Commit fefb695a authored by Stanislav Fomichev's avatar Stanislav Fomichev Committed by Martin KaFai Lau
Browse files

veth: Introduce veth_xdp_buff wrapper for xdp_buff 



No functional changes. Boilerplate to allow stuffing more data after xdp_buff.

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: default avatarStanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230119221536.3349901-10-sdf@google.com


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parent fd7c211d

drivers/net/veth.c

+31 −25
Original line number Diff line number Diff line
@@ -116,6 +116,10 @@ static struct { 
	{ "peer_ifindex" },

};



struct veth_xdp_buff {

	struct xdp_buff xdp;

};



static int veth_get_link_ksettings(struct net_device *dev,

				   struct ethtool_link_ksettings *cmd)

{
@@ -592,23 +596,24 @@ static struct xdp_frame *veth_xdp_rcv_one(struct veth_rq *rq, 
	rcu_read_lock();

	xdp_prog = rcu_dereference(rq->xdp_prog);

	if (likely(xdp_prog)) {

		struct xdp_buff xdp;

		struct veth_xdp_buff vxbuf;

		struct xdp_buff *xdp = &vxbuf.xdp;

		u32 act;



		xdp_convert_frame_to_buff(frame, &xdp);

		xdp.rxq = &rq->xdp_rxq;

		xdp_convert_frame_to_buff(frame, xdp);

		xdp->rxq = &rq->xdp_rxq;



		act = bpf_prog_run_xdp(xdp_prog, &xdp);

		act = bpf_prog_run_xdp(xdp_prog, xdp);



		switch (act) {

		case XDP_PASS:

			if (xdp_update_frame_from_buff(&xdp, frame))

			if (xdp_update_frame_from_buff(xdp, frame))

				goto err_xdp;

			break;

		case XDP_TX:

			orig_frame = *frame;

			xdp.rxq->mem = frame->mem;

			if (unlikely(veth_xdp_tx(rq, &xdp, bq) < 0)) {

			xdp->rxq->mem = frame->mem;

			if (unlikely(veth_xdp_tx(rq, xdp, bq) < 0)) {

				trace_xdp_exception(rq->dev, xdp_prog, act);

				frame = &orig_frame;

				stats->rx_drops++;
@@ -619,8 +624,8 @@ static struct xdp_frame *veth_xdp_rcv_one(struct veth_rq *rq, 
			goto xdp_xmit;

		case XDP_REDIRECT:

			orig_frame = *frame;

			xdp.rxq->mem = frame->mem;

			if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {

			xdp->rxq->mem = frame->mem;

			if (xdp_do_redirect(rq->dev, xdp, xdp_prog)) {

				frame = &orig_frame;

				stats->rx_drops++;

				goto err_xdp;
@@ -801,7 +806,8 @@ static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq, 
{

	void *orig_data, *orig_data_end;

	struct bpf_prog *xdp_prog;

	struct xdp_buff xdp;

	struct veth_xdp_buff vxbuf;

	struct xdp_buff *xdp = &vxbuf.xdp;

	u32 act, metalen;

	int off;
@@ -815,22 +821,22 @@ 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))

	if (veth_convert_skb_to_xdp_buff(rq, xdp, &skb))

		goto drop;



	orig_data = xdp.data;

	orig_data_end = xdp.data_end;

	orig_data = xdp->data;

	orig_data_end = xdp->data_end;



	act = bpf_prog_run_xdp(xdp_prog, &xdp);

	act = bpf_prog_run_xdp(xdp_prog, xdp);



	switch (act) {

	case XDP_PASS:

		break;

	case XDP_TX:

		veth_xdp_get(&xdp);

		veth_xdp_get(xdp);

		consume_skb(skb);

		xdp.rxq->mem = rq->xdp_mem;

		if (unlikely(veth_xdp_tx(rq, &xdp, bq) < 0)) {

		xdp->rxq->mem = rq->xdp_mem;

		if (unlikely(veth_xdp_tx(rq, xdp, bq) < 0)) {

			trace_xdp_exception(rq->dev, xdp_prog, act);

			stats->rx_drops++;

			goto err_xdp;
@@ -839,10 +845,10 @@ static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq, 
		rcu_read_unlock();

		goto xdp_xmit;

	case XDP_REDIRECT:

		veth_xdp_get(&xdp);

		veth_xdp_get(xdp);

		consume_skb(skb);

		xdp.rxq->mem = rq->xdp_mem;

		if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {

		xdp->rxq->mem = rq->xdp_mem;

		if (xdp_do_redirect(rq->dev, xdp, xdp_prog)) {

			stats->rx_drops++;

			goto err_xdp;

		}
@@ -862,7 +868,7 @@ static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq, 
	rcu_read_unlock();



	/* check if bpf_xdp_adjust_head was used */

	off = orig_data - xdp.data;

	off = orig_data - xdp->data;

	if (off > 0)

		__skb_push(skb, off);

	else if (off < 0)
@@ -871,21 +877,21 @@ static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq, 
	skb_reset_mac_header(skb);



	/* check if bpf_xdp_adjust_tail was used */

	off = xdp.data_end - orig_data_end;

	off = xdp->data_end - orig_data_end;

	if (off != 0)

		__skb_put(skb, off); /* positive on grow, negative on shrink */



	/* XDP frag metadata (e.g. nr_frags) are updated in eBPF helpers

	 * (e.g. bpf_xdp_adjust_tail), we need to update data_len here.

	 */

	if (xdp_buff_has_frags(&xdp))

	if (xdp_buff_has_frags(xdp))

		skb->data_len = skb_shinfo(skb)->xdp_frags_size;

	else

		skb->data_len = 0;



	skb->protocol = eth_type_trans(skb, rq->dev);



	metalen = xdp.data - xdp.data_meta;

	metalen = xdp->data - xdp->data_meta;

	if (metalen)

		skb_metadata_set(skb, metalen);

out:
@@ -898,7 +904,7 @@ static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq, 
	return NULL;

err_xdp:

	rcu_read_unlock();

	xdp_return_buff(&xdp);

	xdp_return_buff(xdp);

xdp_xmit:

	return NULL;

}