[TCP]: Introduce tcp_hdrlen() and tcp_optlen()

The ip_hdrlen() buddy, created to reduce the number of skb->h.th-> uses and to
avoid the longer, open coded equivalent.

Ditched a no-op in bnx2 in the process.

I wonder if we should have a BUG_ON(skb->h.th->doff < 5) in tcp_optlen()...

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

@@ -1307,7 +1307,7 @@ static int atl1_tso(struct atl1_adapter *adapter, struct sk_buff *skb,
 
 			tso->tsopl |= (iph->ihl &
 				CSUM_PARAM_IPHL_MASK) << CSUM_PARAM_IPHL_SHIFT;
-			tso->tsopl |= ((skb->h.th->doff << 2) &
+			tso->tsopl |= (tcp_hdrlen(skb) &
 				TSO_PARAM_TCPHDRLEN_MASK) << TSO_PARAM_TCPHDRLEN_SHIFT;
 			tso->tsopl |= (skb_shinfo(skb)->gso_size &
 				TSO_PARAM_MSS_MASK) << TSO_PARAM_MSS_SHIFT;
@@ -1369,8 +1369,7 @@ static void atl1_tx_map(struct atl1_adapter *adapter,
 
 	if (tcp_seg) {
 		/* TSO/GSO */
-		proto_hdr_len = (skb_transport_offset(skb) +
-				 (skb->h.th->doff << 2));
+		proto_hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
 		buffer_info->length = proto_hdr_len;
 		page = virt_to_page(skb->data);
 		offset = (unsigned long)skb->data & ~PAGE_MASK;
@@ -1563,7 +1562,7 @@ static int atl1_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
 	if (mss) {
 		if (skb->protocol == htons(ETH_P_IP)) {
 			proto_hdr_len = (skb_transport_offset(skb) +
-					 (skb->h.th->doff << 2));
+					 tcp_hdrlen(skb));
 			if (unlikely(proto_hdr_len > len)) {
 				dev_kfree_skb_any(skb);
 				return NETDEV_TX_OK;

drivers/net/bnx2.c

@@ -4521,13 +4521,12 @@ bnx2_start_xmit(struct sk_buff *skb, struct net_device *dev)
 			return NETDEV_TX_OK;
 		}
 
-		tcp_opt_len = ((skb->h.th->doff - 5) * 4);
 		vlan_tag_flags |= TX_BD_FLAGS_SW_LSO;
 
 		tcp_opt_len = 0;
-		if (skb->h.th->doff > 5) {
-			tcp_opt_len = (skb->h.th->doff - 5) << 2;
-		}
+		if (skb->h.th->doff > 5)
+			tcp_opt_len = tcp_optlen(skb);
+
 		ip_tcp_len = ip_hdrlen(skb) + sizeof(struct tcphdr);
 
 		iph = ip_hdr(skb);

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_transport_offset(skb) + (skb->h.th->doff << 2));
+		hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
 		mss = skb_shinfo(skb)->gso_size;
 		if (skb->protocol == htons(ETH_P_IP)) {
 			struct iphdr *iph = ip_hdr(skb);
@@ -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_transport_offset(skb) + (skb->h.th->doff << 2));
+		hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
 		if (skb->data_len && (hdr_len == (skb->len - skb->data_len))) {
 			switch (adapter->hw.mac_type) {
 				unsigned int pull_size;

drivers/net/ehea/ehea_main.c

@@ -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 + ip_hdrlen(skb) + (skb->h.th->doff * 4);
+	headersize = ETH_HLEN + ip_hdrlen(skb) + tcp_hdrlen(skb);
 
 	skb_data_size = skb->len - skb->data_len;
 

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_transport_offset(skb) + (skb->h.th->doff << 2));
+		hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
 		mss = skb_shinfo(skb)->gso_size;
 		iph = ip_hdr(skb);
 		iph->tot_len = 0;

drivers/net/myri10ge/myri10ge.c

@@ -2054,8 +2054,7 @@ again:
 		 * 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_transport_offset(skb) +
-			    (skb->h.th->doff << 2));
+		cum_len = -(skb_transport_offset(skb) + tcp_hdrlen(skb));
 
 		/* for TSO, pseudo_hdr_offset holds mss.
 		 * The firmware figures out where to put

drivers/net/netxen/netxen_nic_hw.c

@@ -374,8 +374,7 @@ void netxen_tso_check(struct netxen_adapter *adapter,
 {
 	if (desc->mss) {
 		desc->total_hdr_length = (sizeof(struct ethhdr) +
-					  ip_hdrlen(skb) +
-					  skb->h.th->doff * 4);
+					  ip_hdrlen(skb) + tcp_hdrlen(skb));
 		netxen_set_cmd_desc_opcode(desc, TX_TCP_LSO);
 	} else if (skb->ip_summed == CHECKSUM_PARTIAL) {
 		if (ip_hdr(skb)->protocol == IPPROTO_TCP) {

drivers/net/netxen/netxen_nic_main.c

@@ -779,7 +779,7 @@ 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 ((ip_hdrlen(skb) + skb->h.th->doff * 4 +
+			if ((ip_hdrlen(skb) + tcp_hdrlen(skb) +
 			     sizeof(struct ethhdr)) >
 			    (sizeof(struct cmd_desc_type0) - 2)) {
 				no_of_desc++;

drivers/net/sky2.c

@@ -1392,7 +1392,7 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
 	/* Check for TCP Segmentation Offload */
 	mss = skb_shinfo(skb)->gso_size;
 	if (mss != 0) {
-		mss += ((skb->h.th->doff - 5) * 4);	/* TCP options */
+		mss += tcp_optlen(skb); /* TCP options */
 		mss += ip_hdrlen(skb) + sizeof(struct tcphdr);
 		mss += ETH_HLEN;
 

drivers/net/tg3.c

@@ -3911,7 +3911,7 @@ static int tg3_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		else {
 			struct iphdr *iph = ip_hdr(skb);
 
-			tcp_opt_len = ((skb->h.th->doff - 5) * 4);
+			tcp_opt_len = tcp_optlen(skb);
 			ip_tcp_len = ip_hdrlen(skb) + sizeof(struct tcphdr);
 
 			iph->check = 0;
@@ -4065,7 +4065,7 @@ static int tg3_start_xmit_dma_bug(struct sk_buff *skb, struct net_device *dev)
 			goto out_unlock;
 		}
 
-		tcp_opt_len = ((skb->h.th->doff - 5) * 4);
+		tcp_opt_len = tcp_optlen(skb);
 		ip_tcp_len = ip_hdrlen(skb) + sizeof(struct tcphdr);
 
 		hdr_len = ip_tcp_len + tcp_opt_len;

drivers/s390/net/qeth_eddp.c

@@ -477,13 +477,13 @@ qeth_eddp_fill_context_tcp(struct qeth_eddp_context *ctx,
 						  skb_network_header(skb),
 						  ip_hdrlen(skb),
 						  skb->h.raw,
-						  skb->h.th->doff * 4);
+						  tcp_hdrlen(skb));
 	else
 		eddp = qeth_eddp_create_eddp_data(qhdr,
 						  skb_network_header(skb),
 						  sizeof(struct ipv6hdr),
 						  skb->h.raw,
-						  skb->h.th->doff * 4);
+						  tcp_hdrlen(skb));
 
 	if (eddp == NULL) {
 		QETH_DBF_TEXT(trace, 2, "eddpfcnm");
@@ -596,11 +596,11 @@ qeth_eddp_create_context_tcp(struct qeth_card *card, struct sk_buff *skb,
 		ctx = qeth_eddp_create_context_generic(card, skb,
 						       (sizeof(struct qeth_hdr) +
 						        ip_hdrlen(skb) +
-							skb->h.th->doff * 4));
+							tcp_hdrlen(skb)));
 	else if (skb->protocol == htons(ETH_P_IPV6))
 		ctx = qeth_eddp_create_context_generic(card, skb,
 			sizeof(struct qeth_hdr) + sizeof(struct ipv6hdr) +
-			skb->h.th->doff*4);
+			tcp_hdrlen(skb));
 	else
 		QETH_DBF_TEXT(trace, 2, "cetcpinv");
 

include/linux/tcp.h

@@ -178,6 +178,16 @@ struct tcp_md5sig {
 #include <net/inet_connection_sock.h>
 #include <net/inet_timewait_sock.h>
 
+static inline unsigned int tcp_hdrlen(const struct sk_buff *skb)
+{
+	return skb->h.th->doff * 4;
+}
+
+static inline unsigned int tcp_optlen(const struct sk_buff *skb)
+{
+	return (skb->h.th->doff - 5) * 4;
+}
+
 /* This defines a selective acknowledgement block. */
 struct tcp_sack_block_wire {
 	__be32	start_seq;

net/ipv4/tcp_ipv4.c

@@ -1564,7 +1564,7 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
 		return 0;
 	}
 
-	if (skb->len < (skb->h.th->doff << 2) || tcp_checksum_complete(skb))
+	if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
 		goto csum_err;
 
 	if (sk->sk_state == TCP_LISTEN) {

net/ipv6/tcp_ipv6.c

@@ -1609,7 +1609,7 @@ static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
 		return 0;
 	}
 
-	if (skb->len < (skb->h.th->doff<<2) || tcp_checksum_complete(skb))
+	if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
 		goto csum_err;
 
 	if (sk->sk_state == TCP_LISTEN) {