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/nfc/port100.c

@@ -1089,9 +1089,8 @@ static int port100_in_set_rf(struct nfc_digital_dev *ddev, u8 rf)
 	if (!skb)
 		return -ENOMEM;
 
-	memcpy(skb_put(skb, sizeof(struct port100_in_rf_setting)),
-	       &in_rf_settings[rf],
-	       sizeof(struct port100_in_rf_setting));
+	skb_put_data(skb, &in_rf_settings[rf],
+		     sizeof(struct port100_in_rf_setting));
 
 	resp = port100_send_cmd_sync(dev, PORT100_CMD_IN_SET_RF, skb);
 
@@ -1133,7 +1132,7 @@ static int port100_in_set_framing(struct nfc_digital_dev *ddev, int param)
 	if (!skb)
 		return -ENOMEM;
 
-	memcpy(skb_put(skb, size), protocols, size);
+	skb_put_data(skb, protocols, size);
 
 	resp = port100_send_cmd_sync(dev, PORT100_CMD_IN_SET_PROTOCOL, skb);
 
@@ -1247,9 +1246,8 @@ static int port100_tg_set_rf(struct nfc_digital_dev *ddev, u8 rf)
 	if (!skb)
 		return -ENOMEM;
 
-	memcpy(skb_put(skb, sizeof(struct port100_tg_rf_setting)),
-	       &tg_rf_settings[rf],
-	       sizeof(struct port100_tg_rf_setting));
+	skb_put_data(skb, &tg_rf_settings[rf],
+		     sizeof(struct port100_tg_rf_setting));
 
 	resp = port100_send_cmd_sync(dev, PORT100_CMD_TG_SET_RF, skb);
 
@@ -1291,7 +1289,7 @@ static int port100_tg_set_framing(struct nfc_digital_dev *ddev, int param)
 	if (!skb)
 		return -ENOMEM;
 
-	memcpy(skb_put(skb, size), protocols, size);
+	skb_put_data(skb, protocols, size);
 
 	resp = port100_send_cmd_sync(dev, PORT100_CMD_TG_SET_PROTOCOL, skb);