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>

2 files changed, 2 insertions, 3 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/dvm/rx.c b/drivers/net/wireless/intel/iwlwifi/dvm/rx.c
index adfd6307edca..eaad7389b67c 100644
--- a/drivers/net/wireless/intel/iwlwifi/dvm/rx.c
+++ b/drivers/net/wireless/intel/iwlwifi/dvm/rx.c
@@ -657,7 +657,7 @@ static void iwlagn_pass_packet_to_mac80211(struct iwl_priv *priv,
 	 */
 	hdrlen = (len <= skb_tailroom(skb)) ? len : sizeof(*hdr);
 
-	memcpy(skb_put(skb, hdrlen), hdr, hdrlen);
+	skb_put_data(skb, hdr, hdrlen);
 	fraglen = len - hdrlen;
 
 	if (fraglen) {
diff --git a/drivers/net/wireless/intel/iwlwifi/dvm/tx.c b/drivers/net/wireless/intel/iwlwifi/dvm/tx.c
index 4b97371c3b42..adaa2f0097cc 100644
--- a/drivers/net/wireless/intel/iwlwifi/dvm/tx.c
+++ b/drivers/net/wireless/intel/iwlwifi/dvm/tx.c
@@ -319,8 +319,7 @@ int iwlagn_tx_skb(struct iwl_priv *priv,
 		if (noa_data &&
 		    pskb_expand_head(skb, 0, noa_data->length,
 				     GFP_ATOMIC) == 0) {
-			memcpy(skb_put(skb, noa_data->length),
-			       noa_data->data, noa_data->length);
+			skb_put_data(skb, noa_data->data, noa_data->length);
 			hdr = (struct ieee80211_hdr *)skb->data;
 		}
 	}