[PATCH 4.4 64/74] tcp: __tcp_hdrlen() helper

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Craig Gallek <kraig@xxxxxxxxxx>

commit d9b3fca27385eafe61c3ca6feab6cb1e7dc77482 upstream.

tcp_hdrlen is wasteful if you already have a pointer to struct tcphdr.
This splits the size calculation into a helper function that can be
used if a struct tcphdr is already available.

Signed-off-by: Craig Gallek <kraig@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 include/linux/tcp.h |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -29,9 +29,14 @@ static inline struct tcphdr *tcp_hdr(con
 	return (struct tcphdr *)skb_transport_header(skb);
 }
 
+static inline unsigned int __tcp_hdrlen(const struct tcphdr *th)
+{
+	return th->doff * 4;
+}
+
 static inline unsigned int tcp_hdrlen(const struct sk_buff *skb)
 {
-	return tcp_hdr(skb)->doff * 4;
+	return __tcp_hdrlen(tcp_hdr(skb));
 }
 
 static inline struct tcphdr *inner_tcp_hdr(const struct sk_buff *skb)