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>

3 files changed, 4 insertions, 4 deletions

diff --git a/drivers/net/wan/farsync.c b/drivers/net/wan/farsync.c
index 33265eb50420..bd46b2552980 100644
--- a/drivers/net/wan/farsync.c
+++ b/drivers/net/wan/farsync.c
@@ -857,7 +857,7 @@ fst_rx_dma_complete(struct fst_card_info *card, struct fst_port_info *port,
 
 	dbg(DBG_TX, "fst_rx_dma_complete\n");
 	pi = port->index;
-	memcpy(skb_put(skb, len), card->rx_dma_handle_host, len);
+	skb_put_data(skb, card->rx_dma_handle_host, len);
 
 	/* Reset buffer descriptor */
 	FST_WRB(card, rxDescrRing[pi][rxp].bits, DMA_OWN);
diff --git a/drivers/net/wan/hdlc_ppp.c b/drivers/net/wan/hdlc_ppp.c
index 47fdb87d3567..f5b4ad45831a 100644
--- a/drivers/net/wan/hdlc_ppp.c
+++ b/drivers/net/wan/hdlc_ppp.c
@@ -234,9 +234,9 @@ static void ppp_tx_cp(struct net_device *dev, u16 pid, u8 code,
 	cp->len = htons(sizeof(struct cp_header) + magic_len + len);
 
 	if (magic_len)
-		memcpy(skb_put(skb, magic_len), &magic, magic_len);
+		skb_put_data(skb, &magic, magic_len);
 	if (len)
-		memcpy(skb_put(skb, len), data, len);
+		skb_put_data(skb, data, len);
 
 #if DEBUG_CP
 	BUG_ON(code >= CP_CODES);
diff --git a/drivers/net/wan/x25_asy.c b/drivers/net/wan/x25_asy.c
index 878b05d06fc7..40ee80c03c94 100644
--- a/drivers/net/wan/x25_asy.c
+++ b/drivers/net/wan/x25_asy.c
@@ -202,7 +202,7 @@ static void x25_asy_bump(struct x25_asy *sl)
 		return;
 	}
 	skb_push(skb, 1);	/* LAPB internal control */
-	memcpy(skb_put(skb, count), sl->rbuff, count);
+	skb_put_data(skb, sl->rbuff, count);
 	skb->protocol = x25_type_trans(skb, sl->dev);
 	err = lapb_data_received(skb->dev, skb);
 	if (err != LAPB_OK) {