[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>

4 files changed, 14 insertions, 17 deletions

diff --git a/net/ipv4/ipvs/ip_vs_app.c b/net/ipv4/ipvs/ip_vs_app.c
index f29d3a2..e5beab2 100644
--- a/net/ipv4/ipvs/ip_vs_app.c
+++ b/net/ipv4/ipvs/ip_vs_app.c
@@ -331,7 +331,7 @@ static inline int app_tcp_pkt_out(struct ip_vs_conn *cp, struct sk_buff **pskb,
 				  struct ip_vs_app *app)
 {
 	int diff;
-	unsigned int tcp_offset = (*pskb)->nh.iph->ihl*4;
+	const unsigned int tcp_offset = ip_hdrlen(*pskb);
 	struct tcphdr *th;
 	__u32 seq;
 
@@ -406,7 +406,7 @@ static inline int app_tcp_pkt_in(struct ip_vs_conn *cp, struct sk_buff **pskb,
 				 struct ip_vs_app *app)
 {
 	int diff;
-	unsigned int tcp_offset = (*pskb)->nh.iph->ihl*4;
+	const unsigned int tcp_offset = ip_hdrlen(*pskb);
 	struct tcphdr *th;
 	__u32 seq;
 
diff --git a/net/ipv4/ipvs/ip_vs_core.c b/net/ipv4/ipvs/ip_vs_core.c
index 5d54dd2..7893c00 100644
--- a/net/ipv4/ipvs/ip_vs_core.c
+++ b/net/ipv4/ipvs/ip_vs_core.c
@@ -713,8 +713,7 @@ static inline int is_tcp_reset(const struct sk_buff *skb)
 {
 	struct tcphdr _tcph, *th;
 
-	th = skb_header_pointer(skb, skb->nh.iph->ihl * 4,
-				sizeof(_tcph), &_tcph);
+	th = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph);
 	if (th == NULL)
 		return 0;
 	return th->rst;
diff --git a/net/ipv4/ipvs/ip_vs_proto_tcp.c b/net/ipv4/ipvs/ip_vs_proto_tcp.c
index 16a9ebe..e65382d 100644
--- a/net/ipv4/ipvs/ip_vs_proto_tcp.c
+++ b/net/ipv4/ipvs/ip_vs_proto_tcp.c
@@ -76,8 +76,7 @@ tcp_conn_schedule(struct sk_buff *skb,
 	struct ip_vs_service *svc;
 	struct tcphdr _tcph, *th;
 
-	th = skb_header_pointer(skb, skb->nh.iph->ihl*4,
-				sizeof(_tcph), &_tcph);
+	th = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph);
 	if (th == NULL) {
 		*verdict = NF_DROP;
 		return 0;
@@ -127,7 +126,7 @@ tcp_snat_handler(struct sk_buff **pskb,
 		 struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
 {
 	struct tcphdr *tcph;
-	unsigned int tcphoff = (*pskb)->nh.iph->ihl * 4;
+	const unsigned int tcphoff = ip_hdrlen(*pskb);
 
 	/* csum_check requires unshared skb */
 	if (!ip_vs_make_skb_writable(pskb, tcphoff+sizeof(*tcph)))
@@ -175,7 +174,7 @@ tcp_dnat_handler(struct sk_buff **pskb,
 		 struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
 {
 	struct tcphdr *tcph;
-	unsigned int tcphoff = (*pskb)->nh.iph->ihl * 4;
+	const unsigned int tcphoff = ip_hdrlen(*pskb);
 
 	/* csum_check requires unshared skb */
 	if (!ip_vs_make_skb_writable(pskb, tcphoff+sizeof(*tcph)))
@@ -224,7 +223,7 @@ tcp_dnat_handler(struct sk_buff **pskb,
 static int
 tcp_csum_check(struct sk_buff *skb, struct ip_vs_protocol *pp)
 {
-	unsigned int tcphoff = skb->nh.iph->ihl*4;
+	const unsigned int tcphoff = ip_hdrlen(skb);
 
 	switch (skb->ip_summed) {
 	case CHECKSUM_NONE:
@@ -467,8 +466,7 @@ tcp_state_transition(struct ip_vs_conn *cp, int direction,
 {
 	struct tcphdr _tcph, *th;
 
-	th = skb_header_pointer(skb, skb->nh.iph->ihl*4,
-				sizeof(_tcph), &_tcph);
+	th = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph);
 	if (th == NULL)
 		return 0;
 
diff --git a/net/ipv4/ipvs/ip_vs_proto_udp.c b/net/ipv4/ipvs/ip_vs_proto_udp.c
index 03f0a41..2cd9506 100644
--- a/net/ipv4/ipvs/ip_vs_proto_udp.c
+++ b/net/ipv4/ipvs/ip_vs_proto_udp.c
@@ -22,7 +22,7 @@
 #include <linux/udp.h>
 
 #include <net/ip_vs.h>
-
+#include <net/ip.h>
 
 static struct ip_vs_conn *
 udp_conn_in_get(const struct sk_buff *skb, struct ip_vs_protocol *pp,
@@ -56,7 +56,7 @@ udp_conn_out_get(const struct sk_buff *skb, struct ip_vs_protocol *pp,
 	struct ip_vs_conn *cp;
 	__be16 _ports[2], *pptr;
 
-	pptr = skb_header_pointer(skb, skb->nh.iph->ihl*4,
+	pptr = skb_header_pointer(skb, ip_hdrlen(skb),
 				  sizeof(_ports), _ports);
 	if (pptr == NULL)
 		return NULL;
@@ -82,7 +82,7 @@ udp_conn_schedule(struct sk_buff *skb, struct ip_vs_protocol *pp,
 	struct ip_vs_service *svc;
 	struct udphdr _udph, *uh;
 
-	uh = skb_header_pointer(skb, skb->nh.iph->ihl*4,
+	uh = skb_header_pointer(skb, ip_hdrlen(skb),
 				sizeof(_udph), &_udph);
 	if (uh == NULL) {
 		*verdict = NF_DROP;
@@ -133,7 +133,7 @@ udp_snat_handler(struct sk_buff **pskb,
 		 struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
 {
 	struct udphdr *udph;
-	unsigned int udphoff = (*pskb)->nh.iph->ihl * 4;
+	const unsigned int udphoff = ip_hdrlen(*pskb);
 
 	/* csum_check requires unshared skb */
 	if (!ip_vs_make_skb_writable(pskb, udphoff+sizeof(*udph)))
@@ -187,7 +187,7 @@ udp_dnat_handler(struct sk_buff **pskb,
 		 struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
 {
 	struct udphdr *udph;
-	unsigned int udphoff = (*pskb)->nh.iph->ihl * 4;
+	unsigned int udphoff = ip_hdrlen(*pskb);
 
 	/* csum_check requires unshared skb */
 	if (!ip_vs_make_skb_writable(pskb, udphoff+sizeof(*udph)))
@@ -239,7 +239,7 @@ static int
 udp_csum_check(struct sk_buff *skb, struct ip_vs_protocol *pp)
 {
 	struct udphdr _udph, *uh;
-	unsigned int udphoff = skb->nh.iph->ihl*4;
+	const unsigned int udphoff = ip_hdrlen(skb);
 
 	uh = skb_header_pointer(skb, udphoff, sizeof(_udph), &_udph);
 	if (uh == NULL)