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>

1 files changed, 4 insertions, 3 deletions

diff --git a/net/nfc/nci/hci.c b/net/nfc/nci/hci.c
index a0ab26d535dc..d4a53ce818c3 100644
--- a/net/nfc/nci/hci.c
+++ b/net/nfc/nci/hci.c
@@ -187,7 +187,7 @@ static int nci_hci_send_data(struct nci_dev *ndev, u8 pipe,
 		*skb_push(skb, 1) = cb;
 
 		if (len > 0)
-			memcpy(skb_put(skb, len), data + i, len);
+			skb_put_data(skb, data + i, len);
 
 		r = nci_send_data(ndev, conn_info->conn_id, skb);
 		if (r < 0)
@@ -476,8 +476,9 @@ void nci_hci_data_received_cb(void *context,
 
 		skb_queue_walk(&ndev->hci_dev->rx_hcp_frags, frag_skb) {
 			msg_len = frag_skb->len - NCI_HCI_HCP_PACKET_HEADER_LEN;
-			memcpy(skb_put(hcp_skb, msg_len), frag_skb->data +
-			       NCI_HCI_HCP_PACKET_HEADER_LEN, msg_len);
+			skb_put_data(hcp_skb,
+				     frag_skb->data + NCI_HCI_HCP_PACKET_HEADER_LEN,
+				     msg_len);
 		}
 
 		skb_queue_purge(&ndev->hci_dev->rx_hcp_frags);