[SK_BUFF]: Introduce skb_transport_offset()

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

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/atl1/atl1_main.c

@@ -1326,8 +1326,8 @@ static int atl1_tx_csum(struct atl1_adapter *adapter, struct sk_buff *skb,
 	u8 css, cso;
 
 	if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
-		cso = skb->h.raw - skb->data;
-		css = (skb->h.raw + skb->csum_offset) - skb->data;
+		cso = skb_transport_offset(skb);
+		css = cso + skb->csum;
 		if (unlikely(cso & 0x1)) {
 			printk(KERN_DEBUG "%s: payload offset != even number\n",
 				atl1_driver_name);
@@ -1369,8 +1369,8 @@ static void atl1_tx_map(struct atl1_adapter *adapter,
 
 	if (tcp_seg) {
 		/* TSO/GSO */
-		proto_hdr_len =
-		    ((skb->h.raw - skb->data) + (skb->h.th->doff << 2));
+		proto_hdr_len = (skb_transport_offset(skb) +
+				 (skb->h.th->doff << 2));
 		buffer_info->length = proto_hdr_len;
 		page = virt_to_page(skb->data);
 		offset = (unsigned long)skb->data & ~PAGE_MASK;
@@ -1562,7 +1562,7 @@ static int atl1_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
 	mss = skb_shinfo(skb)->gso_size;
 	if (mss) {
 		if (skb->protocol == htons(ETH_P_IP)) {
-			proto_hdr_len = ((skb->h.raw - skb->data) +
+			proto_hdr_len = (skb_transport_offset(skb) +
 					 (skb->h.th->doff << 2));
 			if (unlikely(proto_hdr_len > len)) {
 				dev_kfree_skb_any(skb);

drivers/net/cassini.c

@@ -2821,10 +2821,8 @@ static inline int cas_xmit_tx_ringN(struct cas *cp, int ring,
 
 	ctrl = 0;
 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
-		u64 csum_start_off, csum_stuff_off;
-
-		csum_start_off = (u64) (skb->h.raw - skb->data);
-		csum_stuff_off = csum_start_off + skb->csum_offset;
+		const u64 csum_start_off = skb_transport_offset(skb);
+		const u64 csum_stuff_off = csum_start_off + skb->csum_offset;
 
 		ctrl =  TX_DESC_CSUM_EN |
 			CAS_BASE(TX_DESC_CSUM_START, csum_start_off) |

drivers/net/cxgb3/sge.c

@@ -1319,9 +1319,10 @@ static void write_ofld_wr(struct adapter *adap, struct sk_buff *skb,
 	/* Only TX_DATA builds SGLs */
 
 	from = (struct work_request_hdr *)skb->data;
-	memcpy(&d->flit[1], &from[1], skb->h.raw - skb->data - sizeof(*from));
+	memcpy(&d->flit[1], &from[1],
+	       skb_transport_offset(skb) - sizeof(*from));
 
-	flits = (skb->h.raw - skb->data) / 8;
+	flits = skb_transport_offset(skb) / 8;
 	sgp = ndesc == 1 ? (struct sg_ent *)&d->flit[flits] : sgl;
 	sgl_flits = make_sgl(skb, sgp, skb->h.raw, skb->tail - skb->h.raw,
 			     adap->pdev);
@@ -1349,7 +1350,7 @@ static inline unsigned int calc_tx_descs_ofld(const struct sk_buff *skb)
 	if (skb->len <= WR_LEN && cnt == 0)
 		return 1;	/* packet fits as immediate data */
 
-	flits = (skb->h.raw - skb->data) / 8;	/* headers */
+	flits = skb_transport_offset(skb) / 8;	/* headers */
 	if (skb->tail != skb->h.raw)
 		cnt++;
 	return flits_to_desc(flits + sgl_len(cnt));

drivers/net/e1000/e1000_main.c

@@ -2887,7 +2887,7 @@ e1000_tso(struct e1000_adapter *adapter, struct e1000_tx_ring *tx_ring,
 				return err;
 		}
 
-		hdr_len = ((skb->h.raw - skb->data) + (skb->h.th->doff << 2));
+		hdr_len = (skb_transport_offset(skb) + (skb->h.th->doff << 2));
 		mss = skb_shinfo(skb)->gso_size;
 		if (skb->protocol == htons(ETH_P_IP)) {
 			struct iphdr *iph = ip_hdr(skb);
@@ -2897,7 +2897,7 @@ e1000_tso(struct e1000_adapter *adapter, struct e1000_tx_ring *tx_ring,
 							      iph->daddr, 0,
 							      IPPROTO_TCP, 0);
 			cmd_length = E1000_TXD_CMD_IP;
-			ipcse = skb->h.raw - skb->data - 1;
+			ipcse = skb_transport_offset(skb) - 1;
 		} else if (skb->protocol == htons(ETH_P_IPV6)) {
 			ipv6_hdr(skb)->payload_len = 0;
 			skb->h.th->check =
@@ -2908,7 +2908,7 @@ e1000_tso(struct e1000_adapter *adapter, struct e1000_tx_ring *tx_ring,
 		}
 		ipcss = skb_network_offset(skb);
 		ipcso = (void *)&(ip_hdr(skb)->check) - (void *)skb->data;
-		tucss = skb->h.raw - skb->data;
+		tucss = skb_transport_offset(skb);
 		tucso = (void *)&(skb->h.th->check) - (void *)skb->data;
 		tucse = 0;
 
@@ -2950,7 +2950,7 @@ e1000_tx_csum(struct e1000_adapter *adapter, struct e1000_tx_ring *tx_ring,
 	uint8_t css;
 
 	if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
-		css = skb->h.raw - skb->data;
+		css = skb_transport_offset(skb);
 
 		i = tx_ring->next_to_use;
 		buffer_info = &tx_ring->buffer_info[i];
@@ -3292,7 +3292,7 @@ e1000_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
 		/* TSO Workaround for 82571/2/3 Controllers -- if skb->data
 		* points to just header, pull a few bytes of payload from
 		* frags into skb->data */
-		hdr_len = ((skb->h.raw - skb->data) + (skb->h.th->doff << 2));
+		hdr_len = (skb_transport_offset(skb) + (skb->h.th->doff << 2));
 		if (skb->data_len && (hdr_len == (skb->len - skb->data_len))) {
 			switch (adapter->hw.mac_type) {
 				unsigned int pull_size;

drivers/net/ixgb/ixgb_main.c

@@ -1190,7 +1190,7 @@ ixgb_tso(struct ixgb_adapter *adapter, struct sk_buff *skb)
 				return err;
 		}
 
-		hdr_len = ((skb->h.raw - skb->data) + (skb->h.th->doff << 2));
+		hdr_len = (skb_transport_offset(skb) + (skb->h.th->doff << 2));
 		mss = skb_shinfo(skb)->gso_size;
 		iph = ip_hdr(skb);
 		iph->tot_len = 0;
@@ -1199,8 +1199,8 @@ ixgb_tso(struct ixgb_adapter *adapter, struct sk_buff *skb)
 						      0, IPPROTO_TCP, 0);
 		ipcss = skb_network_offset(skb);
 		ipcso = (void *)&(iph->check) - (void *)skb->data;
-		ipcse = skb->h.raw - skb->data - 1;
-		tucss = skb->h.raw - skb->data;
+		ipcse = skb_transport_offset(skb) - 1;
+		tucss = skb_transport_offset(skb);
 		tucso = (void *)&(skb->h.th->check) - (void *)skb->data;
 		tucse = 0;
 
@@ -1245,7 +1245,7 @@ ixgb_tx_csum(struct ixgb_adapter *adapter, struct sk_buff *skb)
 
 	if(likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
 		struct ixgb_buffer *buffer_info;
-		css = skb->h.raw - skb->data;
+		css = skb_transport_offset(skb);
 		cso = css + skb->csum_offset;
 
 		i = adapter->tx_ring.next_to_use;

drivers/net/myri10ge/myri10ge.c

@@ -2029,7 +2029,7 @@ static int myri10ge_xmit(struct sk_buff *skb, struct net_device *dev)
 	odd_flag = 0;
 	flags = (MXGEFW_FLAGS_NO_TSO | MXGEFW_FLAGS_FIRST);
 	if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
-		cksum_offset = (skb->h.raw - skb->data);
+		cksum_offset = skb_transport_offset(skb);
 		pseudo_hdr_offset = cksum_offset + skb->csum_offset;
 		/* If the headers are excessively large, then we must
 		 * fall back to a software checksum */
@@ -2054,7 +2054,8 @@ static int myri10ge_xmit(struct sk_buff *skb, struct net_device *dev)
 		 * send loop that we are still in the
 		 * header portion of the TSO packet.
 		 * TSO header must be at most 134 bytes long */
-		cum_len = -((skb->h.raw - skb->data) + (skb->h.th->doff << 2));
+		cum_len = -(skb_transport_offset(skb) +
+			    (skb->h.th->doff << 2));
 
 		/* for TSO, pseudo_hdr_offset holds mss.
 		 * The firmware figures out where to put

drivers/net/netxen/netxen_nic_hw.c

@@ -387,7 +387,7 @@ void netxen_tso_check(struct netxen_adapter *adapter,
 		}
 	}
 	adapter->stats.xmitcsummed++;
-	desc->tcp_hdr_offset = skb->h.raw - skb->data;
+	desc->tcp_hdr_offset = skb_transport_offset(skb);
 	desc->ip_hdr_offset = skb_network_offset(skb);
 }
 

drivers/net/sk98lin/skge.c

@@ -1562,7 +1562,7 @@ struct sk_buff	*pMessage)	/* pointer to send-message              */
 	pTxd->pMBuf     = pMessage;
 
 	if (pMessage->ip_summed == CHECKSUM_PARTIAL) {
-		u16 hdrlen = pMessage->h.raw - pMessage->data;
+		u16 hdrlen = skb_transport_offset(pMessage);
 		u16 offset = hdrlen + pMessage->csum_offset;
 
 		if ((pMessage->h.ipiph->protocol == IPPROTO_UDP ) &&
@@ -1681,7 +1681,7 @@ struct sk_buff	*pMessage)	/* pointer to send-message              */
 	** Does the HW need to evaluate checksum for TCP or UDP packets? 
 	*/
 	if (pMessage->ip_summed == CHECKSUM_PARTIAL) {
-		u16 hdrlen = pMessage->h.raw - pMessage->data;
+		u16 hdrlen = skb_transport_offset(pMessage);
 		u16 offset = hdrlen + pMessage->csum_offset;
 
 		Control = BMU_STFWD;

drivers/net/skge.c

@@ -2654,7 +2654,7 @@ static int skge_xmit_frame(struct sk_buff *skb, struct net_device *dev)
 	td->dma_hi = map >> 32;
 
 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
-		int offset = skb->h.raw - skb->data;
+		const int offset = skb_transport_offset(skb);
 
 		/* This seems backwards, but it is what the sk98lin
 		 * does.  Looks like hardware is wrong?

drivers/net/sky2.c

@@ -1421,7 +1421,7 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
 
 	/* Handle TCP checksum offload */
 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
-		unsigned offset = skb->h.raw - skb->data;
+		const unsigned offset = skb_transport_offset(skb);
 		u32 tcpsum;
 
 		tcpsum = offset << 16;		/* sum start */

drivers/net/sungem.c

@@ -1028,10 +1028,8 @@ static int gem_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	ctrl = 0;
 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
-		u64 csum_start_off, csum_stuff_off;
-
-		csum_start_off = (u64) (skb->h.raw - skb->data);
-		csum_stuff_off = csum_start_off + skb->csum_offset;
+		const u64 csum_start_off = skb_transport_offset(skb);
+		const u64 csum_stuff_off = csum_start_off + skb->csum_offset;
 
 		ctrl = (TXDCTRL_CENAB |
 			(csum_start_off << 15) |

drivers/net/sunhme.c

@@ -2269,10 +2269,8 @@ static int happy_meal_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	tx_flags = TXFLAG_OWN;
 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
-		u32 csum_start_off, csum_stuff_off;
-
-		csum_start_off = (u32) (skb->h.raw - skb->data);
-		csum_stuff_off = csum_start_off + skb->csum_offset;
+		const u32 csum_start_off = skb_transport_offset(skb);
+		const u32 csum_stuff_off = csum_start_off + skb->csum_offset;
 
 		tx_flags = (TXFLAG_OWN | TXFLAG_CSENABLE |
 			    ((csum_start_off << 14) & TXFLAG_CSBUFBEGIN) |

include/linux/skbuff.h

@@ -962,6 +962,11 @@ static inline void skb_reset_transport_header(struct sk_buff *skb)
 	skb->h.raw = skb->data;
 }
 
+static inline int skb_transport_offset(const struct sk_buff *skb)
+{
+	return skb->h.raw - skb->data;
+}
+
 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
 {
 	return skb->nh.raw;

include/net/udplite.h

@@ -101,14 +101,14 @@ static inline int udplite_sender_cscov(struct udp_sock *up, struct udphdr *uh)
 
 static inline __wsum udplite_csum_outgoing(struct sock *sk, struct sk_buff *skb)
 {
-	int off, len, cscov = udplite_sender_cscov(udp_sk(sk), skb->h.uh);
+	int cscov = udplite_sender_cscov(udp_sk(sk), skb->h.uh);
 	__wsum csum = 0;
 
 	skb->ip_summed = CHECKSUM_NONE;     /* no HW support for checksumming */
 
 	skb_queue_walk(&sk->sk_write_queue, skb) {
-		off = skb->h.raw - skb->data;
-		len = skb->len - off;
+		const int off = skb_transport_offset(skb);
+		const int len = skb->len - off;
 
 		csum = skb_checksum(skb, off, (cscov > len)? len : cscov, csum);
 

net/core/dev.c

@@ -1156,7 +1156,7 @@ EXPORT_SYMBOL(netif_device_attach);
 int skb_checksum_help(struct sk_buff *skb)
 {
 	__wsum csum;
-	int ret = 0, offset = skb->h.raw - skb->data;
+	int ret = 0, offset = skb_transport_offset(skb);
 
 	if (skb->ip_summed == CHECKSUM_COMPLETE)
 		goto out_set_summed;

net/core/skbuff.c

@@ -1348,7 +1348,7 @@ void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to)
 	long csstart;
 
 	if (skb->ip_summed == CHECKSUM_PARTIAL)
-		csstart = skb->h.raw - skb->data;
+		csstart = skb_transport_offset(skb);
 	else
 		csstart = skb_headlen(skb);
 

net/ipv4/esp4.c

@@ -27,7 +27,7 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
 	int nfrags;
 
 	/* Strip IP+ESP header. */
-	__skb_pull(skb, skb->h.raw - skb->data);
+	__skb_pull(skb, skb_transport_offset(skb));
 	/* Now skb is pure payload to encrypt */
 
 	err = -ENOMEM;

net/ipv4/udp.c

@@ -435,7 +435,7 @@ static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
 		 * fragments on the socket so that all csums of sk_buffs
 		 * should be together
 		 */
-		offset = skb->h.raw - skb->data;
+		offset = skb_transport_offset(skb);
 		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
 
 		skb->ip_summed = CHECKSUM_NONE;

net/ipv6/esp6.c

@@ -42,21 +42,18 @@
 static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
 {
 	int err;
-	int hdr_len;
 	struct ipv6hdr *top_iph;
 	struct ipv6_esp_hdr *esph;
 	struct crypto_blkcipher *tfm;
 	struct blkcipher_desc desc;
-	struct esp_data *esp;
 	struct sk_buff *trailer;
 	int blksize;
 	int clen;
 	int alen;
 	int nfrags;
-
-	esp = x->data;
-	hdr_len = skb->h.raw - skb->data +
-		  sizeof(*esph) + esp->conf.ivlen;
+	struct esp_data *esp = x->data;
+	int hdr_len = (skb_transport_offset(skb) +
+		       sizeof(*esph) + esp->conf.ivlen);
 
 	/* Strip IP+ESP header. */
 	__skb_pull(skb, hdr_len);

net/ipv6/exthdrs.c

@@ -146,7 +146,7 @@ static int ip6_parse_tlv(struct tlvtype_proc *procs, struct sk_buff **skbp)
 	int off = skb->h.raw - skb->nh.raw;
 	int len = ((skb->h.raw[1]+1)<<3);
 
-	if ((skb->h.raw + len) - skb->data > skb_headlen(skb))
+	if (skb_transport_offset(skb) + len > skb_headlen(skb))
 		goto bad;
 
 	off += 2;
@@ -288,8 +288,9 @@ static int ipv6_destopt_rcv(struct sk_buff **skbp)
 #endif
 	struct dst_entry *dst;
 
-	if (!pskb_may_pull(skb, (skb->h.raw-skb->data)+8) ||
-	    !pskb_may_pull(skb, (skb->h.raw-skb->data)+((skb->h.raw[1]+1)<<3))) {
+	if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
+	    !pskb_may_pull(skb, (skb_transport_offset(skb) +
+				 ((skb->h.raw[1] + 1) << 3)))) {
 		IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
 				 IPSTATS_MIB_INHDRERRORS);
 		kfree_skb(skb);
@@ -387,8 +388,9 @@ static int ipv6_rthdr_rcv(struct sk_buff **skbp)
 
 	in6_dev_put(idev);
 
-	if (!pskb_may_pull(skb, (skb->h.raw-skb->data)+8) ||
-	    !pskb_may_pull(skb, (skb->h.raw-skb->data)+((skb->h.raw[1]+1)<<3))) {
+	if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
+	    !pskb_may_pull(skb, (skb_transport_offset(skb) +
+				 ((skb->h.raw[1] + 1) << 3)))) {
 		IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
 				 IPSTATS_MIB_INHDRERRORS);
 		kfree_skb(skb);

net/ipv6/ip6_input.c

@@ -160,7 +160,7 @@ static inline int ip6_input_finish(struct sk_buff *skb)
 	rcu_read_lock();
 resubmit:
 	idev = ip6_dst_idev(skb->dst);
-	if (!pskb_pull(skb, skb->h.raw - skb->data))
+	if (!pskb_pull(skb, skb_transport_offset(skb)))
 		goto discard;
 	nhoff = IP6CB(skb)->nhoff;
 	nexthdr = skb_network_header(skb)[nhoff];

net/ipv6/ipcomp6.c

@@ -124,15 +124,13 @@ static int ipcomp6_output(struct xfrm_state *x, struct sk_buff *skb)
 {
 	int err;
 	struct ipv6hdr *top_iph;
-	int hdr_len;
 	struct ipv6_comp_hdr *ipch;
 	struct ipcomp_data *ipcd = x->data;
 	int plen, dlen;
 	u8 *start, *scratch;
 	struct crypto_comp *tfm;
 	int cpu;
-
-	hdr_len = skb->h.raw - skb->data;
+	int hdr_len = skb_transport_offset(skb);
 
 	/* check whether datagram len is larger than threshold */
 	if ((skb->len - hdr_len) < ipcd->threshold) {

net/ipv6/mip6.c

@@ -90,8 +90,9 @@ int mip6_mh_filter(struct sock *sk, struct sk_buff *skb)
 {
 	struct ip6_mh *mh;
 
-	if (!pskb_may_pull(skb, (skb->h.raw - skb->data) + 8) ||
-	    !pskb_may_pull(skb, (skb->h.raw - skb->data) + ((skb->h.raw[1] + 1) << 3)))
+	if (!pskb_may_pull(skb, (skb_transport_offset(skb)) + 8) ||
+	    !pskb_may_pull(skb, (skb_transport_offset(skb) +
+				 ((skb->h.raw[1] + 1) << 3))))
 		return -1;
 
 	mh = (struct ip6_mh *)skb->h.raw;