tcp: __tcp_hdrlen() helper

kraigatgoog · davem330 · commit d9b3fca27385 · 2016-02-11T03:54:14.000-05:00
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 &lt;kraig@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
@@ -29,9 +29,14 @@ static inline struct tcphdr *tcp_hdr(const struct sk_buff *skb)
 	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)

Original file line number	Diff line number	Diff line change
`@@ -29,9 +29,14 @@ static inline struct tcphdr tcp_hdr(const struct sk_buff skb)`
`29`	`29`	`return (struct tcphdr *)skb_transport_header(skb);`
`30`	`30`	`}`
`31`	`31`
	`32`	`+static inline unsigned int __tcp_hdrlen(const struct tcphdr *th)`
	`33`	`+{`
	`34`	`+ return th->doff * 4;`
	`35`	`+}`
	`36`	`+`
`32`	`37`	`static inline unsigned int tcp_hdrlen(const struct sk_buff *skb)`
`33`	`38`	`{`
`34`		`- return tcp_hdr(skb)->doff * 4;`
	`39`	`+ return __tcp_hdrlen(tcp_hdr(skb));`
`35`	`40`	`}`
`36`	`41`
`37`	`42`	`static inline struct tcphdr inner_tcp_hdr(const struct sk_buff skb)`