networking: introduce and use skb_put_data()

A common pattern with skb_put() is to just want to memcpy()
some data into the new space, introduce skb_put_data() for
this.

An spatch similar to the one for skb_put_zero() converts many
of the places using it:

    @@
    identifier p, p2;
    expression len, skb, data;
    type t, t2;
    @@
    (
    -p = skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    |
    -p = (t)skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, len);
    |
    -memcpy(p, data, len);
    )

    @@
    type t, t2;
    identifier p, p2;
    expression skb, data;
    @@
    t *p;
    ...
    (
    -p = skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    |
    -p = (t *)skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, sizeof(*p));
    |
    -memcpy(p, data, sizeof(*p));
    )

    @@
    expression skb, len, data;
    @@
    -memcpy(skb_put(skb, len), data, len);
    +skb_put_data(skb, data, len);

(again, manually post-processed to retain some comments)

Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/wireless/intersil/hostap/hostap_80211_tx.c

@@ -242,7 +242,7 @@ netdev_tx_t hostap_data_start_xmit(struct sk_buff *skb,
 		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
 	memcpy(skb_push(skb, hdr_len), &hdr, hdr_len);
 	if (use_wds == WDS_OWN_FRAME) {
-		memcpy(skb_put(skb, ETH_ALEN), &hdr.addr4, ETH_ALEN);
+		skb_put_data(skb, &hdr.addr4, ETH_ALEN);
 	}
 
 	iface->stats.tx_packets++;

drivers/net/wireless/intersil/hostap/hostap_ap.c

@@ -1000,7 +1000,7 @@ static void prism2_send_mgmt(struct net_device *dev,
 	hdrlen = hostap_80211_get_hdrlen(cpu_to_le16(type_subtype));
 	hdr = skb_put_zero(skb, hdrlen);
 	if (body)
-		memcpy(skb_put(skb, body_len), body, body_len);
+		skb_put_data(skb, body, body_len);
 
 	/* FIX: ctrl::ack sending used special HFA384X_TX_CTRL_802_11
 	 * tx_control instead of using local->tx_control */

drivers/net/wireless/intersil/hostap/hostap_hw.c

@@ -2005,7 +2005,7 @@ static void prism2_rx(local_info_t *local)
 		goto rx_dropped;
 	}
 	skb->dev = dev;
-	memcpy(skb_put(skb, hdr_len), &rxdesc, hdr_len);
+	skb_put_data(skb, &rxdesc, hdr_len);
 
 	if (len > 0)
 		res = hfa384x_from_bap(dev, BAP0, skb_put(skb, len), len);
@@ -2209,9 +2209,9 @@ static void hostap_tx_callback(local_info_t *local,
 		return;
 	}
 
-	memcpy(skb_put(skb, hdrlen), (void *) &txdesc->frame_control, hdrlen);
+	skb_put_data(skb, (void *)&txdesc->frame_control, hdrlen);
 	if (payload)
-		memcpy(skb_put(skb, len), payload, len);
+		skb_put_data(skb, payload, len);
 
 	skb->dev = local->dev;
 	skb_reset_mac_header(skb);
@@ -2362,8 +2362,7 @@ static void prism2_txexc(local_info_t *local)
 		struct sk_buff *skb;
 		skb = dev_alloc_skb(sizeof(txdesc));
 		if (skb) {
-			memcpy(skb_put(skb, sizeof(txdesc)), &txdesc,
-			       sizeof(txdesc));
+			skb_put_data(skb, &txdesc, sizeof(txdesc));
 			skb_queue_tail(&local->sta_tx_exc_list, skb);
 			tasklet_schedule(&local->sta_tx_exc_tasklet);
 		}
@@ -2460,7 +2459,7 @@ static void prism2_info(local_info_t *local)
 		goto out;
 	}
 
-	memcpy(skb_put(skb, sizeof(info)), &info, sizeof(info));
+	skb_put_data(skb, &info, sizeof(info));
 	if (left > 0 && hfa384x_from_bap(dev, BAP0, skb_put(skb, left), left))
 	{
 		spin_unlock(&local->baplock);

drivers/net/wireless/intersil/hostap/hostap_main.c

@@ -1045,7 +1045,7 @@ int prism2_sta_send_mgmt(local_info_t *local, u8 *dst, u16 stype,
 	memcpy(mgmt->sa, dev->dev_addr, ETH_ALEN);
 	memcpy(mgmt->bssid, dst, ETH_ALEN);
 	if (body)
-		memcpy(skb_put(skb, bodylen), body, bodylen);
+		skb_put_data(skb, body, bodylen);
 
 	meta = (struct hostap_skb_tx_data *) skb->cb;
 	memset(meta, 0, sizeof(*meta));