[NET] gso: Add skb_is_gso

This patch adds the wrapper function skb_is_gso which can be used instead
of directly testing skb_shinfo(skb)->gso_size.  This makes things a little
nicer and allows us to change the primary key for indicating whether an skb
is GSO (if we ever want to do that).

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index 8be9f21..6ccd32b 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -35,7 +35,7 @@
 int br_dev_queue_push_xmit(struct sk_buff *skb)
 {
 	/* drop mtu oversized packets except gso */
-	if (packet_length(skb) > skb->dev->mtu && !skb_shinfo(skb)->gso_size)
+	if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb))
 		kfree_skb(skb);
 	else {
 #ifdef CONFIG_BRIDGE_NETFILTER
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index 8298a51..cbc8a38 100644
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -761,7 +761,7 @@
 {
 	if (skb->protocol == htons(ETH_P_IP) &&
 	    skb->len > skb->dev->mtu &&
-	    !skb_shinfo(skb)->gso_size)
+	    !skb_is_gso(skb))
 		return ip_fragment(skb, br_dev_queue_push_xmit);
 	else
 		return br_dev_queue_push_xmit(skb);
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index ca0e714..7c9f9a6 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -209,7 +209,7 @@
 		return dst_output(skb);
 	}
 #endif
-	if (skb->len > dst_mtu(skb->dst) && !skb_shinfo(skb)->gso_size)
+	if (skb->len > dst_mtu(skb->dst) && !skb_is_gso(skb))
 		return ip_fragment(skb, ip_finish_output2);
 	else
 		return ip_finish_output2(skb);
@@ -1095,7 +1095,7 @@
 	while (size > 0) {
 		int i;
 
-		if (skb_shinfo(skb)->gso_size)
+		if (skb_is_gso(skb))
 			len = size;
 		else {
 
diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c
index 193363e..d16f863 100644
--- a/net/ipv4/xfrm4_output.c
+++ b/net/ipv4/xfrm4_output.c
@@ -134,7 +134,7 @@
 	}
 #endif
 
-	if (!skb_shinfo(skb)->gso_size)
+	if (!skb_is_gso(skb))
 		return xfrm4_output_finish2(skb);
 
 	skb->protocol = htons(ETH_P_IP);
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 2c5b445..3bc74ce 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -147,7 +147,7 @@
 
 int ip6_output(struct sk_buff *skb)
 {
-	if ((skb->len > dst_mtu(skb->dst) && !skb_shinfo(skb)->gso_size) ||
+	if ((skb->len > dst_mtu(skb->dst) && !skb_is_gso(skb)) ||
 				dst_allfrag(skb->dst))
 		return ip6_fragment(skb, ip6_output2);
 	else
@@ -229,7 +229,7 @@
 	skb->priority = sk->sk_priority;
 
 	mtu = dst_mtu(dst);
-	if ((skb->len <= mtu) || ipfragok || skb_shinfo(skb)->gso_size) {
+	if ((skb->len <= mtu) || ipfragok || skb_is_gso(skb)) {
 		IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
 		return NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev,
 				dst_output);
diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
index 48fccb1..0eea60e 100644
--- a/net/ipv6/xfrm6_output.c
+++ b/net/ipv6/xfrm6_output.c
@@ -122,7 +122,7 @@
 {
 	struct sk_buff *segs;
 
-	if (!skb_shinfo(skb)->gso_size)
+	if (!skb_is_gso(skb))
 		return xfrm6_output_finish2(skb);
 
 	skb->protocol = htons(ETH_P_IP);