net: Add ndo_gso_check
Add ndo_gso_check which a device can define to indicate whether is
is capable of doing GSO on a packet. This funciton would be called from
the stack to determine whether software GSO is needed to be done. A
driver should populate this function if it advertises GSO types for
which there are combinations that it wouldn't be able to handle. For
instance a device that performs UDP tunneling might only implement
support for transparent Ethernet bridging type of inner packets
or might have limitations on lengths of inner headers.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 0c6adaa..65e2892 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -298,7 +298,7 @@
*/
if (q->flags & IFF_VNET_HDR)
features |= vlan->tap_features;
- if (netif_needs_gso(skb, features)) {
+ if (netif_needs_gso(dev, skb, features)) {
struct sk_buff *segs = __skb_gso_segment(skb, features, false);
if (IS_ERR(segs))
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index ca82f54..3c0b375 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -638,7 +638,7 @@
if (unlikely(!netif_carrier_ok(dev) ||
(slots > 1 && !xennet_can_sg(dev)) ||
- netif_needs_gso(skb, netif_skb_features(skb)))) {
+ netif_needs_gso(dev, skb, netif_skb_features(skb)))) {
spin_unlock_irqrestore(&queue->tx_lock, flags);
goto drop;
}
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 838407a..74fd5d3 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -998,6 +998,12 @@
* Callback to use for xmit over the accelerated station. This
* is used in place of ndo_start_xmit on accelerated net
* devices.
+ * bool (*ndo_gso_check) (struct sk_buff *skb,
+ * struct net_device *dev);
+ * Called by core transmit path to determine if device is capable of
+ * performing GSO on a packet. The device returns true if it is
+ * able to GSO the packet, false otherwise. If the return value is
+ * false the stack will do software GSO.
*/
struct net_device_ops {
int (*ndo_init)(struct net_device *dev);
@@ -1147,6 +1153,8 @@
struct net_device *dev,
void *priv);
int (*ndo_get_lock_subclass)(struct net_device *dev);
+ bool (*ndo_gso_check) (struct sk_buff *skb,
+ struct net_device *dev);
};
/**
@@ -3572,10 +3580,12 @@
(!skb_has_frag_list(skb) || (features & NETIF_F_FRAGLIST));
}
-static inline bool netif_needs_gso(struct sk_buff *skb,
+static inline bool netif_needs_gso(struct net_device *dev, struct sk_buff *skb,
netdev_features_t features)
{
return skb_is_gso(skb) && (!skb_gso_ok(skb, features) ||
+ (dev->netdev_ops->ndo_gso_check &&
+ !dev->netdev_ops->ndo_gso_check(skb, dev)) ||
unlikely((skb->ip_summed != CHECKSUM_PARTIAL) &&
(skb->ip_summed != CHECKSUM_UNNECESSARY)));
}
diff --git a/net/core/dev.c b/net/core/dev.c
index 4699dcf..9f77a78 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2675,7 +2675,7 @@
if (skb->encapsulation)
features &= dev->hw_enc_features;
- if (netif_needs_gso(skb, features)) {
+ if (netif_needs_gso(dev, skb, features)) {
struct sk_buff *segs;
segs = skb_gso_segment(skb, features);
