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>

4 files changed, 5 insertions, 9 deletions

diff --git a/drivers/net/caif/caif_hsi.c b/drivers/net/caif/caif_hsi.c
index 71a7c3b44fdd..4534326e20ac 100644
--- a/drivers/net/caif/caif_hsi.c
+++ b/drivers/net/caif/caif_hsi.c
@@ -454,8 +454,7 @@ static int cfhsi_rx_desc(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
 		}
 		caif_assert(skb != NULL);
 
-		dst = skb_put(skb, len);
-		memcpy(dst, pfrm, len);
+		dst = skb_put_data(skb, pfrm, len);
 
 		skb->protocol = htons(ETH_P_CAIF);
 		skb_reset_mac_header(skb);
@@ -585,8 +584,7 @@ static int cfhsi_rx_pld(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
 		}
 		caif_assert(skb != NULL);
 
-		dst = skb_put(skb, len);
-		memcpy(dst, pcffrm, len);
+		dst = skb_put_data(skb, pcffrm, len);
 
 		skb->protocol = htons(ETH_P_CAIF);
 		skb_reset_mac_header(skb);
diff --git a/drivers/net/caif/caif_serial.c b/drivers/net/caif/caif_serial.c
index 76e1d3545105..5c57be2082ba 100644
--- a/drivers/net/caif/caif_serial.c
+++ b/drivers/net/caif/caif_serial.c
@@ -198,8 +198,7 @@ static void ldisc_receive(struct tty_struct *tty, const u8 *data,
 	skb = netdev_alloc_skb(ser->dev, count+1);
 	if (skb == NULL)
 		return;
-	p = skb_put(skb, count);
-	memcpy(p, data, count);
+	p = skb_put_data(skb, data, count);
 
 	skb->protocol = htons(ETH_P_CAIF);
 	skb_reset_mac_header(skb);
diff --git a/drivers/net/caif/caif_spi.c b/drivers/net/caif/caif_spi.c
index fc21afe852b9..24a5f5ca2037 100644
--- a/drivers/net/caif/caif_spi.c
+++ b/drivers/net/caif/caif_spi.c
@@ -548,8 +548,7 @@ int cfspi_rxfrm(struct cfspi *cfspi, u8 *buf, size_t len)
 		skb = netdev_alloc_skb(cfspi->ndev, pkt_len + 1);
 		caif_assert(skb != NULL);
 
-		dst = skb_put(skb, pkt_len);
-		memcpy(dst, src, pkt_len);
+		dst = skb_put_data(skb, src, pkt_len);
 		src += pkt_len;
 
 		skb->protocol = htons(ETH_P_CAIF);
diff --git a/drivers/net/caif/caif_virtio.c b/drivers/net/caif/caif_virtio.c
index 1794ea0420b7..c3d104feee13 100644
--- a/drivers/net/caif/caif_virtio.c
+++ b/drivers/net/caif/caif_virtio.c
@@ -242,7 +242,7 @@ static struct sk_buff *cfv_alloc_and_copy_skb(int *err,
 
 	skb_reserve(skb, cfv->rx_hr + pad_len);
 
-	memcpy(skb_put(skb, cfpkt_len), frm + cfv->rx_hr, cfpkt_len);
+	skb_put_data(skb, frm + cfv->rx_hr, cfpkt_len);
 	return skb;
 }