[IP]: Introduce ip_hdrlen()

For the common sequence "skb->nh.iph->ihl * 4", removing a good number of open
coded skb->nh.iph uses, now to go after the rest...

Just out of curiosity, here are the idioms found to get the same result:

skb->nh.iph->ihl << 2
skb->nh.iph->ihl<<2
skb->nh.iph->ihl * 4
skb->nh.iph->ihl*4
(skb->nh.iph)->ihl * sizeof(u32)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 1 deletions

diff --git a/include/net/ip.h b/include/net/ip.h
index e79c3e3aa4f6..6f7ba32b199d 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -25,6 +25,7 @@
 #include <linux/types.h>
 #include <linux/ip.h>
 #include <linux/in.h>
+#include <linux/skbuff.h>
 
 #include <net/inet_sock.h>
 #include <net/snmp.h>
@@ -43,6 +44,11 @@ struct inet_skb_parm
 #define IPSKB_REROUTED          16
 };
 
+static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
+{
+        return skb->nh.iph->ihl * 4;
+}
+
 struct ipcm_cookie
 {
         __be32                  addr;
@@ -74,7 +80,6 @@ struct msghdr;
 struct net_device;
 struct packet_type;
 struct rtable;
-struct sk_buff;
 struct sockaddr;
 
 extern void             ip_mc_dropsocket(struct sock *);