[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/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 8538aac..7624fd1 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -210,8 +210,7 @@
return dst_output(skb);
}
#endif
- if (skb->len > dst_mtu(skb->dst) &&
- !(skb_shinfo(skb)->ufo_size || skb_shinfo(skb)->tso_size))
+ if (skb->len > dst_mtu(skb->dst) && !skb_shinfo(skb)->gso_size)
return ip_fragment(skb, ip_finish_output2);
else
return ip_finish_output2(skb);
@@ -362,7 +361,7 @@
}
ip_select_ident_more(iph, &rt->u.dst, sk,
- (skb_shinfo(skb)->tso_segs ?: 1) - 1);
+ (skb_shinfo(skb)->gso_segs ?: 1) - 1);
/* Add an IP checksum. */
ip_send_check(iph);
@@ -744,7 +743,8 @@
(length - transhdrlen));
if (!err) {
/* specify the length of each IP datagram fragment*/
- skb_shinfo(skb)->ufo_size = (mtu - fragheaderlen);
+ skb_shinfo(skb)->gso_size = mtu - fragheaderlen;
+ skb_shinfo(skb)->gso_type = SKB_GSO_UDPV4;
__skb_queue_tail(&sk->sk_write_queue, skb);
return 0;
@@ -1087,14 +1087,16 @@
inet->cork.length += size;
if ((sk->sk_protocol == IPPROTO_UDP) &&
- (rt->u.dst.dev->features & NETIF_F_UFO))
- skb_shinfo(skb)->ufo_size = (mtu - fragheaderlen);
+ (rt->u.dst.dev->features & NETIF_F_UFO)) {
+ skb_shinfo(skb)->gso_size = mtu - fragheaderlen;
+ skb_shinfo(skb)->gso_type = SKB_GSO_UDPV4;
+ }
while (size > 0) {
int i;
- if (skb_shinfo(skb)->ufo_size)
+ if (skb_shinfo(skb)->gso_size)
len = size;
else {