[SK_BUFF]: Introduce skb_reset_transport_header(skb)

For the common, open coded 'skb->h.raw = skb->data' operation, so that we can
later turn skb->h.raw into a offset, reducing the size of struct sk_buff in
64bit land while possibly keeping it as a pointer on 32bit.

This one touches just the most simple cases:

skb->h.raw = skb->data;
skb->h.raw = {skb_push|[__]skb_pull}()

The next ones will handle the slightly more "complex" cases.

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

drivers/infiniband/hw/cxgb3/iwch_cm.c

@@ -507,7 +507,7 @@ static void send_mpa_req(struct iwch_ep *ep, struct sk_buff *skb)
 	 */
 	skb_get(skb);
 	set_arp_failure_handler(skb, arp_failure_discard);
-	skb->h.raw = skb->data;
+	skb_reset_transport_header(skb);
 	len = skb->len;
 	req = (struct tx_data_wr *) skb_push(skb, sizeof(*req));
 	req->wr_hi = htonl(V_WR_OP(FW_WROPCODE_OFLD_TX_DATA));
@@ -559,7 +559,7 @@ static int send_mpa_reject(struct iwch_ep *ep, const void *pdata, u8 plen)
 	skb_get(skb);
 	skb->priority = CPL_PRIORITY_DATA;
 	set_arp_failure_handler(skb, arp_failure_discard);
-	skb->h.raw = skb->data;
+	skb_reset_transport_header(skb);
 	req = (struct tx_data_wr *) skb_push(skb, sizeof(*req));
 	req->wr_hi = htonl(V_WR_OP(FW_WROPCODE_OFLD_TX_DATA));
 	req->wr_lo = htonl(V_WR_TID(ep->hwtid));
@@ -610,7 +610,7 @@ static int send_mpa_reply(struct iwch_ep *ep, const void *pdata, u8 plen)
 	 */
 	skb_get(skb);
 	set_arp_failure_handler(skb, arp_failure_discard);
-	skb->h.raw = skb->data;
+	skb_reset_transport_header(skb);
 	len = skb->len;
 	req = (struct tx_data_wr *) skb_push(skb, sizeof(*req));
 	req->wr_hi = htonl(V_WR_OP(FW_WROPCODE_OFLD_TX_DATA));

drivers/net/appletalk/cops.c

@@ -855,7 +855,7 @@ static void cops_rx(struct net_device *dev)
 
         skb_reset_mac_header(skb);    /* Point to entire packet. */
         skb_pull(skb,3);
-        skb->h.raw      = skb->data;    /* Point to data (Skip header). */
+        skb_reset_transport_header(skb);    /* Point to data (Skip header). */
 
         /* Update the counters. */
         lp->stats.rx_packets++;

drivers/net/appletalk/ltpc.c

@@ -776,7 +776,7 @@ static int sendup_buffer (struct net_device *dev)
 	/* copy ddp(s,e)hdr + contents */
 	memcpy(skb->data,(void*)ltdmabuf,len);
 
-	skb->h.raw = skb->data;
+	skb_reset_transport_header(skb);
 
 	stats->rx_packets++;
 	stats->rx_bytes+=skb->len;
@@ -923,7 +923,7 @@ static int ltpc_xmit(struct sk_buff *skb, struct net_device *dev)
 	cbuf.laptype = skb->data[2];
 	skb_pull(skb,3);	/* skip past LLAP header */
 	cbuf.length = skb->len;	/* this is host order */
-	skb->h.raw=skb->data;
+	skb_reset_transport_header(skb);
 
 	if(debug & DEBUG_UPPER) {
 		printk("command ");

drivers/net/cxgb3/sge.c

@@ -1622,7 +1622,7 @@ static inline int rx_offload(struct t3cdev *tdev, struct sge_rspq *rq,
 	rq->offload_pkts++;
 	skb_reset_mac_header(skb);
 	skb_reset_network_header(skb);
-	skb->h.raw = skb->data;
+	skb_reset_transport_header(skb);
 
 	if (rq->polling) {
 		rx_gather[gather_idx++] = skb;

include/linux/dccp.h

@@ -265,9 +265,9 @@ static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb)
 
 static inline struct dccp_hdr *dccp_zeroed_hdr(struct sk_buff *skb, int headlen)
 {
-	skb->h.raw = skb_push(skb, headlen);
-	memset(skb->h.raw, 0, headlen);
-	return dccp_hdr(skb);
+	skb_push(skb, headlen);
+	skb_reset_transport_header(skb);
+	return memset(skb->h.raw, 0, headlen);
 }
 
 static inline struct dccp_hdr_ext *dccp_hdrx(const struct sk_buff *skb)

include/linux/skbuff.h

@@ -957,6 +957,11 @@ static inline void skb_reserve(struct sk_buff *skb, int len)
 	skb->tail += len;
 }
 
+static inline void skb_reset_transport_header(struct sk_buff *skb)
+{
+	skb->h.raw = skb->data;
+}
+
 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
 {
 	return skb->nh.raw;

net/appletalk/aarp.c

@@ -119,7 +119,7 @@ static void __aarp_send_query(struct aarp_entry *a)
 	/* Set up the buffer */
 	skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length);
 	skb_reset_network_header(skb);
-	skb->h.raw	 = skb->data;
+	skb_reset_transport_header(skb);
 	skb_put(skb, sizeof(*eah));
 	skb->protocol    = htons(ETH_P_ATALK);
 	skb->dev	 = dev;
@@ -166,7 +166,7 @@ static void aarp_send_reply(struct net_device *dev, struct atalk_addr *us,
 	/* Set up the buffer */
 	skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length);
 	skb_reset_network_header(skb);
-	skb->h.raw	 = skb->data;
+	skb_reset_transport_header(skb);
 	skb_put(skb, sizeof(*eah));
 	skb->protocol    = htons(ETH_P_ATALK);
 	skb->dev	 = dev;
@@ -217,7 +217,7 @@ static void aarp_send_probe(struct net_device *dev, struct atalk_addr *us)
 	/* Set up the buffer */
 	skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length);
 	skb_reset_network_header(skb);
-	skb->h.raw	 = skb->data;
+	skb_reset_transport_header(skb);
 	skb_put(skb, sizeof(*eah));
 	skb->protocol    = htons(ETH_P_ATALK);
 	skb->dev	 = dev;

net/appletalk/ddp.c

@@ -1275,7 +1275,7 @@ static int handle_ip_over_ddp(struct sk_buff *skb)
 	skb->protocol = htons(ETH_P_IP);
 	skb_pull(skb, 13);
 	skb->dev   = dev;
-	skb->h.raw = skb->data;
+	skb_reset_transport_header(skb);
 
 	stats = dev->priv;
 	stats->rx_packets++;
@@ -1522,7 +1522,7 @@ static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
 		/* Non routable, so force a drop if we slip up later */
 		ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
 	}
-	skb->h.raw = skb->data;
+	skb_reset_transport_header(skb);
 
 	return atalk_rcv(skb, dev, pt, orig_dev);
 freeit:

net/ax25/af_ax25.c

@@ -1631,8 +1631,8 @@ static int ax25_recvmsg(struct kiocb *iocb, struct socket *sock,
 	if (!ax25_sk(sk)->pidincl)
 		skb_pull(skb, 1);		/* Remove PID */
 
-	skb->h.raw = skb->data;
-	copied     = skb->len;
+	skb_reset_transport_header(skb);
+	copied = skb->len;
 
 	if (copied > size) {
 		copied = size;

net/ax25/ax25_in.c

@@ -62,7 +62,7 @@ static int ax25_rx_fragment(ax25_cb *ax25, struct sk_buff *skb)
 
 					skbn->dev   = ax25->ax25_dev->dev;
 					skb_reset_network_header(skbn);
-					skbn->h.raw = skbn->data;
+					skb_reset_transport_header(skbn);
 
 					/* Copy data from the fragments */
 					while ((skbo = skb_dequeue(&ax25->frag_queue)) != NULL) {
@@ -196,7 +196,7 @@ static int ax25_rcv(struct sk_buff *skb, struct net_device *dev,
 	 *	Process the AX.25/LAPB frame.
 	 */
 
-	skb->h.raw = skb->data;
+	skb_reset_transport_header(skb);
 
 	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) {
 		kfree_skb(skb);
@@ -246,7 +246,7 @@ static int ax25_rcv(struct sk_buff *skb, struct net_device *dev,
 		switch (skb->data[1]) {
 		case AX25_P_IP:
 			skb_pull(skb,2);		/* drop PID/CTRL */
-			skb->h.raw    = skb->data;
+			skb_reset_transport_header(skb);
 			skb_reset_network_header(skb);
 			skb->dev      = dev;
 			skb->pkt_type = PACKET_HOST;
@@ -256,7 +256,7 @@ static int ax25_rcv(struct sk_buff *skb, struct net_device *dev,
 
 		case AX25_P_ARP:
 			skb_pull(skb,2);
-			skb->h.raw    = skb->data;
+			skb_reset_transport_header(skb);
 			skb_reset_network_header(skb);
 			skb->dev      = dev;
 			skb->pkt_type = PACKET_HOST;

net/bluetooth/af_bluetooth.c

@@ -221,7 +221,7 @@ int bt_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
 		copied = len;
 	}
 
-	skb->h.raw = skb->data;
+	skb_reset_transport_header(skb);
 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 
 	skb_free_datagram(sk, skb);

net/bluetooth/hci_core.c

@@ -1074,11 +1074,11 @@ static void hci_add_acl_hdr(struct sk_buff *skb, __u16 handle, __u16 flags)
 	struct hci_acl_hdr *hdr;
 	int len = skb->len;
 
-	hdr = (struct hci_acl_hdr *) skb_push(skb, HCI_ACL_HDR_SIZE);
+	skb_push(skb, HCI_ACL_HDR_SIZE);
+	skb_reset_transport_header(skb);
+	hdr = (struct hci_acl_hdr *)skb->h.raw;
 	hdr->handle = cpu_to_le16(hci_handle_pack(handle, flags));
 	hdr->dlen   = cpu_to_le16(len);
-
-	skb->h.raw = (void *) hdr;
 }
 
 int hci_send_acl(struct hci_conn *conn, struct sk_buff *skb, __u16 flags)
@@ -1143,7 +1143,8 @@ int hci_send_sco(struct hci_conn *conn, struct sk_buff *skb)
 	hdr.handle = cpu_to_le16(conn->handle);
 	hdr.dlen   = skb->len;
 
-	skb->h.raw = skb_push(skb, HCI_SCO_HDR_SIZE);
+	skb_push(skb, HCI_SCO_HDR_SIZE);
+	skb_reset_transport_header(skb);
 	memcpy(skb->h.raw, &hdr, HCI_SCO_HDR_SIZE);
 
 	skb->dev = (void *) hdev;

net/bluetooth/hci_sock.c

@@ -375,7 +375,7 @@ static int hci_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
 		copied = len;
 	}
 
-	skb->h.raw = skb->data;
+	skb_reset_transport_header(skb);
 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 
 	hci_sock_cmsg(sk, msg, skb);

net/core/dev.c

@@ -1773,7 +1773,7 @@ int netif_receive_skb(struct sk_buff *skb)
 	__get_cpu_var(netdev_rx_stat).total++;
 
 	skb_reset_network_header(skb);
-	skb->h.raw = skb->data;
+	skb_reset_transport_header(skb);
 	skb->mac_len = skb->nh.raw - skb->mac.raw;
 
 	pt_prev = NULL;

net/core/netpoll.c

@@ -362,7 +362,7 @@ static void arp_reply(struct sk_buff *skb)
 		return;
 
 	skb_reset_network_header(skb);
-	skb->h.raw = skb->data;
+	skb_reset_transport_header(skb);
 	arp = arp_hdr(skb);
 
 	if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&

net/decnet/dn_nsp_in.c

@@ -725,7 +725,7 @@ static int dn_nsp_rx_packet(struct sk_buff *skb)
 	if (!pskb_may_pull(skb, 2))
 		goto free_out;
 
-	skb->h.raw    = skb->data;
+	skb_reset_transport_header(skb);
 	cb->nsp_flags = *ptr++;
 
 	if (decnet_debug_level & 2)

net/decnet/dn_nsp_out.c

@@ -79,7 +79,7 @@ static void dn_nsp_send(struct sk_buff *skb)
 	struct dst_entry *dst;
 	struct flowi fl;
 
-	skb->h.raw = skb->data;
+	skb_reset_transport_header(skb);
 	scp->stamp = jiffies;
 
 	dst = sk_dst_check(sk, 0);

net/decnet/dn_route.c

@@ -504,7 +504,7 @@ static int dn_route_rx_long(struct sk_buff *skb)
 		goto drop_it;
 
 	skb_pull(skb, 20);
-	skb->h.raw = skb->data;
+	skb_reset_transport_header(skb);
 
 	/* Destination info */
 	ptr += 2;
@@ -542,7 +542,7 @@ static int dn_route_rx_short(struct sk_buff *skb)
 		goto drop_it;
 
 	skb_pull(skb, 5);
-	skb->h.raw = skb->data;
+	skb_reset_transport_header(skb);
 
 	cb->dst = *(__le16 *)ptr;
 	ptr += 2;

net/ipv4/af_inet.c

@@ -1120,7 +1120,8 @@ static int inet_gso_send_check(struct sk_buff *skb)
 	if (unlikely(!pskb_may_pull(skb, ihl)))
 		goto out;
 
-	skb->h.raw = __skb_pull(skb, ihl);
+	__skb_pull(skb, ihl);
+	skb_reset_transport_header(skb);
 	iph = ip_hdr(skb);
 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
 	err = -EPROTONOSUPPORT;
@@ -1163,7 +1164,8 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb, int features)
 	if (unlikely(!pskb_may_pull(skb, ihl)))
 		goto out;
 
-	skb->h.raw = __skb_pull(skb, ihl);
+	__skb_pull(skb, ihl);
+	skb_reset_transport_header(skb);
 	iph = ip_hdr(skb);
 	id = ntohs(iph->id);
 	proto = iph->protocol & (MAX_INET_PROTOS - 1);

net/ipv4/ah4.c

@@ -182,7 +182,8 @@ static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
 	}
 	((struct iphdr*)work_buf)->protocol = ah->nexthdr;
 	skb->nh.raw += ah_hlen;
-	skb->h.raw = memcpy(skb_network_header(skb), work_buf, ihl);
+	memcpy(skb_network_header(skb), work_buf, ihl);
+	skb->h.raw = skb->nh.raw;
 	__skb_pull(skb, ah_hlen + ihl);
 
 	return 0;