vlan: more careful checksum features handling (da08143b) · Commits · 戴 / test

When combining real_dev's features and vlan_features, simple bitwise AND is used. This doesn't work well for checksum offloading features as if one set has NETIF_F_HW_CSUM and the other NETIF_F_IP_CSUM and/or NETIF_F_IPV6_CSUM, we end up with no checksum offloading. However, from the logical point of view (how can_checksum_protocol() works), NETIF_F_HW_CSUM contains the functionality of NETIF_F_IP_CSUM and NETIF_F_IPV6_CSUM so that the result should be IP/IPV6. Add helper function netdev_intersect_features() implementing this logic and use it in vlan_dev_fix_features(). Signed-off-by:

Michal Kubecek <mkubecek@suse.cz> Signed-off-by:

David S. Miller <davem@davemloft.net>

include/linux/netdevice.h

+14 −0

Original line number	Diff line number	Diff line
		@@ -3153,6 +3153,20 @@ const char netdev_drivername(const struct net_device dev);

		void linkwatch_run_queue(void);

		static inline netdev_features_t netdev_intersect_features(netdev_features_t f1,
		netdev_features_t f2)
		{
		if (f1 & NETIF_F_GEN_CSUM)
		f1 \|= (NETIF_F_ALL_CSUM & ~NETIF_F_GEN_CSUM);
		if (f2 & NETIF_F_GEN_CSUM)
		f2 \|= (NETIF_F_ALL_CSUM & ~NETIF_F_GEN_CSUM);
		f1 &= f2;
		if (f1 & NETIF_F_GEN_CSUM)
		f1 &= ~(NETIF_F_ALL_CSUM & ~NETIF_F_GEN_CSUM);

		return f1;
		}

		static inline netdev_features_t netdev_get_wanted_features(
		struct net_device *dev)
		{

net/8021q/vlan_dev.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -678,9 +678,9 @@ static netdev_features_t vlan_dev_fix_features(struct net_device *dev,
		struct net_device *real_dev = vlan_dev_priv(dev)->real_dev;
		netdev_features_t old_features = features;

		features &= real_dev->vlan_features;
		features = netdev_intersect_features(features, real_dev->vlan_features);
		features \|= NETIF_F_RXCSUM;
		features &= real_dev->features;
		features = netdev_intersect_features(features, real_dev->features);

		features \|= old_features & NETIF_F_SOFT_FEATURES;
		features \|= NETIF_F_LLTX;

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