[PATCH net-next] net: ethtool: Fix set RXNFC call on drivers with no RXFH support

[Gal Pressman <gal@nvidia.com>]

Some interfaces support get/set_rxnfc but not get/set_rxfh (mlx5 IPoIB
for example).
Instead of failing the RXNFC command, do the symmetric xor sanity check
for interfaces that support get_rxfh only.

Fixes: dcd8dbf9e734 ("net: ethtool: get rid of get/set_rxfh_context functions")
Cc: Ahmed Zaki <ahmed.zaki@intel.com>
Signed-off-by: Gal Pressman <gal@nvidia.com>
---
 net/ethtool/ioctl.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 86d47425038b..42d02cf3a4b3 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -978,27 +978,29 @@ static noinline_for_stack int ethtool_set_rxnfc(struct net_device *dev,
 	size_t info_size = sizeof(info);
 	int rc;
 
-	if (!ops->set_rxnfc || !ops->get_rxfh)
+	if (!ops->set_rxnfc)
 		return -EOPNOTSUPP;
 
 	rc = ethtool_rxnfc_copy_struct(cmd, &info, &info_size, useraddr);
 	if (rc)
 		return rc;
 
-	rc = ops->get_rxfh(dev, &rxfh);
-	if (rc)
-		return rc;
-
 	/* Sanity check: if symmetric-xor is set, then:
 	 * 1 - no other fields besides IP src/dst and/or L4 src/dst
 	 * 2 - If src is set, dst must also be set
 	 */
-	if ((rxfh.input_xfrm & RXH_XFRM_SYM_XOR) &&
-	    ((info.data & ~(RXH_IP_SRC | RXH_IP_DST |
-			    RXH_L4_B_0_1 | RXH_L4_B_2_3)) ||
-	     (!!(info.data & RXH_IP_SRC) ^ !!(info.data & RXH_IP_DST)) ||
-	     (!!(info.data & RXH_L4_B_0_1) ^ !!(info.data & RXH_L4_B_2_3))))
-		return -EINVAL;
+	if (ops->get_rxfh) {
+		rc = ops->get_rxfh(dev, &rxfh);
+		if (rc)
+			return rc;
+
+		if ((rxfh.input_xfrm & RXH_XFRM_SYM_XOR) &&
+		    ((info.data & ~(RXH_IP_SRC | RXH_IP_DST |
+				    RXH_L4_B_0_1 | RXH_L4_B_2_3)) ||
+		     (!!(info.data & RXH_IP_SRC) ^ !!(info.data & RXH_IP_DST)) ||
+		     (!!(info.data & RXH_L4_B_0_1) ^ !!(info.data & RXH_L4_B_2_3))))
+			return -EINVAL;
+	}
 
 	rc = ops->set_rxnfc(dev, &info);
 	if (rc)
-- 
2.40.1