commit 5142239a22219921a7863cf00c9ab853c00689d8 Author: Lorenzo Bianconi Date: Fri Mar 11 10:14:18 2022 +0100 net: veth: Account total xdp_frame len running ndo_xdp_xmit Even if this is a theoretical issue since it is not possible to perform XDP_REDIRECT on a non-linear xdp_frame, veth driver does not account paged area in ndo_xdp_xmit function pointer. Introduce xdp_get_frame_len utility routine to get the xdp_frame full length and account total frame size running XDP_REDIRECT of a non-linear xdp frame into a veth device. Signed-off-by: Lorenzo Bianconi Signed-off-by: Daniel Borkmann Acked-by: Toke Hoiland-Jorgensen Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/54f9fd3bb65d190daf2c0bbae2f852ff16cfbaa0.1646989407.git.lorenzo@kernel.org --- a/drivers/net/veth.c +++ b/drivers/net/veth.c @@ -501,7 +501,7 @@ static int veth_xdp_xmit(struct net_devi struct xdp_frame *frame = frames[i]; void *ptr = veth_xdp_to_ptr(frame); - if (unlikely(frame->len > max_len || + if (unlikely(xdp_get_frame_len(frame) > max_len || __ptr_ring_produce(&rq->xdp_ring, ptr))) break; nxmit++; @@ -862,7 +862,7 @@ static int veth_xdp_rcv(struct veth_rq * /* ndo_xdp_xmit */ struct xdp_frame *frame = veth_ptr_to_xdp(ptr); - stats->xdp_bytes += frame->len; + stats->xdp_bytes += xdp_get_frame_len(frame); frame = veth_xdp_rcv_one(rq, frame, bq, stats); if (frame) { /* XDP_PASS */ --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -295,6 +295,20 @@ out: __xdp_release_frame(xdpf->data, mem); } +static __always_inline unsigned int xdp_get_frame_len(struct xdp_frame *xdpf) +{ + struct skb_shared_info *sinfo; + unsigned int len = xdpf->len; + + if (likely(!xdp_frame_has_frags(xdpf))) + goto out; + + sinfo = xdp_get_shared_info_from_frame(xdpf); + len += sinfo->xdp_frags_size; +out: + return len; +} + int xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq, struct net_device *dev, u32 queue_index, unsigned int napi_id); void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq);