[SK_BUFF]: Introduce skb_network_offset()

For the quite common 'skb->nh.raw - skb->data' sequence.

Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/isdn/i4l/isdn_net.c

···
 	if (!skb)
 		return;
 	if (lp->p_encap == ISDN_NET_ENCAP_ETHER) {
-		int pullsize = (ulong)skb->nh.raw - (ulong)skb->data - ETH_HLEN;
+		const int pullsize = skb_network_offset(skb) - ETH_HLEN;
 		if (pullsize > 0) {
 			printk(KERN_DEBUG "isdn_net: Pull junk %d\n", pullsize);
 			skb_pull(skb, pullsize);

drivers/net/atl1/atl1_main.c

···
 			    ~csum_tcpudp_magic(skb->nh.iph->saddr,
 					       skb->nh.iph->daddr, 0,
 					       IPPROTO_TCP, 0);
-			ipofst = skb->nh.raw - skb->data;
+			ipofst = skb_network_offset(skb);
 			if (ipofst != ENET_HEADER_SIZE) /* 802.3 frame */
 				tso->tsopl |= 1 << TSO_PARAM_ETHTYPE_SHIFT;
 

drivers/net/chelsio/sge.c

···
 
 		++st->tx_tso;
 
-		eth_type = skb->nh.raw - skb->data == ETH_HLEN ?
+		eth_type = skb_network_offset(skb) == ETH_HLEN ?
 			CPL_ETH_II : CPL_ETH_II_VLAN;
 
 		hdr = (struct cpl_tx_pkt_lso *)skb_push(skb, sizeof(*hdr));

drivers/net/cxgb3/sge.c

···
 		d->flit[2] = 0;
 		cntrl |= V_TXPKT_OPCODE(CPL_TX_PKT_LSO);
 		hdr->cntrl = htonl(cntrl);
-		eth_type = skb->nh.raw - skb->data == ETH_HLEN ?
+		eth_type = skb_network_offset(skb) == ETH_HLEN ?
 		    CPL_ETH_II : CPL_ETH_II_VLAN;
 		tso_info |= V_LSO_ETH_TYPE(eth_type) |
 		    V_LSO_IPHDR_WORDS(skb->nh.iph->ihl) |

drivers/net/e1000/e1000_main.c

···
 						 0);
 			ipcse = 0;
 		}
-		ipcss = skb->nh.raw - skb->data;
+		ipcss = skb_network_offset(skb);
 		ipcso = (void *)&(skb->nh.iph->check) - (void *)skb->data;
 		tucss = skb->h.raw - skb->data;
 		tucso = (void *)&(skb->h.th->check) - (void *)skb->data;

drivers/net/gianfar.c

···
 	 * frame (skb->data) and the start of the IP hdr.
 	 * l4os is the distance between the start of the
 	 * l3 hdr and the l4 hdr */
-	fcb->l3os = (u16)(skb->nh.raw - skb->data - GMAC_FCB_LEN);
+	fcb->l3os = (u16)(skb_network_offset(skb) - GMAC_FCB_LEN);
 	fcb->l4os = (u16)(skb->h.raw - skb->nh.raw);
 
 	fcb->flags = flags;

drivers/net/ixgb/ixgb_main.c

···
 		skb->h.th->check = ~csum_tcpudp_magic(skb->nh.iph->saddr,
 						      skb->nh.iph->daddr,
 						      0, IPPROTO_TCP, 0);
-		ipcss = skb->nh.raw - skb->data;
+		ipcss = skb_network_offset(skb);
 		ipcso = (void *)&(skb->nh.iph->check) - (void *)skb->data;
 		ipcse = skb->h.raw - skb->data - 1;
 		tucss = skb->h.raw - skb->data;

drivers/net/netxen/netxen_nic_hw.c

···
 	}
 	adapter->stats.xmitcsummed++;
 	desc->tcp_hdr_offset = skb->h.raw - skb->data;
-	desc->ip_hdr_offset = skb->nh.raw - skb->data;
+	desc->ip_hdr_offset = skb_network_offset(skb);
 }
 
 int netxen_is_flash_supported(struct netxen_adapter *adapter)

include/linux/skbuff.h

···
 	skb->nh.raw = skb->data;
 }
 
+static inline int skb_network_offset(const struct sk_buff *skb)
+{
+	return skb->nh.raw - skb->data;
+}
+
 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
 {
 	return skb->mac.raw;

net/ax25/ax25_out.c

···
 
 			if (ka9qfrag == 1) {
 				skb_reserve(skbn, frontlen + 2);
-				skbn->nh.raw = skbn->data + (skb->nh.raw - skb->data);
+				skbn->nh.raw = skbn->data + skb_network_offset(skb);
 				memcpy(skb_put(skbn, len), skb->data, len);
 				p = skb_push(skbn, 2);
 
···
 				}
 			} else {
 				skb_reserve(skbn, frontlen + 1);
-				skbn->nh.raw = skbn->data + (skb->nh.raw - skb->data);
+				skbn->nh.raw = skbn->data + skb_network_offset(skb);
 				memcpy(skb_put(skbn, len), skb->data, len);
 				p = skb_push(skbn, 1);
 				*p = AX25_P_TEXT;

net/core/neighbour.c

···
 {
 	struct net_device *dev = skb->dev;
 
-	__skb_pull(skb, skb->nh.raw - skb->data);
+	__skb_pull(skb, skb_network_offset(skb));
 
 	if (dev->hard_header &&
 	    dev->hard_header(skb, dev, ntohs(skb->protocol), NULL, NULL,
···
 	if (!dst || !(neigh = dst->neighbour))
 		goto discard;
 
-	__skb_pull(skb, skb->nh.raw - skb->data);
+	__skb_pull(skb, skb_network_offset(skb));
 
 	if (!neigh_event_send(neigh, skb)) {
 		int err;
···
 	struct neighbour *neigh = dst->neighbour;
 	struct net_device *dev = neigh->dev;
 
-	__skb_pull(skb, skb->nh.raw - skb->data);
+	__skb_pull(skb, skb_network_offset(skb));
 
 	read_lock_bh(&neigh->lock);
 	err = dev->hard_header(skb, dev, ntohs(skb->protocol),

net/ipv4/ip_output.c

···
 static int ip_dev_loopback_xmit(struct sk_buff *newskb)
 {
 	skb_reset_mac_header(newskb);
-	__skb_pull(newskb, newskb->nh.raw - newskb->data);
+	__skb_pull(newskb, skb_network_offset(newskb));
 	newskb->pkt_type = PACKET_LOOPBACK;
 	newskb->ip_summed = CHECKSUM_UNNECESSARY;
 	BUG_TRAP(newskb->dst);
···
 
 	/* move skb->data to ip header from ext header */
 	if (skb->data < skb->nh.raw)
-		__skb_pull(skb, skb->nh.raw - skb->data);
+		__skb_pull(skb, skb_network_offset(skb));
 	while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
 		__skb_pull(tmp_skb, skb->h.raw - skb->nh.raw);
 		*tail_skb = tmp_skb;

net/ipv6/icmp.c

···
 {
 	u8 _optval, *op;
 
-	offset += skb->nh.raw - skb->data;
+	offset += skb_network_offset(skb);
 	op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
 	if (op == NULL)
 		return 1;
···
 		tclass = 0;
 
 	msg.skb = skb;
-	msg.offset = skb->nh.raw - skb->data;
+	msg.offset = skb_network_offset(skb);
 	msg.type = type;
 
 	len = skb->len - msg.offset;

net/ipv6/ip6_output.c

···
 static int ip6_dev_loopback_xmit(struct sk_buff *newskb)
 {
 	skb_reset_mac_header(newskb);
-	__skb_pull(newskb, newskb->nh.raw - newskb->data);
+	__skb_pull(newskb, skb_network_offset(newskb));
 	newskb->pkt_type = PACKET_LOOPBACK;
 	newskb->ip_summed = CHECKSUM_UNNECESSARY;
 	BUG_TRAP(newskb->dst);
···
 
 	/* move skb->data to ip header from ext header */
 	if (skb->data < skb->nh.raw)
-		__skb_pull(skb, skb->nh.raw - skb->data);
+		__skb_pull(skb, skb_network_offset(skb));
 	while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
 		__skb_pull(tmp_skb, skb->h.raw - skb->nh.raw);
 		*tail_skb = tmp_skb;

net/netfilter/nf_conntrack_core.c

···
 	struct nf_conntrack_tuple_hash *h;
 	struct nf_conn *ct;
 
-	if (!nf_ct_get_tuple(skb, (unsigned int)(skb->nh.raw - skb->data),
+	if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
 			     dataoff, l3num, protonum, &tuple, l3proto,
 			     l4proto)) {
 		DEBUGP("resolve_normal_ct: Can't get tuple\n");
···
 	if (do_acct) {
 		ct->counters[CTINFO2DIR(ctinfo)].packets++;
 		ct->counters[CTINFO2DIR(ctinfo)].bytes +=
-			skb->len - (unsigned int)(skb->nh.raw - skb->data);
+			skb->len - skb_network_offset(skb);
 
 		if ((ct->counters[CTINFO2DIR(ctinfo)].packets & 0x80000000)
 		    || (ct->counters[CTINFO2DIR(ctinfo)].bytes & 0x80000000))

net/packet/af_packet.c

···
 			skb_push(skb, skb->data - skb_mac_header(skb));
 		else if (skb->pkt_type == PACKET_OUTGOING) {
 			/* Special case: outgoing packets have ll header at head */
-			skb_pull(skb, skb->nh.raw - skb->data);
+			skb_pull(skb, skb_network_offset(skb));
 		}
 	}
 
···
 			skb_push(skb, skb->data - skb_mac_header(skb));
 		else if (skb->pkt_type == PACKET_OUTGOING) {
 			/* Special case: outgoing packets have ll header at head */
-			skb_pull(skb, skb->nh.raw - skb->data);
+			skb_pull(skb, skb_network_offset(skb));
 		}
 	}
 
···
 	if (sk->sk_type == SOCK_DGRAM) {
 		macoff = netoff = TPACKET_ALIGN(TPACKET_HDRLEN) + 16;
 	} else {
-		unsigned maclen = skb->nh.raw - skb->data;
+		unsigned maclen = skb_network_offset(skb);
 		netoff = TPACKET_ALIGN(TPACKET_HDRLEN + (maclen < 16 ? 16 : maclen));
 		macoff = netoff - maclen;
 	}
···
 		aux.tp_len = PACKET_SKB_CB(skb)->origlen;
 		aux.tp_snaplen = skb->len;
 		aux.tp_mac = 0;
-		aux.tp_net = skb->nh.raw - skb->data;
+		aux.tp_net = skb_network_offset(skb);
 
 		put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
 	}

net/sched/sch_teql.c

···
 			nores = 1;
 			break;
 		}
-		__skb_pull(skb, skb->nh.raw - skb->data);
+		__skb_pull(skb, skb_network_offset(skb));
 	} while ((q = NEXT_SLAVE(q)) != start);
 
 	if (nores && skb_res == NULL) {

security/selinux/hooks.c

···
 	int offset, ihlen, ret = -EINVAL;
 	struct iphdr _iph, *ih;
 
-	offset = skb->nh.raw - skb->data;
+	offset = skb_network_offset(skb);
 	ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
 	if (ih == NULL)
 		goto out;
···
 	int ret = -EINVAL, offset;
 	struct ipv6hdr _ipv6h, *ip6;
 
-	offset = skb->nh.raw - skb->data;
+	offset = skb_network_offset(skb);
 	ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
 	if (ip6 == NULL)
 		goto out;