From 04ffcb255f22a2a988ce7393e6e72f6eb3fcb7aa Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Tue, 14 Oct 2014 15:19:06 -0700 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- drivers/net/macvtap.c | 2 +- drivers/net/xen-netfront.c | 2 +- include/linux/netdevice.h | 12 +++++++++++- net/core/dev.c | 2 +- 4 files changed, 14 insertions(+), 4 deletions(-) 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 @@ static rx_handler_result_t macvtap_handle_frame(struct sk_buff **pskb) */ 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 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) 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 @@ typedef u16 (*select_queue_fallback_t)(struct net_device *dev, * 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_ops { 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 @@ static inline bool skb_gso_ok(struct sk_buff *skb, netdev_features_t features) (!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 @@ static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device 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); -- 2.7.4