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| author | Vlad Yasevich <vyasevich@gmail.com> | 2017-05-23 13:38:41 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-05-24 16:27:14 -0400 |
| commit | 35d2f80b07bbe03fb358afb0bdeff7437a7d67ff (patch) | |
| tree | bc2dc13dc4416dae8b0a57460f5d13aa65e6ffec | |
| parent | f2899788353c13891412b273fdff5f02d49aa40f (diff) | |
| download | linux-35d2f80b07bbe03fb358afb0bdeff7437a7d67ff.tar.gz linux-35d2f80b07bbe03fb358afb0bdeff7437a7d67ff.tar.bz2 linux-35d2f80b07bbe03fb358afb0bdeff7437a7d67ff.zip | |
vlan: Fix tcp checksum offloads in Q-in-Q vlans
It appears that TCP checksum offloading has been broken for
Q-in-Q vlans. The behavior was execerbated by the
series
commit afb0bc972b52 ("Merge branch 'stacked_vlan_tso'")
that that enabled accleleration features on stacked vlans.
However, event without that series, it is possible to trigger
this issue. It just requires a lot more specialized configuration.
The root cause is the interaction between how
netdev_intersect_features() works, the features actually set on
the vlan devices and HW having the ability to run checksum with
longer headers.
The issue starts when netdev_interesect_features() replaces
NETIF_F_HW_CSUM with a combination of NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM,
if the HW advertises IP|IPV6 specific checksums. This happens
for tagged and multi-tagged packets. However, HW that enables
IP|IPV6 checksum offloading doesn't gurantee that packets with
arbitrarily long headers can be checksummed.
This patch disables IP|IPV6 checksums on the packet for multi-tagged
packets.
CC: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
CC: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>
Acked-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/linux/if_vlan.h | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h index 8d5fcd6284ce..283dc2f5364d 100644 --- a/include/linux/if_vlan.h +++ b/include/linux/if_vlan.h @@ -614,14 +614,16 @@ static inline bool skb_vlan_tagged_multi(const struct sk_buff *skb) static inline netdev_features_t vlan_features_check(const struct sk_buff *skb, netdev_features_t features) { - if (skb_vlan_tagged_multi(skb)) - features = netdev_intersect_features(features, - NETIF_F_SG | - NETIF_F_HIGHDMA | - NETIF_F_FRAGLIST | - NETIF_F_HW_CSUM | - NETIF_F_HW_VLAN_CTAG_TX | - NETIF_F_HW_VLAN_STAG_TX); + if (skb_vlan_tagged_multi(skb)) { + /* In the case of multi-tagged packets, use a direct mask + * instead of using netdev_interesect_features(), to make + * sure that only devices supporting NETIF_F_HW_CSUM will + * have checksum offloading support. + */ + features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_HW_CSUM | + NETIF_F_FRAGLIST | NETIF_F_HW_VLAN_CTAG_TX | + NETIF_F_HW_VLAN_STAG_TX; + } return features; } |