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, 2 insertions, 4 deletions

diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c
index 03a35c9f456d..1e3dc374bfde 100644
--- a/net/batman-adv/bat_v_ogm.c
+++ b/net/batman-adv/bat_v_ogm.c
@@ -166,8 +166,7 @@ static void batadv_v_ogm_send(struct work_struct *work)
 		goto reschedule;
 
 	skb_reserve(skb, ETH_HLEN);
-	pkt_buff = skb_put(skb, ogm_buff_len);
-	memcpy(pkt_buff, ogm_buff, ogm_buff_len);
+	pkt_buff = skb_put_data(skb, ogm_buff, ogm_buff_len);
 
 	ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 	ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno));
@@ -382,8 +381,7 @@ static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
 		goto out;
 
 	skb_reserve(skb, ETH_HLEN);
-	skb_buff = skb_put(skb, packet_len);
-	memcpy(skb_buff, ogm_received, packet_len);
+	skb_buff = skb_put_data(skb, ogm_received, packet_len);
 
 	/* apply forward penalty */
 	ogm_forward = (struct batadv_ogm2_packet *)skb_buff;