tun: Add XDP frame size

The tun driver have two code paths for running XDP (bpf_prog_run_xdp).
In both cases 'buflen' contains enough tailroom for skb_shared_info.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/bpf/158945343419.97035.9594485183958037621.stgit@firesoul

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 44889eb..c54f967 100644 (file)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1671,6 +1671,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
                xdp_set_data_meta_invalid(&xdp);
                xdp.data_end = xdp.data + len;
                xdp.rxq = &tfile->xdp_rxq;
+               xdp.frame_sz = buflen;
 
                act = bpf_prog_run_xdp(xdp_prog, &xdp);
                if (act == XDP_REDIRECT || act == XDP_TX) {
@@ -2411,6 +2412,7 @@ static int tun_xdp_one(struct tun_struct *tun,
                }
                xdp_set_data_meta_invalid(xdp);
                xdp->rxq = &tfile->xdp_rxq;
+               xdp->frame_sz = buflen;
 
                act = bpf_prog_run_xdp(xdp_prog, xdp);
                err = tun_xdp_act(tun, xdp_prog, xdp, act);