[BRIDGE]: Disable SG/GSO if TX checksum is off

When the bridge recomputes features, it does not maintain the
constraint that SG/GSO must be off if TX checksum is off.
This patch adds that constraint.

On a completely unrelated note, I've also added TSO6 and TSO_ECN
feature bits if GSO is enabled on the underlying device through
the new NETIF_F_GSO_SOFTWARE macro.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 9 insertions, 1 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index c0c2b46face1..50a4719512ed 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -320,6 +320,9 @@ struct net_device
 #define NETIF_F_TSO_ECN         (SKB_GSO_TCP_ECN << NETIF_F_GSO_SHIFT)
 #define NETIF_F_TSO6            (SKB_GSO_TCPV6 << NETIF_F_GSO_SHIFT)
 
+        /* List of features with software fallbacks. */
+#define NETIF_F_GSO_SOFTWARE    (NETIF_F_TSO | NETIF_F_TSO_ECN | NETIF_F_TSO6)
+
 #define NETIF_F_GEN_CSUM        (NETIF_F_NO_CSUM | NETIF_F_HW_CSUM)
 #define NETIF_F_ALL_CSUM        (NETIF_F_IP_CSUM | NETIF_F_GEN_CSUM)
 
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index f55ef682ef84..b1211d5342f6 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -386,12 +386,17 @@ void br_features_recompute(struct net_bridge *br)
                         checksum = 0;
 
                 if (feature & NETIF_F_GSO)
-                        feature |= NETIF_F_TSO;
+                        feature |= NETIF_F_GSO_SOFTWARE;
                 feature |= NETIF_F_GSO;
 
                 features &= feature;
         }
 
+        if (!(checksum & NETIF_F_ALL_CSUM))
+                features &= ~NETIF_F_SG;
+        if (!(features & NETIF_F_SG))
+                features &= ~NETIF_F_GSO_MASK;
+
         br->dev->features = features | checksum | NETIF_F_LLTX |
                             NETIF_F_GSO_ROBUST;
 }