[NET]: Added GSO toggle

This patch adds a generic segmentation offload toggle that can be turned
on/off for each net device.  For now it only supports in TCPv4.

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

2 files changed, 40 insertions, 6 deletions

diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index fdec773f5b52..07956ecf545e 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -376,15 +376,20 @@ void br_features_recompute(struct net_bridge *br)
         features = br->feature_mask & ~NETIF_F_ALL_CSUM;
 
         list_for_each_entry(p, &br->port_list, list) {
-                if (checksum & NETIF_F_NO_CSUM &&
-                    !(p->dev->features & NETIF_F_NO_CSUM))
+                unsigned long feature = p->dev->features;
+
+                if (checksum & NETIF_F_NO_CSUM && !(feature & NETIF_F_NO_CSUM))
                         checksum ^= NETIF_F_NO_CSUM | NETIF_F_HW_CSUM;
-                if (checksum & NETIF_F_HW_CSUM &&
-                    !(p->dev->features & NETIF_F_HW_CSUM))
+                if (checksum & NETIF_F_HW_CSUM && !(feature & NETIF_F_HW_CSUM))
                         checksum ^= NETIF_F_HW_CSUM | NETIF_F_IP_CSUM;
-                if (!(p->dev->features & NETIF_F_IP_CSUM))
+                if (!(feature & NETIF_F_IP_CSUM))
                         checksum = 0;
-                features &= p->dev->features;
+
+                if (feature & NETIF_F_GSO)
+                        feature |= NETIF_F_TSO;
+                feature |= NETIF_F_GSO;
+
+                features &= feature;
         }
 
         br->dev->features = features | checksum | NETIF_F_LLTX;
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 33ce7ed6afc6..27ce1683caf5 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -614,6 +614,29 @@ static int ethtool_set_ufo(struct net_device *dev, char __user *useraddr)
         return dev->ethtool_ops->set_ufo(dev, edata.data);
 }
 
+static int ethtool_get_gso(struct net_device *dev, char __user *useraddr)
+{
+        struct ethtool_value edata = { ETHTOOL_GGSO };
+
+        edata.data = dev->features & NETIF_F_GSO;
+        if (copy_to_user(useraddr, &edata, sizeof(edata)))
+                 return -EFAULT;
+        return 0;
+}
+
+static int ethtool_set_gso(struct net_device *dev, char __user *useraddr)
+{
+        struct ethtool_value edata;
+
+        if (copy_from_user(&edata, useraddr, sizeof(edata)))
+                return -EFAULT;
+        if (edata.data)
+                dev->features |= NETIF_F_GSO;
+        else
+                dev->features &= ~NETIF_F_GSO;
+        return 0;
+}
+
 static int ethtool_self_test(struct net_device *dev, char __user *useraddr)
 {
         struct ethtool_test test;
@@ -905,6 +928,12 @@ int dev_ethtool(struct ifreq *ifr)
         case ETHTOOL_SUFO:
                 rc = ethtool_set_ufo(dev, useraddr);
                 break;
+        case ETHTOOL_GGSO:
+                rc = ethtool_get_gso(dev, useraddr);
+                break;
+        case ETHTOOL_SGSO:
+                rc = ethtool_set_gso(dev, useraddr);
+                break;
         default:
                 rc =  -EOPNOTSUPP;
         }