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, 2 insertions, 4 deletions

diff --git a/drivers/net/ppp/ppp_async.c b/drivers/net/ppp/ppp_async.c
index feb9569e3345..32c72db654e2 100644
--- a/drivers/net/ppp/ppp_async.c
+++ b/drivers/net/ppp/ppp_async.c
@@ -894,8 +894,7 @@ ppp_async_input(struct asyncppp *ap, const unsigned char *buf,
 				/* packet overflowed MRU */
 				ap->state |= SC_TOSS;
 			} else {
-				sp = skb_put(skb, n);
-				memcpy(sp, buf, n);
+				sp = skb_put_data(skb, buf, n);
 				if (ap->state & SC_ESCAPE) {
 					sp[0] ^= PPP_TRANS;
 					ap->state &= ~SC_ESCAPE;
diff --git a/drivers/net/ppp/ppp_synctty.c b/drivers/net/ppp/ppp_synctty.c
index 9ae53986cb4a..ce2300c0bcbf 100644
--- a/drivers/net/ppp/ppp_synctty.c
+++ b/drivers/net/ppp/ppp_synctty.c
@@ -697,8 +697,7 @@ ppp_sync_input(struct syncppp *ap, const unsigned char *buf,
 		goto err;
 	}
 
-	p = skb_put(skb, count);
-	memcpy(p, buf, count);
+	p = skb_put_data(skb, buf, count);
 
 	/* strip address/control field if present */
 	p = skb->data;