_prog))
> + sock_set_flag(&tfile->sk, SOCK_XDP);
> +
> tun_set_real_num_queues(tun);
>
> /* device is allowed to go away first, so no need to hold extra
> @@ -1241,13 +1244,29 @@ static int tun_xdp_set(struct net_device *dev, struct bpf_prog *prog,
> struct netlink_ext_ack *extack)
> {
> struct tun_struct *tun = netdev_priv(dev);
> + struct tun_file *tfile;
> struct bpf_prog *old_prog;
> + int i;
>
> old_prog = rtnl_dereference(tun->xdp_prog);
> rcu_assign_pointer(tun->xdp_prog, prog);
> if (old_prog)
> bpf_prog_put(old_prog);
>
> + for (i = 0; i < tun->numqueues; i++) {
> + tfile = rtnl_dereference(tun->tfiles[i]);
> + if (prog)
> + sock_set_flag(&tfile->sk, SOCK_XDP);
> + else
> + sock_reset_flag(&tfile->sk, SOCK_XDP);
> + }
> + list_for_each_entry(tfile, &tun->disabled, next) {
> + if (prog)
> + sock_set_flag(&tfile->sk, SOCK_XDP);
> + else
> + sock_reset_flag(&tfile->sk, SOCK_XDP);
> + }
> +
> return 0;
> }
>
> diff --git a/include/net/sock.h b/include/net/sock.h
> index 433f45fc2d68..38cae35f6e16 100644
> --- a/include/net/sock.h
> +++ b/include/net/sock.h
> @@ -800,6 +800,7 @@ enum sock_flags {
> SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
> SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
> SOCK_TXTIME,
> + SOCK_XDP, /* XDP is attached */
> };
>
> #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
> --
> 2.17.1
