veth: Support RX XDP metadata

The goal is to enable end-to-end testing of the metadata for AF_XDP.

Cc: John Fastabend <john.fastabend@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Anatoly Burakov <anatoly.burakov@intel.com>
Cc: Alexander Lobakin <alexandr.lobakin@intel.com>
Cc: Magnus Karlsson <magnus.karlsson@gmail.com>
Cc: Maryam Tahhan <mtahhan@redhat.com>
Cc: xdp-hints@xdp-project.net
Cc: netdev@vger.kernel.org
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230119221536.3349901-11-sdf@google.comSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

drivers/net/veth.c

@@ -118,6 +118,7 @@ static struct {
 
 struct veth_xdp_buff {
 	struct xdp_buff xdp;
+	struct sk_buff *skb;
 };
 
 static int veth_get_link_ksettings(struct net_device *dev,
@@ -602,6 +603,7 @@ static struct xdp_frame *veth_xdp_rcv_one(struct veth_rq *rq,
 
 		xdp_convert_frame_to_buff(frame, xdp);
 		xdp->rxq = &rq->xdp_rxq;
+		vxbuf.skb = NULL;
 
 		act = bpf_prog_run_xdp(xdp_prog, xdp);
 
@@ -823,6 +825,7 @@ static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
 	__skb_push(skb, skb->data - skb_mac_header(skb));
 	if (veth_convert_skb_to_xdp_buff(rq, xdp, &skb))
 		goto drop;
+	vxbuf.skb = skb;
 
 	orig_data = xdp->data;
 	orig_data_end = xdp->data_end;
@@ -1602,6 +1605,28 @@ static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
 	}
 }
 
+static int veth_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
+{
+	struct veth_xdp_buff *_ctx = (void *)ctx;
+
+	if (!_ctx->skb)
+		return -EOPNOTSUPP;
+
+	*timestamp = skb_hwtstamps(_ctx->skb)->hwtstamp;
+	return 0;
+}
+
+static int veth_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash)
+{
+	struct veth_xdp_buff *_ctx = (void *)ctx;
+
+	if (!_ctx->skb)
+		return -EOPNOTSUPP;
+
+	*hash = skb_get_hash(_ctx->skb);
+	return 0;
+}
+
 static const struct net_device_ops veth_netdev_ops = {
 	.ndo_init            = veth_dev_init,
 	.ndo_open            = veth_open,
@@ -1623,6 +1648,11 @@ static const struct net_device_ops veth_netdev_ops = {
 	.ndo_get_peer_dev	= veth_peer_dev,
 };
 
+static const struct xdp_metadata_ops veth_xdp_metadata_ops = {
+	.xmo_rx_timestamp		= veth_xdp_rx_timestamp,
+	.xmo_rx_hash			= veth_xdp_rx_hash,
+};
+
 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
 		       NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
 		       NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
@@ -1639,6 +1669,7 @@ static void veth_setup(struct net_device *dev)
 	dev->priv_flags |= IFF_PHONY_HEADROOM;
 
 	dev->netdev_ops = &veth_netdev_ops;
+	dev->xdp_metadata_ops = &veth_xdp_metadata_ops;
 	dev->ethtool_ops = &veth_ethtool_ops;
 	dev->features |= NETIF_F_LLTX;
 	dev->features |= VETH_FEATURES;