[PATCH bpf-next v4 2/6] net: veth: Add xmo_rx_checksum callback to veth driver

[Vladimir Vdovin <deliran@verdict.gg>]

From: Lorenzo Bianconi <lorenzo@kernel.org>

Implement xmo_rx_checksum callback in veth driver to report RX checksum
result to the eBPF program bounded to the veth device.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Vladimir Vdovin <deliran@verdict.gg>
---
 drivers/net/veth.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 1c5142149175..498d894d043d 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -1700,6 +1700,37 @@ static int veth_xdp_rx_vlan_tag(const struct xdp_md *ctx, __be16 *vlan_proto,
 	return err;
 }
 
+static int veth_xdp_rx_checksum(const struct xdp_md *ctx,
+				enum xdp_checksum *ip_summed,
+				u32 *cksum, u8 *cksum_level)
+{
+	const struct veth_xdp_buff *_ctx = (void *)ctx;
+	const struct sk_buff *skb = _ctx->skb;
+
+	if (!skb)
+		return -ENODATA;
+
+	switch (skb->ip_summed) {
+	case CHECKSUM_COMPLETE:
+		*ip_summed = XDP_CHECKSUM_COMPLETE;
+		*cksum = skb->csum;
+		*cksum_level = 0;
+		break;
+	case CHECKSUM_UNNECESSARY:
+		*ip_summed = XDP_CHECKSUM_UNNECESSARY;
+		*cksum_level = skb->csum_level;
+		*cksum = 0;
+		break;
+	default:
+		*ip_summed = XDP_CHECKSUM_NONE;
+		*cksum_level = 0;
+		*cksum = 0;
+		break;
+	}
+
+	return 0;
+}
+
 static const struct net_device_ops veth_netdev_ops = {
 	.ndo_init            = veth_dev_init,
 	.ndo_open            = veth_open,
@@ -1725,6 +1756,7 @@ static const struct xdp_metadata_ops veth_xdp_metadata_ops = {
 	.xmo_rx_timestamp		= veth_xdp_rx_timestamp,
 	.xmo_rx_hash			= veth_xdp_rx_hash,
 	.xmo_rx_vlan_tag		= veth_xdp_rx_vlan_tag,
+	.xmo_rx_checksum		= veth_xdp_rx_checksum,
 };
 
 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
-- 
2.47.0