[RFC 3/6] i40e: use extack for bpf errors

[Stephen Hemminger]

From: Stephen Hemminger <step...@networkplumber.org>

If ndo_bpf fails fill in error string with reason.

Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
---
 drivers/net/ethernet/intel/i40e/i40e_main.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c 
b/drivers/net/ethernet/intel/i40e/i40e_main.c
index da62218eb70a..3de1f2590ca0 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -11831,7 +11831,8 @@ static netdev_features_t i40e_features_check(struct 
sk_buff *skb,
  * @prog: XDP program
  **/
 static int i40e_xdp_setup(struct i40e_vsi *vsi,
-                         struct bpf_prog *prog)
+                         struct bpf_prog *prog,
+                         struct netlink_ext_ack *extack)
 {
        int frame_size = vsi->netdev->mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN;
        struct i40e_pf *pf = vsi->back;
@@ -11840,8 +11841,10 @@ static int i40e_xdp_setup(struct i40e_vsi *vsi,
        int i;
 
        /* Don't allow frames that span over multiple buffers */
-       if (frame_size > vsi->rx_buf_len)
+       if (frame_size > vsi->rx_buf_len) {
+               NL_SET_ERR_MSG(extack, "XDP does not support multiple buffers");
                return -EINVAL;
+       }
 
        if (!i40e_enabled_xdp_vsi(vsi) && !prog)
                return 0;
@@ -12140,12 +12143,14 @@ static int i40e_xdp(struct net_device *dev,
        struct i40e_netdev_priv *np = netdev_priv(dev);
        struct i40e_vsi *vsi = np->vsi;
 
-       if (vsi->type != I40E_VSI_MAIN)
+       if (vsi->type != I40E_VSI_MAIN) {
+               NL_SET_ERR_MSG(xdp->extack, "XDP not allowed on VF");
                return -EINVAL;
+       }
 
        switch (xdp->command) {
        case XDP_SETUP_PROG:
-               return i40e_xdp_setup(vsi, xdp->prog);
+               return i40e_xdp_setup(vsi, xdp->prog, xdp->extack);
        case XDP_QUERY_PROG:
                xdp->prog_id = vsi->xdp_prog ? vsi->xdp_prog->aux->id : 0;
                return 0;
@@ -12153,6 +12158,7 @@ static int i40e_xdp(struct net_device *dev,
                return i40e_xsk_umem_setup(vsi, xdp->xsk.umem,
                                           xdp->xsk.queue_id);
        default:
+               NL_SET_ERR_MSG(xdp->extack, "Unknown XDP command");
                return -EINVAL;
        }
 }
-- 
2.17.1