ethtool: Disallow ETHTOOL_SRSSH with both indir table and hash key unchanged

This would be a no-op, so there is no reason to request it.

This also allows conversion of the current implementations of
ethtool_ops::{get,set}_rxfh_indir to ethtool_ops::{get,set}_rxfh
with no change other than their parameters.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

1 files changed, 4 insertions, 1 deletions

diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 7156fe5ca876..b8857348bdf3 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -802,11 +802,14 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
                 return -EFAULT;
 
         /* If either indir or hash key is valid, proceed further.
+         * It is not valid to request that both be unchanged.
          */
         if ((user_indir_size &&
              user_indir_size != ETH_RXFH_INDIR_NO_CHANGE &&
              user_indir_size != dev_indir_size) ||
-            (user_key_size && (user_key_size != dev_key_size)))
+            (user_key_size && (user_key_size != dev_key_size)) ||
+            (user_indir_size == ETH_RXFH_INDIR_NO_CHANGE &&
+             user_key_size == 0))
                 return -EINVAL;
 
         if (user_indir_size != ETH_RXFH_INDIR_NO_CHANGE)