[PATCH v3 bpf-next 1/2] xdp: introduce xdp_convert_frame_to_buff utility routine

[Lorenzo Bianconi]

Introduce xdp_convert_frame_to_buff utility routine to initialize xdp_buff
fields from xdp_frames ones. Rely on xdp_convert_frame_to_buff in veth xdp
code.

Suggested-by: Jesper Dangaard Brouer <bro...@redhat.com>
Acked-by: Jesper Dangaard Brouer <bro...@redhat.com>
Signed-off-by: Lorenzo Bianconi <lore...@kernel.org>
---
 drivers/net/veth.c |  6 +-----
 include/net/xdp.h  | 10 ++++++++++
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index b586d2fa5551..fb5c17361f64 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -575,11 +575,7 @@ static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
                struct xdp_buff xdp;
                u32 act;
 
-               xdp.data_hard_start = hard_start;
-               xdp.data = frame->data;
-               xdp.data_end = frame->data + frame->len;
-               xdp.data_meta = frame->data - frame->metasize;
-               xdp.frame_sz = frame->frame_sz;
+               xdp_convert_frame_to_buff(frame, &xdp);
                xdp.rxq = &rq->xdp_rxq;
 
                act = bpf_prog_run_xdp(xdp_prog, &xdp);
diff --git a/include/net/xdp.h b/include/net/xdp.h
index 90f11760bd12..96d4d4a9d27b 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -106,6 +106,16 @@ void xdp_warn(const char *msg, const char *func, const int 
line);
 
 struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp);
 
+static inline
+void xdp_convert_frame_to_buff(struct xdp_frame *frame, struct xdp_buff *xdp)
+{
+       xdp->data_hard_start = frame->data - frame->headroom - sizeof(*frame);
+       xdp->data = frame->data;
+       xdp->data_end = frame->data + frame->len;
+       xdp->data_meta = frame->data - frame->metasize;
+       xdp->frame_sz = frame->frame_sz;
+}
+
 /* Convert xdp_buff to xdp_frame */
 static inline
 struct xdp_frame *convert_to_xdp_frame(struct xdp_buff *xdp)
-- 
2.26.2