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, 3 insertions, 5 deletions

diff --git a/net/irda/ircomm/ircomm_tty.c b/net/irda/ircomm/ircomm_tty.c
index f6061c4bb0a8..ec157c3419b5 100644
--- a/net/irda/ircomm/ircomm_tty.c
+++ b/net/irda/ircomm/ircomm_tty.c
@@ -690,7 +690,7 @@ static int ircomm_tty_write(struct tty_struct *tty,
 		}
 
 		/* Copy data */
-		memcpy(skb_put(skb,size), buf + len, size);
+		skb_put_data(skb, buf + len, size);
 
 		count -= size;
 		len += size;
diff --git a/net/irda/irlap_frame.c b/net/irda/irlap_frame.c
index b936b1251a66..bf56ac7dba96 100644
--- a/net/irda/irlap_frame.c
+++ b/net/irda/irlap_frame.c
@@ -392,8 +392,7 @@ void irlap_send_discovery_xid_frame(struct irlap_cb *self, int S, __u8 s,
 		info[0] = discovery->data.charset;
 
 		len = IRDA_MIN(discovery->name_len, skb_tailroom(tx_skb));
-		info = skb_put(tx_skb, len);
-		memcpy(info, discovery->data.info, len);
+		info = skb_put_data(tx_skb, discovery->data.info, len);
 	}
 	irlap_queue_xmit(self, tx_skb);
 }
@@ -1216,8 +1215,7 @@ void irlap_send_test_frame(struct irlap_cb *self, __u8 caddr, __u32 daddr,
 	frame->control = TEST_RSP | PF_BIT;
 
 	/* Copy info */
-	info = skb_put(tx_skb, cmd->len);
-	memcpy(info, cmd->data, cmd->len);
+	info = skb_put_data(tx_skb, cmd->data, cmd->len);
 
 	/* Return to sender */
 	irlap_wait_min_turn_around(self, &self->qos_tx);