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, 8 insertions, 7 deletions

diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 61fff422424f..17b9f1ce23db 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -462,7 +462,7 @@ int nci_nfcc_loopback(struct nci_dev *ndev, void *data, size_t data_len,
 		return -ENOMEM;
 
 	skb_reserve(skb, NCI_DATA_HDR_SIZE);
-	memcpy(skb_put(skb, data_len), data, data_len);
+	skb_put_data(skb, data, data_len);
 
 	loopback_data.conn_id = conn_id;
 	loopback_data.data = skb;
@@ -1350,7 +1350,7 @@ int nci_send_cmd(struct nci_dev *ndev, __u16 opcode, __u8 plen, void *payload)
 	nci_pbf_set((__u8 *)hdr, NCI_PBF_LAST);
 
 	if (plen)
-		memcpy(skb_put(skb, plen), payload, plen);
+		skb_put_data(skb, payload, plen);
 
 	skb_queue_tail(&ndev->cmd_q, skb);
 	queue_work(ndev->cmd_wq, &ndev->cmd_work);
diff --git a/net/nfc/nci/data.c b/net/nfc/nci/data.c
index dbd24254412a..2488d9241f1d 100644
--- a/net/nfc/nci/data.c
+++ b/net/nfc/nci/data.c
@@ -138,7 +138,7 @@ static int nci_queue_tx_data_frags(struct nci_dev *ndev,
 		skb_reserve(skb_frag, NCI_DATA_HDR_SIZE);
 
 		/* first, copy the data */
-		memcpy(skb_put(skb_frag, frag_len), data, frag_len);
+		skb_put_data(skb_frag, data, frag_len);
 
 		/* second, set the header */
 		nci_push_data_hdr(ndev, conn_id, skb_frag,
diff --git a/net/nfc/nci/hci.c b/net/nfc/nci/hci.c
index a0ab26d535dc..d4a53ce818c3 100644
--- a/net/nfc/nci/hci.c
+++ b/net/nfc/nci/hci.c
@@ -187,7 +187,7 @@ static int nci_hci_send_data(struct nci_dev *ndev, u8 pipe,
 		*skb_push(skb, 1) = cb;
 
 		if (len > 0)
-			memcpy(skb_put(skb, len), data + i, len);
+			skb_put_data(skb, data + i, len);
 
 		r = nci_send_data(ndev, conn_info->conn_id, skb);
 		if (r < 0)
@@ -476,8 +476,9 @@ void nci_hci_data_received_cb(void *context,
 
 		skb_queue_walk(&ndev->hci_dev->rx_hcp_frags, frag_skb) {
 			msg_len = frag_skb->len - NCI_HCI_HCP_PACKET_HEADER_LEN;
-			memcpy(skb_put(hcp_skb, msg_len), frag_skb->data +
-			       NCI_HCI_HCP_PACKET_HEADER_LEN, msg_len);
+			skb_put_data(hcp_skb,
+				     frag_skb->data + NCI_HCI_HCP_PACKET_HEADER_LEN,
+				     msg_len);
 		}
 
 		skb_queue_purge(&ndev->hci_dev->rx_hcp_frags);
diff --git a/net/nfc/nci/uart.c b/net/nfc/nci/uart.c
index c468eabd6943..cfa7f352c1c3 100644
--- a/net/nfc/nci/uart.c
+++ b/net/nfc/nci/uart.c
@@ -371,7 +371,7 @@ static int nci_uart_default_recv_buf(struct nci_uart *nu, const u8 *data,
 		chunk_len = nu->rx_packet_len - nu->rx_skb->len;
 		if (count < chunk_len)
 			chunk_len = count;
-		memcpy(skb_put(nu->rx_skb, chunk_len), data, chunk_len);
+		skb_put_data(nu->rx_skb, data, chunk_len);
 		data += chunk_len;
 		count -= chunk_len;