vlan: more careful checksum features handling

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>
This commit is contained in:
Michal Kubeček 2014-05-20 08:29:25 +02:00 committed by David S. Miller
parent 98a6eeb8f5
commit da08143b85
2 changed files with 16 additions and 2 deletions

View File

@ -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)
{

View File

@ -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;