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, 6 insertions, 11 deletions

diff --git a/net/nfc/digital_dep.c b/net/nfc/digital_dep.c
index f864ce1..f44f75a 100644
--- a/net/nfc/digital_dep.c
+++ b/net/nfc/digital_dep.c
@@ -226,8 +226,7 @@ digital_send_dep_data_prep(struct nfc_digital_dev *ddev, struct sk_buff *skb,
 			return ERR_PTR(-ENOMEM);
 		}
 
-		memcpy(skb_put(new_skb, ddev->remote_payload_max), skb->data,
-		       ddev->remote_payload_max);
+		skb_put_data(new_skb, skb->data, ddev->remote_payload_max);
 		skb_pull(skb, ddev->remote_payload_max);
 
 		ddev->chaining_skb = skb;
@@ -277,8 +276,7 @@ digital_recv_dep_data_gather(struct nfc_digital_dev *ddev, u8 pfb,
 			ddev->chaining_skb = new_skb;
 		}
 
-		memcpy(skb_put(ddev->chaining_skb, resp->len), resp->data,
-		       resp->len);
+		skb_put_data(ddev->chaining_skb, resp->data, resp->len);
 
 		kfree_skb(resp);
 		resp = NULL;
@@ -525,7 +523,7 @@ int digital_in_send_atr_req(struct nfc_digital_dev *ddev,
 
 	if (gb_len) {
 		atr_req->pp |= DIGITAL_GB_BIT;
-		memcpy(skb_put(skb, gb_len), gb, gb_len);
+		skb_put_data(skb, gb, gb_len);
 	}
 
 	digital_skb_push_dep_sod(ddev, skb);
@@ -1012,8 +1010,7 @@ static int digital_tg_send_ack(struct nfc_digital_dev *ddev,
 	if (ddev->did) {
 		dep_res->pfb |= DIGITAL_NFC_DEP_PFB_DID_BIT;
 
-		memcpy(skb_put(skb, sizeof(ddev->did)), &ddev->did,
-		       sizeof(ddev->did));
+		skb_put_data(skb, &ddev->did, sizeof(ddev->did));
 	}
 
 	ddev->curr_nfc_dep_pni =
@@ -1057,8 +1054,7 @@ static int digital_tg_send_atn(struct nfc_digital_dev *ddev)
 	if (ddev->did) {
 		dep_res->pfb |= DIGITAL_NFC_DEP_PFB_DID_BIT;
 
-		memcpy(skb_put(skb, sizeof(ddev->did)), &ddev->did,
-		       sizeof(ddev->did));
+		skb_put_data(skb, &ddev->did, sizeof(ddev->did));
 	}
 
 	digital_skb_push_dep_sod(ddev, skb);
@@ -1325,8 +1321,7 @@ int digital_tg_send_dep_res(struct nfc_digital_dev *ddev, struct sk_buff *skb)
 	if (ddev->did) {
 		dep_res->pfb |= DIGITAL_NFC_DEP_PFB_DID_BIT;
 
-		memcpy(skb_put(skb, sizeof(ddev->did)), &ddev->did,
-		       sizeof(ddev->did));
+		skb_put_data(skb, &ddev->did, sizeof(ddev->did));
 	}
 
 	ddev->curr_nfc_dep_pni =