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, 6 deletions

diff --git a/drivers/net/wireless/marvell/mwifiex/cfg80211.c b/drivers/net/wireless/marvell/mwifiex/cfg80211.c
index 025bc06a19d6..c20e4944ef87 100644
--- a/drivers/net/wireless/marvell/mwifiex/cfg80211.c
+++ b/drivers/net/wireless/marvell/mwifiex/cfg80211.c
@@ -176,12 +176,10 @@ mwifiex_form_mgmt_frame(struct sk_buff *skb, const u8 *buf, size_t len)
 	memcpy(skb_push(skb, sizeof(pkt_type)), &pkt_type, sizeof(pkt_type));
 
 	/* Add packet data and address4 */
-	memcpy(skb_put(skb, sizeof(struct ieee80211_hdr_3addr)), buf,
-	       sizeof(struct ieee80211_hdr_3addr));
-	memcpy(skb_put(skb, ETH_ALEN), addr, ETH_ALEN);
-	memcpy(skb_put(skb, len - sizeof(struct ieee80211_hdr_3addr)),
-	       buf + sizeof(struct ieee80211_hdr_3addr),
-	       len - sizeof(struct ieee80211_hdr_3addr));
+	skb_put_data(skb, buf, sizeof(struct ieee80211_hdr_3addr));
+	skb_put_data(skb, addr, ETH_ALEN);
+	skb_put_data(skb, buf + sizeof(struct ieee80211_hdr_3addr),
+		     len - sizeof(struct ieee80211_hdr_3addr));
 
 	skb->priority = LOW_PRIO_TID;
 	__net_timestamp(skb);