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[NET]: Merge TSO/UFO fields in sk_buff

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Having separate fields in sk_buff for TSO/UFO (tso_size/ufo_size) is not
going to scale if we add any more segmentation methods (e.g., DCCP).  So
let's merge them.

They were used to tell the protocol of a packet.  This function has been
subsumed by the new gso_type field.  This is essentially a set of netdev
feature bits (shifted by 16 bits) that are required to process a specific
skb.  As such it's easy to tell whether a given device can process a GSO
skb: you just have to and the gso_type field and the netdev's features
field.

I've made gso_type a conjunction.  The idea is that you have a base type
(e.g., SKB_GSO_TCPV4) that can be modified further to support new features.
For example, if we add a hardware TSO type that supports ECN, they would
declare NETIF_F_TSO | NETIF_F_TSO_ECN.  All TSO packets with CWR set would
have a gso_type of SKB_GSO_TCPV4 | SKB_GSO_TCPV4_ECN while all other TSO
packets would be SKB_GSO_TCPV4.  This means that only the CWR packets need
to be emulated in software.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Herbert Xu
2006-06-22 02:40:14 -07:00
committed by David S. Miller
parent d4828d85d1
commit 7967168cef
27 changed files with 120 additions and 90 deletions
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14
include/linux/netdevice.h
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@ -308,9 +308,12 @@ struct net_device
#define NETIF_F_HW_VLAN_RX 256 /* Receive VLAN hw acceleration */
#define NETIF_F_HW_VLAN_FILTER 512 /* Receive filtering on VLAN */
#define NETIF_F_VLAN_CHALLENGED 1024 /* Device cannot handle VLAN packets */
#define NETIF_F_TSO 2048 /* Can offload TCP/IP segmentation */
#define NETIF_F_LLTX 4096 /* LockLess TX */
#define NETIF_F_UFO 8192 /* Can offload UDP Large Send*/
/* Segmentation offload features */
#define NETIF_F_GSO_SHIFT 16
#define NETIF_F_TSO (SKB_GSO_TCPV4 << NETIF_F_GSO_SHIFT)
#define NETIF_F_UFO (SKB_GSO_UDPV4 << NETIF_F_GSO_SHIFT)
#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)
@ -979,6 +982,13 @@ extern void dev_seq_stop(struct seq_file *seq, void *v);
extern void linkwatch_run_queue(void);
static inline int netif_needs_gso(struct net_device *dev, struct sk_buff *skb)
{
int feature = skb_shinfo(skb)->gso_type << NETIF_F_GSO_SHIFT;
return skb_shinfo(skb)->gso_size &&
(dev->features & feature) != feature;
}
#endif /* __KERNEL__ */
#endif /* _LINUX_DEV_H */