[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>

37 files changed, 113 insertions, 120 deletions

diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 268a6c7..af120b2 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -483,7 +483,7 @@ static void ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
 	flags = offset & ~IP_OFFSET;
 	offset &= IP_OFFSET;
 	offset <<= 3;		/* offset is in 8-byte chunks */
-	ihl = skb->nh.iph->ihl * 4;
+	ihl = ip_hdrlen(skb);
 
 	/* Determine the position of this fragment. */
 	end = offset + skb->len - ihl;
@@ -624,7 +624,7 @@ static struct sk_buff *ip_frag_reasm(struct ipq *qp, struct net_device *dev)
 	BUG_TRAP(FRAG_CB(head)->offset == 0);
 
 	/* Allocate a new buffer for the datagram. */
-	ihlen = head->nh.iph->ihl*4;
+	ihlen = ip_hdrlen(head);
 	len = ihlen + qp->len;
 
 	if (len > 65535)
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index f38e976..2ee132b 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -198,9 +198,7 @@ int ip_call_ra_chain(struct sk_buff *skb)
 
 static inline int ip_local_deliver_finish(struct sk_buff *skb)
 {
-	int ihl = skb->nh.iph->ihl*4;
-
-	__skb_pull(skb, ihl);
+	__skb_pull(skb, ip_hdrlen(skb));
 
 	/* Point into the IP datagram, just past the header. */
 	skb->h.raw = skb->data;
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index aba3ff0..54b7543 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -539,7 +539,7 @@ static void ipmr_cache_resolve(struct mfc_cache *uc, struct mfc_cache *c)
 static int ipmr_cache_report(struct sk_buff *pkt, vifi_t vifi, int assert)
 {
 	struct sk_buff *skb;
-	int ihl = pkt->nh.iph->ihl<<2;
+	const int ihl = ip_hdrlen(pkt);
 	struct igmphdr *igmp;
 	struct igmpmsg *msg;
 	int ret;
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)
diff --git a/net/ipv4/netfilter/ip_conntrack_amanda.c b/net/ipv4/netfilter/ip_conntrack_amanda.c
index 4f561f5..c40762c 100644
--- a/net/ipv4/netfilter/ip_conntrack_amanda.c
+++ b/net/ipv4/netfilter/ip_conntrack_amanda.c
@@ -103,7 +103,7 @@ static int help(struct sk_buff **pskb,
 	ip_ct_refresh(ct, *pskb, master_timeout * HZ);
 
 	/* No data? */
-	dataoff = (*pskb)->nh.iph->ihl*4 + sizeof(struct udphdr);
+	dataoff = ip_hdrlen(*pskb) + sizeof(struct udphdr);
 	if (dataoff >= (*pskb)->len) {
 		if (net_ratelimit())
 			printk("amanda_help: skblen = %u\n", (*pskb)->len);
diff --git a/net/ipv4/netfilter/ip_conntrack_core.c b/net/ipv4/netfilter/ip_conntrack_core.c
index 23b99ae..8c013d9f 100644
--- a/net/ipv4/netfilter/ip_conntrack_core.c
+++ b/net/ipv4/netfilter/ip_conntrack_core.c
@@ -750,8 +750,7 @@ resolve_normal_ct(struct sk_buff *skb,
 
 	IP_NF_ASSERT((skb->nh.iph->frag_off & htons(IP_OFFSET)) == 0);
 
-	if (!ip_ct_get_tuple(skb->nh.iph, skb, skb->nh.iph->ihl*4,
-				&tuple,proto))
+	if (!ip_ct_get_tuple(skb->nh.iph, skb, ip_hdrlen(skb), &tuple,proto))
 		return NULL;
 
 	/* look for tuple match */
diff --git a/net/ipv4/netfilter/ip_conntrack_ftp.c b/net/ipv4/netfilter/ip_conntrack_ftp.c
index 1faa68a..9238998 100644
--- a/net/ipv4/netfilter/ip_conntrack_ftp.c
+++ b/net/ipv4/netfilter/ip_conntrack_ftp.c
@@ -319,12 +319,12 @@ static int help(struct sk_buff **pskb,
 		return NF_ACCEPT;
 	}
 
-	th = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl*4,
+	th = skb_header_pointer(*pskb, ip_hdrlen(*pskb),
 				sizeof(_tcph), &_tcph);
 	if (th == NULL)
 		return NF_ACCEPT;
 
-	dataoff = (*pskb)->nh.iph->ihl*4 + th->doff*4;
+	dataoff = ip_hdrlen(*pskb) + th->doff * 4;
 	/* No data? */
 	if (dataoff >= (*pskb)->len) {
 		DEBUGP("ftp: pskblen = %u\n", (*pskb)->len);
diff --git a/net/ipv4/netfilter/ip_conntrack_helper_h323.c b/net/ipv4/netfilter/ip_conntrack_helper_h323.c
index 53eb365..5d63814 100644
--- a/net/ipv4/netfilter/ip_conntrack_helper_h323.c
+++ b/net/ipv4/netfilter/ip_conntrack_helper_h323.c
@@ -115,13 +115,13 @@ static int get_tpkt_data(struct sk_buff **pskb, struct ip_conntrack *ct,
 	int tpktoff;
 
 	/* Get TCP header */
-	th = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl * 4,
+	th = skb_header_pointer(*pskb, ip_hdrlen(*pskb),
 				sizeof(_tcph), &_tcph);
 	if (th == NULL)
 		return 0;
 
 	/* Get TCP data offset */
-	tcpdataoff = (*pskb)->nh.iph->ihl * 4 + th->doff * 4;
+	tcpdataoff = ip_hdrlen(*pskb) + th->doff * 4;
 
 	/* Get TCP data length */
 	tcpdatalen = (*pskb)->len - tcpdataoff;
@@ -1185,11 +1185,10 @@ static unsigned char *get_udp_data(struct sk_buff **pskb, int *datalen)
 	struct udphdr _uh, *uh;
 	int dataoff;
 
-	uh = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl * 4, sizeof(_uh),
-				&_uh);
+	uh = skb_header_pointer(*pskb, ip_hdrlen(*pskb), sizeof(_uh), &_uh);
 	if (uh == NULL)
 		return NULL;
-	dataoff = (*pskb)->nh.iph->ihl * 4 + sizeof(_uh);
+	dataoff = ip_hdrlen(*pskb) + sizeof(_uh);
 	if (dataoff >= (*pskb)->len)
 		return NULL;
 	*datalen = (*pskb)->len - dataoff;
diff --git a/net/ipv4/netfilter/ip_conntrack_helper_pptp.c b/net/ipv4/netfilter/ip_conntrack_helper_pptp.c
index 2b760c5..f5ab8e4 100644
--- a/net/ipv4/netfilter/ip_conntrack_helper_pptp.c
+++ b/net/ipv4/netfilter/ip_conntrack_helper_pptp.c
@@ -543,7 +543,7 @@ conntrack_pptp_help(struct sk_buff **pskb,
 	struct pptp_pkt_hdr _pptph, *pptph;
 	struct PptpControlHeader _ctlh, *ctlh;
 	union pptp_ctrl_union _pptpReq, *pptpReq;
-	unsigned int tcplen = (*pskb)->len - (*pskb)->nh.iph->ihl * 4;
+	unsigned int tcplen = (*pskb)->len - ip_hdrlen(*pskb);
 	unsigned int datalen, reqlen, nexthdr_off;
 	int oldsstate, oldcstate;
 	int ret;
@@ -556,7 +556,7 @@ conntrack_pptp_help(struct sk_buff **pskb,
 		return NF_ACCEPT;
 	}
 
-	nexthdr_off = (*pskb)->nh.iph->ihl*4;
+	nexthdr_off = ip_hdrlen(*pskb);
 	tcph = skb_header_pointer(*pskb, nexthdr_off, sizeof(_tcph), &_tcph);
 	BUG_ON(!tcph);
 	nexthdr_off += tcph->doff * 4;
diff --git a/net/ipv4/netfilter/ip_conntrack_irc.c b/net/ipv4/netfilter/ip_conntrack_irc.c
index 053e591..ee99abe 100644
--- a/net/ipv4/netfilter/ip_conntrack_irc.c
+++ b/net/ipv4/netfilter/ip_conntrack_irc.c
@@ -130,13 +130,13 @@ static int help(struct sk_buff **pskb,
 	}
 
 	/* Not a full tcp header? */
-	th = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl*4,
+	th = skb_header_pointer(*pskb, ip_hdrlen(*pskb),
 				sizeof(_tcph), &_tcph);
 	if (th == NULL)
 		return NF_ACCEPT;
 
 	/* No data? */
-	dataoff = (*pskb)->nh.iph->ihl*4 + th->doff*4;
+	dataoff = ip_hdrlen(*pskb) + th->doff * 4;
 	if (dataoff >= (*pskb)->len)
 		return NF_ACCEPT;
 
diff --git a/net/ipv4/netfilter/ip_conntrack_proto_icmp.c b/net/ipv4/netfilter/ip_conntrack_proto_icmp.c
index ad70c81..e253f3e 100644
--- a/net/ipv4/netfilter/ip_conntrack_proto_icmp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_icmp.c
@@ -149,7 +149,7 @@ icmp_error_message(struct sk_buff *skb,
 	IP_NF_ASSERT(skb->nfct == NULL);
 
 	/* Not enough header? */
-	inside = skb_header_pointer(skb, skb->nh.iph->ihl*4, sizeof(_in), &_in);
+	inside = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_in), &_in);
 	if (inside == NULL)
 		return -NF_ACCEPT;
 
@@ -161,7 +161,7 @@ icmp_error_message(struct sk_buff *skb,
 	}
 
 	innerproto = ip_conntrack_proto_find_get(inside->ip.protocol);
-	dataoff = skb->nh.iph->ihl*4 + sizeof(inside->icmp) + inside->ip.ihl*4;
+	dataoff = ip_hdrlen(skb) + sizeof(inside->icmp) + inside->ip.ihl * 4;
 	/* Are they talking about one of our connections? */
 	if (!ip_ct_get_tuple(&inside->ip, skb, dataoff, &origtuple, innerproto)) {
 		DEBUGP("icmp_error: ! get_tuple p=%u", inside->ip.protocol);
@@ -214,7 +214,7 @@ icmp_error(struct sk_buff *skb, enum ip_conntrack_info *ctinfo,
 	struct icmphdr _ih, *icmph;
 
 	/* Not enough header? */
-	icmph = skb_header_pointer(skb, skb->nh.iph->ihl*4, sizeof(_ih), &_ih);
+	icmph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_ih), &_ih);
 	if (icmph == NULL) {
 		if (LOG_INVALID(IPPROTO_ICMP))
 			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
@@ -224,7 +224,7 @@ icmp_error(struct sk_buff *skb, enum ip_conntrack_info *ctinfo,
 
 	/* See ip_conntrack_proto_tcp.c */
 	if (ip_conntrack_checksum && hooknum == NF_IP_PRE_ROUTING &&
-	    nf_ip_checksum(skb, hooknum, skb->nh.iph->ihl * 4, 0)) {
+	    nf_ip_checksum(skb, hooknum, ip_hdrlen(skb), 0)) {
 		if (LOG_INVALID(IPPROTO_ICMP))
 			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
 				      "ip_ct_icmp: bad ICMP checksum ");
diff --git a/net/ipv4/netfilter/ip_conntrack_proto_sctp.c b/net/ipv4/netfilter/ip_conntrack_proto_sctp.c
index e694299..e29c436 100644
--- a/net/ipv4/netfilter/ip_conntrack_proto_sctp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_sctp.c
@@ -206,7 +206,7 @@ static int sctp_print_conntrack(struct seq_file *s,
 }
 
 #define for_each_sctp_chunk(skb, sch, _sch, offset, count)		\
-for (offset = skb->nh.iph->ihl * 4 + sizeof(sctp_sctphdr_t), count = 0;	\
+for (offset = ip_hdrlen(skb) + sizeof(sctp_sctphdr_t), count = 0;	\
 	offset < skb->len &&						\
 	(sch = skb_header_pointer(skb, offset, sizeof(_sch), &_sch));	\
 	offset += (ntohs(sch->length) + 3) & ~3, count++)
diff --git a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
index 7ff1197..fce3a3c 100644
--- a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
@@ -771,7 +771,7 @@ void ip_conntrack_tcp_update(struct sk_buff *skb,
 			     enum ip_conntrack_dir dir)
 {
 	struct iphdr *iph = skb->nh.iph;
-	struct tcphdr *tcph = (void *)skb->nh.iph + skb->nh.iph->ihl*4;
+	struct tcphdr *tcph = (void *)skb->nh.iph + ip_hdrlen(skb);
 	__u32 end;
 #ifdef DEBUGP_VARS
 	struct ip_ct_tcp_state *sender = &conntrack->proto.tcp.seen[dir];
diff --git a/net/ipv4/netfilter/ip_conntrack_sip.c b/net/ipv4/netfilter/ip_conntrack_sip.c
index c59a962..7363e2a 100644
--- a/net/ipv4/netfilter/ip_conntrack_sip.c
+++ b/net/ipv4/netfilter/ip_conntrack_sip.c
@@ -402,7 +402,7 @@ static int sip_help(struct sk_buff **pskb,
 	typeof(ip_nat_sip_hook) ip_nat_sip;
 
 	/* No Data ? */
-	dataoff = (*pskb)->nh.iph->ihl*4 + sizeof(struct udphdr);
+	dataoff = ip_hdrlen(*pskb) + sizeof(struct udphdr);
 	if (dataoff >= (*pskb)->len) {
 		DEBUGP("skb->len = %u\n", (*pskb)->len);
 		return NF_ACCEPT;
diff --git a/net/ipv4/netfilter/ip_conntrack_standalone.c b/net/ipv4/netfilter/ip_conntrack_standalone.c
index 56b2f75..92609a4 100644
--- a/net/ipv4/netfilter/ip_conntrack_standalone.c
+++ b/net/ipv4/netfilter/ip_conntrack_standalone.c
@@ -458,7 +458,7 @@ static unsigned int ip_conntrack_local(unsigned int hooknum,
 {
 	/* root is playing with raw sockets. */
 	if ((*pskb)->len < sizeof(struct iphdr)
-	    || (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr)) {
+	    || ip_hdrlen(*pskb) < sizeof(struct iphdr)) {
 		if (net_ratelimit())
 			printk("ipt_hook: happy cracking.\n");
 		return NF_ACCEPT;
diff --git a/net/ipv4/netfilter/ip_conntrack_tftp.c b/net/ipv4/netfilter/ip_conntrack_tftp.c
index 76e175e..afc6809 100644
--- a/net/ipv4/netfilter/ip_conntrack_tftp.c
+++ b/net/ipv4/netfilter/ip_conntrack_tftp.c
@@ -53,7 +53,7 @@ static int tftp_help(struct sk_buff **pskb,
 	typeof(ip_nat_tftp_hook) ip_nat_tftp;
 
 	tfh = skb_header_pointer(*pskb,
-				 (*pskb)->nh.iph->ihl*4+sizeof(struct udphdr),
+				 ip_hdrlen(*pskb) + sizeof(struct udphdr),
 				 sizeof(_tftph), &_tftph);
 	if (tfh == NULL)
 		return NF_ACCEPT;
diff --git a/net/ipv4/netfilter/ip_nat_core.c b/net/ipv4/netfilter/ip_nat_core.c
index 40737fd..cf46930 100644
--- a/net/ipv4/netfilter/ip_nat_core.c
+++ b/net/ipv4/netfilter/ip_nat_core.c
@@ -422,7 +422,7 @@ int ip_nat_icmp_reply_translation(struct ip_conntrack *ct,
 	} *inside;
 	struct ip_conntrack_protocol *proto;
 	struct ip_conntrack_tuple inner, target;
-	int hdrlen = (*pskb)->nh.iph->ihl * 4;
+	int hdrlen = ip_hdrlen(*pskb);
 	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
 	unsigned long statusbit;
 	enum ip_nat_manip_type manip = HOOK2MANIP(hooknum);
@@ -430,7 +430,7 @@ int ip_nat_icmp_reply_translation(struct ip_conntrack *ct,
 	if (!skb_make_writable(pskb, hdrlen + sizeof(*inside)))
 		return 0;
 
-	inside = (void *)(*pskb)->data + (*pskb)->nh.iph->ihl*4;
+	inside = (void *)(*pskb)->data + ip_hdrlen(*pskb);
 
 	/* We're actually going to mangle it beyond trivial checksum
 	   adjustment, so make sure the current checksum is correct. */
@@ -458,7 +458,7 @@ int ip_nat_icmp_reply_translation(struct ip_conntrack *ct,
 
 	/* rcu_read_lock()ed by nf_hook_slow */
 	proto = __ip_conntrack_proto_find(inside->ip.protocol);
-	if (!ip_ct_get_tuple(&inside->ip, *pskb, (*pskb)->nh.iph->ihl*4 +
+	if (!ip_ct_get_tuple(&inside->ip, *pskb, ip_hdrlen(*pskb) +
 			     sizeof(struct icmphdr) + inside->ip.ihl*4,
 			     &inner, proto))
 		return 0;
@@ -469,15 +469,14 @@ int ip_nat_icmp_reply_translation(struct ip_conntrack *ct,
 	   packet: PREROUTING (DST manip), routing produces ICMP, goes
 	   through POSTROUTING (which must correct the DST manip). */
 	if (!manip_pkt(inside->ip.protocol, pskb,
-		       (*pskb)->nh.iph->ihl*4
-		       + sizeof(inside->icmp),
+		       ip_hdrlen(*pskb) + sizeof(inside->icmp),
 		       &ct->tuplehash[!dir].tuple,
 		       !manip))
 		return 0;
 
 	if ((*pskb)->ip_summed != CHECKSUM_PARTIAL) {
 		/* Reloading "inside" here since manip_pkt inner. */
-		inside = (void *)(*pskb)->data + (*pskb)->nh.iph->ihl*4;
+		inside = (void *)(*pskb)->data + ip_hdrlen(*pskb);
 		inside->icmp.checksum = 0;
 		inside->icmp.checksum = csum_fold(skb_checksum(*pskb, hdrlen,
 							       (*pskb)->len - hdrlen,
diff --git a/net/ipv4/netfilter/ip_nat_helper.c b/net/ipv4/netfilter/ip_nat_helper.c
index dc778cf..25624e5 100644
--- a/net/ipv4/netfilter/ip_nat_helper.c
+++ b/net/ipv4/netfilter/ip_nat_helper.c
@@ -322,8 +322,8 @@ ip_nat_sack_adjust(struct sk_buff **pskb,
 {
 	unsigned int dir, optoff, optend;
 
-	optoff = (*pskb)->nh.iph->ihl*4 + sizeof(struct tcphdr);
-	optend = (*pskb)->nh.iph->ihl*4 + tcph->doff*4;
+	optoff = ip_hdrlen(*pskb) + sizeof(struct tcphdr);
+	optend = ip_hdrlen(*pskb) + tcph->doff * 4;
 
 	if (!skb_make_writable(pskb, optend))
 		return 0;
@@ -374,10 +374,10 @@ ip_nat_seq_adjust(struct sk_buff **pskb,
 	this_way = &ct->nat.info.seq[dir];
 	other_way = &ct->nat.info.seq[!dir];
 
-	if (!skb_make_writable(pskb, (*pskb)->nh.iph->ihl*4+sizeof(*tcph)))
+	if (!skb_make_writable(pskb, ip_hdrlen(*pskb) + sizeof(*tcph)))
 		return 0;
 
-	tcph = (void *)(*pskb)->data + (*pskb)->nh.iph->ihl*4;
+	tcph = (void *)(*pskb)->data + ip_hdrlen(*pskb);
 	if (after(ntohl(tcph->seq), this_way->correction_pos))
 		newseq = htonl(ntohl(tcph->seq) + this_way->offset_after);
 	else
diff --git a/net/ipv4/netfilter/ip_nat_helper_h323.c b/net/ipv4/netfilter/ip_nat_helper_h323.c
index bdc99ef..8b1e338 100644
--- a/net/ipv4/netfilter/ip_nat_helper_h323.c
+++ b/net/ipv4/netfilter/ip_nat_helper_h323.c
@@ -57,11 +57,11 @@ static int set_addr(struct sk_buff **pskb,
 		}
 
 		/* Relocate data pointer */
-		th = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl * 4,
+		th = skb_header_pointer(*pskb, ip_hdrlen(*pskb),
 					sizeof(_tcph), &_tcph);
 		if (th == NULL)
 			return -1;
-		*data = (*pskb)->data + (*pskb)->nh.iph->ihl * 4 +
+		*data = (*pskb)->data + ip_hdrlen(*pskb) +
 		    th->doff * 4 + dataoff;
 	} else {
 		if (!ip_nat_mangle_udp_packet(pskb, ct, ctinfo,
@@ -75,8 +75,8 @@ static int set_addr(struct sk_buff **pskb,
 		/* ip_nat_mangle_udp_packet uses skb_make_writable() to copy
 		 * or pull everything in a linear buffer, so we can safely
 		 * use the skb pointers now */
-		*data = (*pskb)->data + (*pskb)->nh.iph->ihl * 4 +
-		    sizeof(struct udphdr);
+		*data = ((*pskb)->data + ip_hdrlen(*pskb) +
+			 sizeof(struct udphdr));
 	}
 
 	return 0;
diff --git a/net/ipv4/netfilter/ip_nat_sip.c b/net/ipv4/netfilter/ip_nat_sip.c
index 325c5a9..8495360 100644
--- a/net/ipv4/netfilter/ip_nat_sip.c
+++ b/net/ipv4/netfilter/ip_nat_sip.c
@@ -90,7 +90,7 @@ static int map_sip_addr(struct sk_buff **pskb, enum ip_conntrack_info ctinfo,
 	if (!ip_nat_mangle_udp_packet(pskb, ct, ctinfo,
 				      matchoff, matchlen, addr, addrlen))
 		return 0;
-	*dptr = (*pskb)->data + (*pskb)->nh.iph->ihl*4 + sizeof(struct udphdr);
+	*dptr = (*pskb)->data + ip_hdrlen(*pskb) + sizeof(struct udphdr);
 	return 1;
 
 }
@@ -104,7 +104,7 @@ static unsigned int ip_nat_sip(struct sk_buff **pskb,
 	struct addr_map map;
 	int dataoff, datalen;
 
-	dataoff = (*pskb)->nh.iph->ihl*4 + sizeof(struct udphdr);
+	dataoff = ip_hdrlen(*pskb) + sizeof(struct udphdr);
 	datalen = (*pskb)->len - dataoff;
 	if (datalen < sizeof("SIP/2.0") - 1)
 		return NF_DROP;
@@ -153,7 +153,7 @@ static unsigned int mangle_sip_packet(struct sk_buff **pskb,
 		return 0;
 
 	/* We need to reload this. Thanks Patrick. */
-	*dptr = (*pskb)->data + (*pskb)->nh.iph->ihl*4 + sizeof(struct udphdr);
+	*dptr = (*pskb)->data + ip_hdrlen(*pskb) + sizeof(struct udphdr);
 	return 1;
 }
 
@@ -166,7 +166,7 @@ static int mangle_content_len(struct sk_buff **pskb,
 	char buffer[sizeof("65536")];
 	int bufflen;
 
-	dataoff = (*pskb)->nh.iph->ihl*4 + sizeof(struct udphdr);
+	dataoff = ip_hdrlen(*pskb) + sizeof(struct udphdr);
 
 	/* Get actual SDP lenght */
 	if (ct_sip_get_info(dptr, (*pskb)->len - dataoff, &matchoff,
@@ -199,7 +199,7 @@ static unsigned int mangle_sdp(struct sk_buff **pskb,
 	char buffer[sizeof("nnn.nnn.nnn.nnn")];
 	unsigned int dataoff, bufflen;
 
-	dataoff = (*pskb)->nh.iph->ihl*4 + sizeof(struct udphdr);
+	dataoff = ip_hdrlen(*pskb) + sizeof(struct udphdr);
 
 	/* Mangle owner and contact info. */
 	bufflen = sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(newip));
diff --git a/net/ipv4/netfilter/ip_nat_standalone.c b/net/ipv4/netfilter/ip_nat_standalone.c
index 6bcfdf6..dbaaf78 100644
--- a/net/ipv4/netfilter/ip_nat_standalone.c
+++ b/net/ipv4/netfilter/ip_nat_standalone.c
@@ -112,8 +112,7 @@ ip_nat_fn(unsigned int hooknum,
 		if ((*pskb)->nh.iph->protocol == IPPROTO_ICMP) {
 			struct icmphdr _hdr, *hp;
 
-			hp = skb_header_pointer(*pskb,
-						(*pskb)->nh.iph->ihl*4,
+			hp = skb_header_pointer(*pskb, ip_hdrlen(*pskb),
 						sizeof(_hdr), &_hdr);
 			if (hp != NULL &&
 			    hp->type == ICMP_REDIRECT)
@@ -211,7 +210,7 @@ ip_nat_out(unsigned int hooknum,
 
 	/* root is playing with raw sockets. */
 	if ((*pskb)->len < sizeof(struct iphdr)
-	    || (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr))
+	    || ip_hdrlen(*pskb) < sizeof(struct iphdr))
 		return NF_ACCEPT;
 
 	ret = ip_nat_fn(hooknum, pskb, in, out, okfn);
@@ -244,7 +243,7 @@ ip_nat_local_fn(unsigned int hooknum,
 
 	/* root is playing with raw sockets. */
 	if ((*pskb)->len < sizeof(struct iphdr)
-	    || (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr))
+	    || ip_hdrlen(*pskb) < sizeof(struct iphdr))
 		return NF_ACCEPT;
 
 	ret = ip_nat_fn(hooknum, pskb, in, out, okfn);
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 50cc4b9..f669666 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -198,7 +198,7 @@ int do_match(struct ipt_entry_match *m,
 {
 	/* Stop iteration if it doesn't match */
 	if (!m->u.kernel.match->match(skb, in, out, m->u.kernel.match, m->data,
-				      offset, skb->nh.iph->ihl*4, hotdrop))
+				      offset, ip_hdrlen(skb), hotdrop))
 		return 1;
 	else
 		return 0;
diff --git a/net/ipv4/netfilter/ipt_ECN.c b/net/ipv4/netfilter/ipt_ECN.c
index 4f56563..44daf9e 100644
--- a/net/ipv4/netfilter/ipt_ECN.c
+++ b/net/ipv4/netfilter/ipt_ECN.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/skbuff.h>
 #include <linux/ip.h>
+#include <net/ip.h>
 #include <linux/tcp.h>
 #include <net/checksum.h>
 
@@ -52,7 +53,7 @@ set_ect_tcp(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
 	__be16 oldval;
 
 	/* Not enought header? */
-	tcph = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl*4,
+	tcph = skb_header_pointer(*pskb, ip_hdrlen(*pskb),
 				  sizeof(_tcph), &_tcph);
 	if (!tcph)
 		return 0;
@@ -63,9 +64,9 @@ set_ect_tcp(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
 	     tcph->cwr == einfo->proto.tcp.cwr)))
 		return 1;
 
-	if (!skb_make_writable(pskb, (*pskb)->nh.iph->ihl*4+sizeof(*tcph)))
+	if (!skb_make_writable(pskb, ip_hdrlen(*pskb) + sizeof(*tcph)))
 		return 0;
-	tcph = (void *)(*pskb)->nh.iph + (*pskb)->nh.iph->ihl*4;
+	tcph = (void *)(*pskb)->nh.iph + ip_hdrlen(*pskb);
 
 	oldval = ((__be16 *)tcph)[6];
 	if (einfo->operation & IPT_ECN_OP_SET_ECE)
diff --git a/net/ipv4/netfilter/ipt_REJECT.c b/net/ipv4/netfilter/ipt_REJECT.c
index 80f739e..01c04f0 100644
--- a/net/ipv4/netfilter/ipt_REJECT.c
+++ b/net/ipv4/netfilter/ipt_REJECT.c
@@ -43,7 +43,6 @@ MODULE_DESCRIPTION("iptables REJECT target module");
 static void send_reset(struct sk_buff *oldskb, int hook)
 {
 	struct sk_buff *nskb;
-	struct iphdr *iph = oldskb->nh.iph;
 	struct tcphdr _otcph, *oth, *tcph;
 	__be16 tmp_port;
 	__be32 tmp_addr;
@@ -54,7 +53,7 @@ static void send_reset(struct sk_buff *oldskb, int hook)
 	if (oldskb->nh.iph->frag_off & htons(IP_OFFSET))
 		return;
 
-	oth = skb_header_pointer(oldskb, oldskb->nh.iph->ihl * 4,
+	oth = skb_header_pointer(oldskb, ip_hdrlen(oldskb),
 				 sizeof(_otcph), &_otcph);
 	if (oth == NULL)
 		return;
@@ -64,7 +63,7 @@ static void send_reset(struct sk_buff *oldskb, int hook)
 		return;
 
 	/* Check checksum */
-	if (nf_ip_checksum(oldskb, hook, iph->ihl * 4, IPPROTO_TCP))
+	if (nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), IPPROTO_TCP))
 		return;
 
 	/* We need a linear, writeable skb.  We also need to expand
@@ -84,7 +83,7 @@ static void send_reset(struct sk_buff *oldskb, int hook)
 	skb_shinfo(nskb)->gso_segs = 0;
 	skb_shinfo(nskb)->gso_type = 0;
 
-	tcph = (struct tcphdr *)((u_int32_t*)nskb->nh.iph + nskb->nh.iph->ihl);
+	tcph = (struct tcphdr *)(skb_network_header(nskb) + ip_hdrlen(nskb));
 
 	/* Swap source and dest */
 	tmp_addr = nskb->nh.iph->saddr;
@@ -96,7 +95,7 @@ static void send_reset(struct sk_buff *oldskb, int hook)
 
 	/* Truncate to length (no data) */
 	tcph->doff = sizeof(struct tcphdr)/4;
-	skb_trim(nskb, nskb->nh.iph->ihl*4 + sizeof(struct tcphdr));
+	skb_trim(nskb, ip_hdrlen(nskb) + sizeof(struct tcphdr));
 	nskb->nh.iph->tot_len = htons(nskb->len);
 
 	if (tcph->ack) {
@@ -105,9 +104,9 @@ static void send_reset(struct sk_buff *oldskb, int hook)
 		tcph->ack_seq = 0;
 	} else {
 		needs_ack = 1;
-		tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin
-				      + oldskb->len - oldskb->nh.iph->ihl*4
-				      - (oth->doff<<2));
+		tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin +
+				      oldskb->len - ip_hdrlen(oldskb) -
+				      (oth->doff << 2));
 		tcph->seq = 0;
 	}
 
@@ -149,7 +148,7 @@ static void send_reset(struct sk_buff *oldskb, int hook)
 
 	/* Adjust IP checksum */
 	nskb->nh.iph->check = 0;
-	nskb->nh.iph->check = ip_fast_csum((unsigned char *)nskb->nh.iph,
+	nskb->nh.iph->check = ip_fast_csum(skb_network_header(nskb),
 					   nskb->nh.iph->ihl);
 
 	/* "Never happens" */
@@ -182,7 +181,7 @@ static unsigned int reject(struct sk_buff **pskb,
 
 	/* Our naive response construction doesn't deal with IP
 	   options, and probably shouldn't try. */
-	if ((*pskb)->nh.iph->ihl<<2 != sizeof(struct iphdr))
+	if (ip_hdrlen(*pskb) != sizeof(struct iphdr))
 		return NF_DROP;
 
 	/* WARNING: This code causes reentry within iptables.
diff --git a/net/ipv4/netfilter/ipt_ecn.c b/net/ipv4/netfilter/ipt_ecn.c
index 37508b2..b8ade3c 100644
--- a/net/ipv4/netfilter/ipt_ecn.c
+++ b/net/ipv4/netfilter/ipt_ecn.c
@@ -11,6 +11,7 @@
 
 #include <linux/in.h>
 #include <linux/ip.h>
+#include <net/ip.h>
 #include <linux/module.h>
 #include <linux/skbuff.h>
 #include <linux/tcp.h>
@@ -38,8 +39,7 @@ static inline int match_tcp(const struct sk_buff *skb,
 	/* In practice, TCP match does this, so can't fail.  But let's
 	 * be good citizens.
 	 */
-	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) {
 		*hotdrop = 0;
 		return 0;
diff --git a/net/ipv4/netfilter/iptable_filter.c b/net/ipv4/netfilter/iptable_filter.c
index d1d61e9..4272890 100644
--- a/net/ipv4/netfilter/iptable_filter.c
+++ b/net/ipv4/netfilter/iptable_filter.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/netfilter_ipv4/ip_tables.h>
+#include <net/ip.h>
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
@@ -102,7 +103,7 @@ ipt_local_out_hook(unsigned int hook,
 {
 	/* root is playing with raw sockets. */
 	if ((*pskb)->len < sizeof(struct iphdr)
-	    || (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr)) {
+	    || ip_hdrlen(*pskb) < sizeof(struct iphdr)) {
 		if (net_ratelimit())
 			printk("ipt_hook: happy cracking.\n");
 		return NF_ACCEPT;
diff --git a/net/ipv4/netfilter/iptable_mangle.c b/net/ipv4/netfilter/iptable_mangle.c
index 98b66ef..6cc3245 100644
--- a/net/ipv4/netfilter/iptable_mangle.c
+++ b/net/ipv4/netfilter/iptable_mangle.c
@@ -17,6 +17,7 @@
 #include <net/sock.h>
 #include <net/route.h>
 #include <linux/ip.h>
+#include <net/ip.h>
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
@@ -136,7 +137,7 @@ ipt_local_hook(unsigned int hook,
 
 	/* root is playing with raw sockets. */
 	if ((*pskb)->len < sizeof(struct iphdr)
-	    || (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr)) {
+	    || ip_hdrlen(*pskb) < sizeof(struct iphdr)) {
 		if (net_ratelimit())
 			printk("ipt_hook: happy cracking.\n");
 		return NF_ACCEPT;
diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
index 7cebbff..fa14eb7 100644
--- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
+++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
@@ -105,7 +105,7 @@ ipv4_prepare(struct sk_buff **pskb, unsigned int hooknum, unsigned int *dataoff,
 		return -NF_DROP;
 	}
 
-	*dataoff = skb_network_offset(*pskb) + (*pskb)->nh.iph->ihl * 4;
+	*dataoff = skb_network_offset(*pskb) + ip_hdrlen(*pskb);
 	*protonum = (*pskb)->nh.iph->protocol;
 
 	return NF_ACCEPT;
@@ -151,8 +151,8 @@ static unsigned int ipv4_conntrack_help(unsigned int hooknum,
 	if (!help || !help->helper)
 		return NF_ACCEPT;
 
-	return help->helper->help(pskb, (skb_network_offset(*pskb) +
-					 (*pskb)->nh.iph->ihl * 4),
+	return help->helper->help(pskb,
+				  skb_network_offset(*pskb) + ip_hdrlen(*pskb),
 				  ct, ctinfo);
 }
 
@@ -198,7 +198,7 @@ static unsigned int ipv4_conntrack_local(unsigned int hooknum,
 {
 	/* root is playing with raw sockets. */
 	if ((*pskb)->len < sizeof(struct iphdr)
-	    || (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr)) {
+	    || ip_hdrlen(*pskb) < sizeof(struct iphdr)) {
 		if (net_ratelimit())
 			printk("ipt_hook: happy cracking.\n");
 		return NF_ACCEPT;
diff --git a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
index 5fd1e53..e090e92 100644
--- a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
+++ b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
@@ -158,7 +158,7 @@ icmp_error_message(struct sk_buff *skb,
 	NF_CT_ASSERT(skb->nfct == NULL);
 
 	/* Not enough header? */
-	inside = skb_header_pointer(skb, skb->nh.iph->ihl*4, sizeof(_in), &_in);
+	inside = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_in), &_in);
 	if (inside == NULL)
 		return -NF_ACCEPT;
 
@@ -172,7 +172,7 @@ icmp_error_message(struct sk_buff *skb,
 	/* rcu_read_lock()ed by nf_hook_slow */
 	innerproto = __nf_ct_l4proto_find(PF_INET, inside->ip.protocol);
 
-	dataoff = skb->nh.iph->ihl*4 + sizeof(inside->icmp);
+	dataoff = ip_hdrlen(skb) + sizeof(inside->icmp);
 	/* Are they talking about one of our connections? */
 	if (!nf_ct_get_tuple(skb, dataoff, dataoff + inside->ip.ihl*4, PF_INET,
 			     inside->ip.protocol, &origtuple,
@@ -227,7 +227,7 @@ icmp_error(struct sk_buff *skb, unsigned int dataoff,
 	struct icmphdr _ih, *icmph;
 
 	/* Not enough header? */
-	icmph = skb_header_pointer(skb, skb->nh.iph->ihl*4, sizeof(_ih), &_ih);
+	icmph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_ih), &_ih);
 	if (icmph == NULL) {
 		if (LOG_INVALID(IPPROTO_ICMP))
 			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
diff --git a/net/ipv4/netfilter/nf_nat_core.c b/net/ipv4/netfilter/nf_nat_core.c
index 452e9d3..ea02f00 100644
--- a/net/ipv4/netfilter/nf_nat_core.c
+++ b/net/ipv4/netfilter/nf_nat_core.c
@@ -431,7 +431,7 @@ int nf_nat_icmp_reply_translation(struct nf_conn *ct,
 	} *inside;
 	struct nf_conntrack_l4proto *l4proto;
 	struct nf_conntrack_tuple inner, target;
-	int hdrlen = (*pskb)->nh.iph->ihl * 4;
+	int hdrlen = ip_hdrlen(*pskb);
 	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
 	unsigned long statusbit;
 	enum nf_nat_manip_type manip = HOOK2MANIP(hooknum);
@@ -439,7 +439,7 @@ int nf_nat_icmp_reply_translation(struct nf_conn *ct,
 	if (!skb_make_writable(pskb, hdrlen + sizeof(*inside)))
 		return 0;
 
-	inside = (void *)(*pskb)->data + (*pskb)->nh.iph->ihl*4;
+	inside = (void *)(*pskb)->data + ip_hdrlen(*pskb);
 
 	/* We're actually going to mangle it beyond trivial checksum
 	   adjustment, so make sure the current checksum is correct. */
@@ -469,9 +469,9 @@ int nf_nat_icmp_reply_translation(struct nf_conn *ct,
 	l4proto = __nf_ct_l4proto_find(PF_INET, inside->ip.protocol);
 
 	if (!nf_ct_get_tuple(*pskb,
-			     (*pskb)->nh.iph->ihl*4 + sizeof(struct icmphdr),
-			     (*pskb)->nh.iph->ihl*4 +
-			     sizeof(struct icmphdr) + inside->ip.ihl*4,
+			     ip_hdrlen(*pskb) + sizeof(struct icmphdr),
+			     (ip_hdrlen(*pskb) +
+			      sizeof(struct icmphdr) + inside->ip.ihl * 4),
 			     (u_int16_t)AF_INET,
 			     inside->ip.protocol,
 			     &inner, l3proto, l4proto))
@@ -483,14 +483,14 @@ int nf_nat_icmp_reply_translation(struct nf_conn *ct,
 	   packet: PREROUTING (DST manip), routing produces ICMP, goes
 	   through POSTROUTING (which must correct the DST manip). */
 	if (!manip_pkt(inside->ip.protocol, pskb,
-		       (*pskb)->nh.iph->ihl*4 + sizeof(inside->icmp),
+		       ip_hdrlen(*pskb) + sizeof(inside->icmp),
 		       &ct->tuplehash[!dir].tuple,
 		       !manip))
 		return 0;
 
 	if ((*pskb)->ip_summed != CHECKSUM_PARTIAL) {
 		/* Reloading "inside" here since manip_pkt inner. */
-		inside = (void *)(*pskb)->data + (*pskb)->nh.iph->ihl*4;
+		inside = (void *)(*pskb)->data + ip_hdrlen(*pskb);
 		inside->icmp.checksum = 0;
 		inside->icmp.checksum =
 			csum_fold(skb_checksum(*pskb, hdrlen,
diff --git a/net/ipv4/netfilter/nf_nat_h323.c b/net/ipv4/netfilter/nf_nat_h323.c
index 9cbf3f9..2eb3832 100644
--- a/net/ipv4/netfilter/nf_nat_h323.c
+++ b/net/ipv4/netfilter/nf_nat_h323.c
@@ -55,11 +55,11 @@ static int set_addr(struct sk_buff **pskb,
 		}
 
 		/* Relocate data pointer */
-		th = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl * 4,
+		th = skb_header_pointer(*pskb, ip_hdrlen(*pskb),
 					sizeof(_tcph), &_tcph);
 		if (th == NULL)
 			return -1;
-		*data = (*pskb)->data + (*pskb)->nh.iph->ihl * 4 +
+		*data = (*pskb)->data + ip_hdrlen(*pskb) +
 		    th->doff * 4 + dataoff;
 	} else {
 		if (!nf_nat_mangle_udp_packet(pskb, ct, ctinfo,
@@ -73,8 +73,8 @@ static int set_addr(struct sk_buff **pskb,
 		/* nf_nat_mangle_udp_packet uses skb_make_writable() to copy
 		 * or pull everything in a linear buffer, so we can safely
 		 * use the skb pointers now */
-		*data = (*pskb)->data + (*pskb)->nh.iph->ihl * 4 +
-		    sizeof(struct udphdr);
+		*data = ((*pskb)->data + ip_hdrlen(*pskb) +
+			 sizeof(struct udphdr));
 	}
 
 	return 0;
diff --git a/net/ipv4/netfilter/nf_nat_helper.c b/net/ipv4/netfilter/nf_nat_helper.c
index 49a90c3..723302a 100644
--- a/net/ipv4/netfilter/nf_nat_helper.c
+++ b/net/ipv4/netfilter/nf_nat_helper.c
@@ -190,7 +190,7 @@ nf_nat_mangle_tcp_packet(struct sk_buff **pskb,
 				    (int)rep_len - (int)match_len,
 				    ct, ctinfo);
 		/* Tell TCP window tracking about seq change */
-		nf_conntrack_tcp_update(*pskb, (*pskb)->nh.iph->ihl*4,
+		nf_conntrack_tcp_update(*pskb, ip_hdrlen(*pskb),
 					ct, CTINFO2DIR(ctinfo));
 	}
 	return 1;
@@ -318,8 +318,8 @@ nf_nat_sack_adjust(struct sk_buff **pskb,
 	unsigned int dir, optoff, optend;
 	struct nf_conn_nat *nat = nfct_nat(ct);
 
-	optoff = (*pskb)->nh.iph->ihl*4 + sizeof(struct tcphdr);
-	optend = (*pskb)->nh.iph->ihl*4 + tcph->doff*4;
+	optoff = ip_hdrlen(*pskb) + sizeof(struct tcphdr);
+	optend = ip_hdrlen(*pskb) + tcph->doff * 4;
 
 	if (!skb_make_writable(pskb, optend))
 		return 0;
@@ -371,10 +371,10 @@ nf_nat_seq_adjust(struct sk_buff **pskb,
 	this_way = &nat->info.seq[dir];
 	other_way = &nat->info.seq[!dir];
 
-	if (!skb_make_writable(pskb, (*pskb)->nh.iph->ihl*4+sizeof(*tcph)))
+	if (!skb_make_writable(pskb, ip_hdrlen(*pskb) + sizeof(*tcph)))
 		return 0;
 
-	tcph = (void *)(*pskb)->data + (*pskb)->nh.iph->ihl*4;
+	tcph = (void *)(*pskb)->data + ip_hdrlen(*pskb);
 	if (after(ntohl(tcph->seq), this_way->correction_pos))
 		newseq = htonl(ntohl(tcph->seq) + this_way->offset_after);
 	else
@@ -399,7 +399,7 @@ nf_nat_seq_adjust(struct sk_buff **pskb,
 	if (!nf_nat_sack_adjust(pskb, tcph, ct, ctinfo))
 		return 0;
 
-	nf_conntrack_tcp_update(*pskb, (*pskb)->nh.iph->ihl*4, ct, dir);
+	nf_conntrack_tcp_update(*pskb, ip_hdrlen(*pskb), ct, dir);
 
 	return 1;
 }
diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c
index b12cd7c..bfd88e4 100644
--- a/net/ipv4/netfilter/nf_nat_sip.c
+++ b/net/ipv4/netfilter/nf_nat_sip.c
@@ -11,6 +11,7 @@
 #include <linux/module.h>
 #include <linux/skbuff.h>
 #include <linux/ip.h>
+#include <net/ip.h>
 #include <linux/udp.h>
 
 #include <net/netfilter/nf_nat.h>
@@ -92,7 +93,7 @@ static int map_sip_addr(struct sk_buff **pskb, enum ip_conntrack_info ctinfo,
 	if (!nf_nat_mangle_udp_packet(pskb, ct, ctinfo,
 				      matchoff, matchlen, addr, addrlen))
 		return 0;
-	*dptr = (*pskb)->data + (*pskb)->nh.iph->ihl*4 + sizeof(struct udphdr);
+	*dptr = (*pskb)->data + ip_hdrlen(*pskb) + sizeof(struct udphdr);
 	return 1;
 
 }
@@ -106,7 +107,7 @@ static unsigned int ip_nat_sip(struct sk_buff **pskb,
 	struct addr_map map;
 	int dataoff, datalen;
 
-	dataoff = (*pskb)->nh.iph->ihl*4 + sizeof(struct udphdr);
+	dataoff = ip_hdrlen(*pskb) + sizeof(struct udphdr);
 	datalen = (*pskb)->len - dataoff;
 	if (datalen < sizeof("SIP/2.0") - 1)
 		return NF_DROP;
@@ -155,7 +156,7 @@ static unsigned int mangle_sip_packet(struct sk_buff **pskb,
 		return 0;
 
 	/* We need to reload this. Thanks Patrick. */
-	*dptr = (*pskb)->data + (*pskb)->nh.iph->ihl*4 + sizeof(struct udphdr);
+	*dptr = (*pskb)->data + ip_hdrlen(*pskb) + sizeof(struct udphdr);
 	return 1;
 }
 
@@ -168,7 +169,7 @@ static int mangle_content_len(struct sk_buff **pskb,
 	char buffer[sizeof("65536")];
 	int bufflen;
 
-	dataoff = (*pskb)->nh.iph->ihl*4 + sizeof(struct udphdr);
+	dataoff = ip_hdrlen(*pskb) + sizeof(struct udphdr);
 
 	/* Get actual SDP lenght */
 	if (ct_sip_get_info(ct, dptr, (*pskb)->len - dataoff, &matchoff,
@@ -200,7 +201,7 @@ static unsigned int mangle_sdp(struct sk_buff **pskb,
 	char buffer[sizeof("nnn.nnn.nnn.nnn")];
 	unsigned int dataoff, bufflen;
 
-	dataoff = (*pskb)->nh.iph->ihl*4 + sizeof(struct udphdr);
+	dataoff = ip_hdrlen(*pskb) + sizeof(struct udphdr);
 
 	/* Mangle owner and contact info. */
 	bufflen = sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(newip));
diff --git a/net/ipv4/netfilter/nf_nat_standalone.c b/net/ipv4/netfilter/nf_nat_standalone.c
index 15aa3db..61ca272 100644
--- a/net/ipv4/netfilter/nf_nat_standalone.c
+++ b/net/ipv4/netfilter/nf_nat_standalone.c
@@ -101,8 +101,7 @@ nf_nat_fn(unsigned int hooknum,
 		if ((*pskb)->nh.iph->protocol == IPPROTO_ICMP) {
 			struct icmphdr _hdr, *hp;
 
-			hp = skb_header_pointer(*pskb,
-						(*pskb)->nh.iph->ihl*4,
+			hp = skb_header_pointer(*pskb, ip_hdrlen(*pskb),
 						sizeof(_hdr), &_hdr);
 			if (hp != NULL &&
 			    hp->type == ICMP_REDIRECT)
@@ -203,7 +202,7 @@ nf_nat_out(unsigned int hooknum,
 
 	/* root is playing with raw sockets. */
 	if ((*pskb)->len < sizeof(struct iphdr) ||
-	    (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr))
+	    ip_hdrlen(*pskb) < sizeof(struct iphdr))
 		return NF_ACCEPT;
 
 	ret = nf_nat_fn(hooknum, pskb, in, out, okfn);
@@ -236,7 +235,7 @@ nf_nat_local_fn(unsigned int hooknum,
 
 	/* root is playing with raw sockets. */
 	if ((*pskb)->len < sizeof(struct iphdr) ||
-	    (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr))
+	    ip_hdrlen(*pskb) < sizeof(struct iphdr))
 		return NF_ACCEPT;
 
 	ret = nf_nat_fn(hooknum, pskb, in, out, okfn);