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>
diff --git a/drivers/bluetooth/hci_bcsp.c b/drivers/bluetooth/hci_bcsp.c
index 910ec96..d880f4e 100644
--- a/drivers/bluetooth/hci_bcsp.c
+++ b/drivers/bluetooth/hci_bcsp.c
@@ -125,7 +125,7 @@ static void bcsp_slip_msgdelim(struct sk_buff *skb)
 {
 	const char pkt_delim = 0xc0;
 
-	memcpy(skb_put(skb, 1), &pkt_delim, 1);
+	skb_put_data(skb, &pkt_delim, 1);
 }
 
 static void bcsp_slip_one_byte(struct sk_buff *skb, u8 c)
@@ -135,13 +135,13 @@ static void bcsp_slip_one_byte(struct sk_buff *skb, u8 c)
 
 	switch (c) {
 	case 0xc0:
-		memcpy(skb_put(skb, 2), &esc_c0, 2);
+		skb_put_data(skb, &esc_c0, 2);
 		break;
 	case 0xdb:
-		memcpy(skb_put(skb, 2), &esc_db, 2);
+		skb_put_data(skb, &esc_db, 2);
 		break;
 	default:
-		memcpy(skb_put(skb, 1), &c, 1);
+		skb_put_data(skb, &c, 1);
 	}
 }
 
@@ -423,7 +423,7 @@ static void bcsp_handle_le_pkt(struct hci_uart *hu)
 		BT_DBG("Found a LE conf pkt");
 		if (!nskb)
 			return;
-		memcpy(skb_put(nskb, 4), conf_rsp_pkt, 4);
+		skb_put_data(nskb, conf_rsp_pkt, 4);
 		hci_skb_pkt_type(nskb) = BCSP_LE_PKT;
 
 		skb_queue_head(&bcsp->unrel, nskb);
@@ -447,7 +447,7 @@ static inline void bcsp_unslip_one_byte(struct bcsp_struct *bcsp, unsigned char
 			bcsp->rx_esc_state = BCSP_ESCSTATE_ESC;
 			break;
 		default:
-			memcpy(skb_put(bcsp->rx_skb, 1), &byte, 1);
+			skb_put_data(bcsp->rx_skb, &byte, 1);
 			if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
 			    bcsp->rx_state != BCSP_W4_CRC)
 				bcsp_crc_update(&bcsp->message_crc, byte);
@@ -458,7 +458,7 @@ static inline void bcsp_unslip_one_byte(struct bcsp_struct *bcsp, unsigned char
 	case BCSP_ESCSTATE_ESC:
 		switch (byte) {
 		case 0xdc:
-			memcpy(skb_put(bcsp->rx_skb, 1), &c0, 1);
+			skb_put_data(bcsp->rx_skb, &c0, 1);
 			if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
 			    bcsp->rx_state != BCSP_W4_CRC)
 				bcsp_crc_update(&bcsp->message_crc, 0xc0);
@@ -467,7 +467,7 @@ static inline void bcsp_unslip_one_byte(struct bcsp_struct *bcsp, unsigned char
 			break;
 
 		case 0xdd:
-			memcpy(skb_put(bcsp->rx_skb, 1), &db, 1);
+			skb_put_data(bcsp->rx_skb, &db, 1);
 			if ((bcsp->rx_skb->data[0] & 0x40) != 0 &&
 			    bcsp->rx_state != BCSP_W4_CRC)
 				bcsp_crc_update(&bcsp->message_crc, 0xdb);