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: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230119221536.3349901-10-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index dfc7d87..70f5060 100644 (file)
--- 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 @@ xdp_drop:
        return NULL;
 err_xdp:
        rcu_read_unlock();
-       xdp_return_buff(&xdp);
+       xdp_return_buff(xdp);
 xdp_xmit:
        return NULL;
 }