[NET]: Merge TSO/UFO fields in sk_buff
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>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index cead6be..fa56713 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -308,9 +308,12 @@
#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 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 */
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index f8c7eb7..97b0d2d 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -134,9 +134,10 @@
struct skb_shared_info {
atomic_t dataref;
unsigned short nr_frags;
- unsigned short tso_size;
- unsigned short tso_segs;
- unsigned short ufo_size;
+ unsigned short gso_size;
+ /* Warning: this field is not always filled in (UFO)! */
+ unsigned short gso_segs;
+ unsigned short gso_type;
unsigned int ip6_frag_id;
struct sk_buff *frag_list;
skb_frag_t frags[MAX_SKB_FRAGS];
@@ -168,6 +169,11 @@
SKB_FCLONE_CLONE,
};
+enum {
+ SKB_GSO_TCPV4 = 1 << 0,
+ SKB_GSO_UDPV4 = 1 << 1,
+};
+
/**
* struct sk_buff - socket buffer
* @next: Next buffer in list