ethtool: Centralise validation of ETHTOOL_{G, S}RXFHINDIR parameters

Add a new ethtool operation (get_rxfh_indir_size) to get the
indirectional table size.  Use this to validate the user buffer size
before calling get_rxfh_indir or set_rxfh_indir.  Use get_rxnfc to get
the number of RX rings, and validate the contents of the new
indirection table before calling set_rxfh_indir.  Remove this
validation from drivers.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Acked-by: Dimitris Michailidis <dm@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 12 insertions, 23 deletions

diff --git a/drivers/net/ethernet/sfc/ethtool.c b/drivers/net/ethernet/sfc/ethtool.c
index f3cd96dfa398..1be51b2bfa42 100644
--- a/drivers/net/ethernet/sfc/ethtool.c
+++ b/drivers/net/ethernet/sfc/ethtool.c
@@ -956,40 +956,28 @@ static int efx_ethtool_set_rx_ntuple(struct net_device *net_dev,
         return rc < 0 ? rc : 0;
 }
 
-static int efx_ethtool_get_rxfh_indir(struct net_device *net_dev,
-                                      struct ethtool_rxfh_indir *indir)
+static u32 efx_ethtool_get_rxfh_indir_size(struct net_device *net_dev)
 {
         struct efx_nic *efx = netdev_priv(net_dev);
-        size_t copy_size =
-                min_t(size_t, indir->size, ARRAY_SIZE(efx->rx_indir_table));
 
-        if (efx_nic_rev(efx) < EFX_REV_FALCON_B0)
-                return -EOPNOTSUPP;
+        return (efx_nic_rev(efx) < EFX_REV_FALCON_B0 ?
+                0 : ARRAY_SIZE(efx->rx_indir_table));
+}
+
+static int efx_ethtool_get_rxfh_indir(struct net_device *net_dev, u32 *indir)
+{
+        struct efx_nic *efx = netdev_priv(net_dev);
 
-        indir->size = ARRAY_SIZE(efx->rx_indir_table);
-        memcpy(indir->ring_index, efx->rx_indir_table,
-               copy_size * sizeof(indir->ring_index[0]));
+        memcpy(indir, efx->rx_indir_table, sizeof(efx->rx_indir_table));
         return 0;
 }
 
 static int efx_ethtool_set_rxfh_indir(struct net_device *net_dev,
-                                      const struct ethtool_rxfh_indir *indir)
+                                      const u32 *indir)
 {
         struct efx_nic *efx = netdev_priv(net_dev);
-        size_t i;
-
-        if (efx_nic_rev(efx) < EFX_REV_FALCON_B0)
-                return -EOPNOTSUPP;
-
-        /* Validate size and indices */
-        if (indir->size != ARRAY_SIZE(efx->rx_indir_table))
-                return -EINVAL;
-        for (i = 0; i < ARRAY_SIZE(efx->rx_indir_table); i++)
-                if (indir->ring_index[i] >= efx->n_rx_channels)
-                        return -EINVAL;
 
-        memcpy(efx->rx_indir_table, indir->ring_index,
-               sizeof(efx->rx_indir_table));
+        memcpy(efx->rx_indir_table, indir, sizeof(efx->rx_indir_table));
         efx_nic_push_rx_indir_table(efx);
         return 0;
 }
@@ -1020,6 +1008,7 @@ const struct ethtool_ops efx_ethtool_ops = {
         .reset                  = efx_ethtool_reset,
         .get_rxnfc              = efx_ethtool_get_rxnfc,
         .set_rx_ntuple          = efx_ethtool_set_rx_ntuple,
+        .get_rxfh_indir_size    = efx_ethtool_get_rxfh_indir_size,
         .get_rxfh_indir         = efx_ethtool_get_rxfh_indir,
         .set_rxfh_indir         = efx_ethtool_set_rxfh_indir,
 };