From: Jesper Dangaard Brouer <brouer@redhat.com>
Date: Thu, 14 May 2020 12:50:34 +0200
Subject: tun: Add XDP frame size
Patch-mainline: v5.8-rc1
Git-commit: fb3e6e9307973d2f70a173f1b33d1054fa2b691f
References: bsc#1176447

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
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/tun.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1671,6 +1671,7 @@ static struct sk_buff *tun_build_skb(str
 		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
 		}
 		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);