[PATCH bpf-next v2 3/8] veth: Introduce veth_xdp_buff wrapper for xdp_buff

Stanislav Fomichev
2022-11-21T18:26:06Z

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: Stanislav Fomichev <sdf@google.com>
---
drivers/net/veth.c | 56 +++++++++++++++++++++++++---------------------
1 file changed, 31 insertions(+), 25 deletions(-)

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 2a4592780141..bbabc592d431 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -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;
}
--
2.38.1.584.g0f3c55d4c2-goog