[net-next PATCH 3/8] net: Fix netdev_fix_features so that TSO_MANGLEID is only available with TSO

[Alexander Duyck <aduyck@mirantis.com>]

This change makes it so that we will strip the TSO_MANGLEID bit if TSO is
not present.  This way we will also handle ECN correctly of TSO is not
present.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
---
 net/core/dev.c |    4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/core/dev.c b/net/core/dev.c
index d6d9f286c4e1..6a5ef49ed1ab 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6720,6 +6720,10 @@ static netdev_features_t netdev_fix_features(struct net_device *dev,
 		features &= ~NETIF_F_TSO6;
 	}
 
+	/* TSO with IPv4 ID mangling requires IPv4 TSO be enabled */
+	if ((features & NETIF_F_TSO_MANGLEID) && !(features & NETIF_F_TSO))
+		features &= ~NETIF_F_TSO_MANGLEID;
+
 	/* TSO ECN requires that TSO is present as well. */
 	if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
 		features &= ~NETIF_F_TSO_ECN;