[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>

drivers/net/bnx2.c

@@ -4527,7 +4527,7 @@ bnx2_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		if (skb->h.th->doff > 5) {
 			tcp_opt_len = (skb->h.th->doff - 5) << 2;
 		}
-		ip_tcp_len = (skb->nh.iph->ihl << 2) + sizeof(struct tcphdr);
+		ip_tcp_len = ip_hdrlen(skb) + sizeof(struct tcphdr);
 
 		skb->nh.iph->check = 0;
 		skb->nh.iph->tot_len = htons(mss + ip_tcp_len + tcp_opt_len);

drivers/net/ehea/ehea_main.c

@@ -1263,7 +1263,7 @@ static inline void write_ip_start_end(struct ehea_swqe *swqe,
 				      const struct sk_buff *skb)
 {
 	swqe->ip_start = (u8)(((u64)skb->nh.iph) - ((u64)skb->data));
-	swqe->ip_end = (u8)(swqe->ip_start + skb->nh.iph->ihl * 4 - 1);
+	swqe->ip_end = (u8)(swqe->ip_start + ip_hdrlen(skb) - 1);
 }
 
 static inline void write_tcp_offset_end(struct ehea_swqe *swqe,
@@ -1300,7 +1300,7 @@ static void write_swqe2_TSO(struct sk_buff *skb,
 	/* copy only eth/ip/tcp headers to immediate data and
 	 * the rest of skb->data to sg1entry
 	 */
-	headersize = ETH_HLEN + (skb->nh.iph->ihl * 4) + (skb->h.th->doff * 4);
+	headersize = ETH_HLEN + ip_hdrlen(skb) + (skb->h.th->doff * 4);
 
 	skb_data_size = skb->len - skb->data_len;
 

drivers/net/netxen/netxen_nic_hw.c

@@ -35,6 +35,8 @@
 #include "netxen_nic_hw.h"
 #include "netxen_nic_phan_reg.h"
 
+#include <net/ip.h>
+
 /*  PCI Windowing for DDR regions.  */
 
 #define ADDR_IN_RANGE(addr, low, high)	\
@@ -371,9 +373,9 @@ void netxen_tso_check(struct netxen_adapter *adapter,
 		      struct cmd_desc_type0 *desc, struct sk_buff *skb)
 {
 	if (desc->mss) {
-		desc->total_hdr_length = sizeof(struct ethhdr) +
-		    ((skb->nh.iph)->ihl * sizeof(u32)) +
-		    ((skb->h.th)->doff * sizeof(u32));
+		desc->total_hdr_length = (sizeof(struct ethhdr) +
+					  ip_hdrlen(skb) +
+					  skb->h.th->doff * 4);
 		netxen_set_cmd_desc_opcode(desc, TX_TCP_LSO);
 	} else if (skb->ip_summed == CHECKSUM_PARTIAL) {
 		if (skb->nh.iph->protocol == IPPROTO_TCP) {

drivers/net/netxen/netxen_nic_main.c

@@ -41,6 +41,7 @@
 
 #include <linux/dma-mapping.h>
 #include <linux/vmalloc.h>
+#include <net/ip.h>
 
 MODULE_DESCRIPTION("NetXen Multi port (1/10) Gigabit Network Driver");
 MODULE_LICENSE("GPL");
@@ -778,9 +779,8 @@ static int netxen_nic_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
 		if (skb_shinfo(skb)->gso_size > 0) {
 
 			no_of_desc++;
-			if (((skb->nh.iph)->ihl * sizeof(u32)) +
-			    ((skb->h.th)->doff * sizeof(u32)) +
-			    sizeof(struct ethhdr) >
+			if ((ip_hdrlen(skb) + skb->h.th->doff * 4 +
+			     sizeof(struct ethhdr)) >
 			    (sizeof(struct cmd_desc_type0) - 2)) {
 				no_of_desc++;
 			}

drivers/net/sky2.c

@@ -32,6 +32,7 @@
 #include <linux/ethtool.h>
 #include <linux/pci.h>
 #include <linux/ip.h>
+#include <net/ip.h>
 #include <linux/tcp.h>
 #include <linux/in.h>
 #include <linux/delay.h>
@@ -1392,7 +1393,7 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
 	mss = skb_shinfo(skb)->gso_size;
 	if (mss != 0) {
 		mss += ((skb->h.th->doff - 5) * 4);	/* TCP options */
-		mss += (skb->nh.iph->ihl * 4) + sizeof(struct tcphdr);
+		mss += ip_hdrlen(skb) + sizeof(struct tcphdr);
 		mss += ETH_HLEN;
 
 		if (mss != sky2->tx_last_mss) {

drivers/net/tg3.c

@@ -40,6 +40,7 @@
 #include <linux/dma-mapping.h>
 
 #include <net/checksum.h>
+#include <net/ip.h>
 
 #include <asm/system.h>
 #include <asm/io.h>
@@ -3909,8 +3910,7 @@ static int tg3_start_xmit(struct sk_buff *skb, struct net_device *dev)
 			mss |= (skb_headlen(skb) - ETH_HLEN) << 9;
 		else {
 			tcp_opt_len = ((skb->h.th->doff - 5) * 4);
-			ip_tcp_len = (skb->nh.iph->ihl * 4) +
-				     sizeof(struct tcphdr);
+			ip_tcp_len = ip_hdrlen(skb) + sizeof(struct tcphdr);
 
 			skb->nh.iph->check = 0;
 			skb->nh.iph->tot_len = htons(mss + ip_tcp_len +
@@ -4064,7 +4064,7 @@ static int tg3_start_xmit_dma_bug(struct sk_buff *skb, struct net_device *dev)
 		}
 
 		tcp_opt_len = ((skb->h.th->doff - 5) * 4);
-		ip_tcp_len = (skb->nh.iph->ihl * 4) + sizeof(struct tcphdr);
+		ip_tcp_len = ip_hdrlen(skb) + sizeof(struct tcphdr);
 
 		hdr_len = ip_tcp_len + tcp_opt_len;
 		if (unlikely((ETH_HLEN + hdr_len) > 80) &&

drivers/s390/net/qeth_eddp.c

@@ -473,9 +473,11 @@ qeth_eddp_fill_context_tcp(struct qeth_eddp_context *ctx,
 	QETH_DBF_TEXT(trace, 5, "eddpficx");
 	/* create our segmentation headers and copy original headers */
 	if (skb->protocol == htons(ETH_P_IP))
-		eddp = qeth_eddp_create_eddp_data(qhdr, (u8 *)skb->nh.iph,
-				skb->nh.iph->ihl*4,
-				(u8 *)skb->h.th, skb->h.th->doff*4);
+		eddp = qeth_eddp_create_eddp_data(qhdr,
+						  skb_network_header(skb),
+						  ip_hdrlen(skb),
+						  skb->h.raw,
+						  skb->h.th->doff * 4);
 	else
 		eddp = qeth_eddp_create_eddp_data(qhdr, (u8 *)skb->nh.ipv6h,
 				sizeof(struct ipv6hdr),
@@ -590,8 +592,9 @@ qeth_eddp_create_context_tcp(struct qeth_card *card, struct sk_buff *skb,
 	QETH_DBF_TEXT(trace, 5, "creddpct");
 	if (skb->protocol == htons(ETH_P_IP))
 		ctx = qeth_eddp_create_context_generic(card, skb,
-			sizeof(struct qeth_hdr) + skb->nh.iph->ihl*4 +
-			skb->h.th->doff*4);
+						       (sizeof(struct qeth_hdr) +
+						        ip_hdrlen(skb) +
+							skb->h.th->doff * 4));
 	else if (skb->protocol == htons(ETH_P_IPV6))
 		ctx = qeth_eddp_create_context_generic(card, skb,
 			sizeof(struct qeth_hdr) + sizeof(struct ipv6hdr) +

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 *);

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)

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;

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;

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;
 

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;

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;
 

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)

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);

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 */

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);

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;