[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>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index b79d6e8d3045..43fef7de8cb9 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -74,7 +74,7 @@ static void emulate_large_send_offload(struct sk_buff *skb)
         struct iphdr *iph = skb->nh.iph;
         struct tcphdr *th = (struct tcphdr*)(skb->nh.raw + (iph->ihl * 4));
         unsigned int doffset = (iph->ihl + th->doff) * 4;
-        unsigned int mtu = skb_shinfo(skb)->tso_size + doffset;
+        unsigned int mtu = skb_shinfo(skb)->gso_size + doffset;
         unsigned int offset = 0;
         u32 seq = ntohl(th->seq);
         u16 id  = ntohs(iph->id);
@@ -139,7 +139,7 @@ static int loopback_xmit(struct sk_buff *skb, struct net_device *dev)
 #endif
 
 #ifdef LOOPBACK_TSO
-        if (skb_shinfo(skb)->tso_size) {
+        if (skb_shinfo(skb)->gso_size) {
                 BUG_ON(skb->protocol != htons(ETH_P_IP));
                 BUG_ON(skb->nh.iph->protocol != IPPROTO_TCP);