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>

net/bluetooth/cmtp/core.c

@@ -122,7 +122,7 @@ static inline void cmtp_add_msgpart(struct cmtp_session *session, int id, const
 	if (skb && (skb->len > 0))
 		skb_copy_from_linear_data(skb, skb_put(nskb, skb->len), skb->len);
 
-	memcpy(skb_put(nskb, count), buf, count);
+	skb_put_data(nskb, buf, count);
 
 	session->reassembly[id] = nskb;
 

net/bluetooth/hci_core.c

@@ -3266,7 +3266,7 @@ int hci_reset_dev(struct hci_dev *hdev)
 		return -ENOMEM;
 
 	hci_skb_pkt_type(skb) = HCI_EVENT_PKT;
-	memcpy(skb_put(skb, 3), hw_err, 3);
+	skb_put_data(skb, hw_err, 3);
 
 	/* Send Hardware Error to upper stack */
 	return hci_recv_frame(hdev, skb);

net/bluetooth/hci_request.c

@@ -304,7 +304,7 @@ struct sk_buff *hci_prepare_cmd(struct hci_dev *hdev, u16 opcode, u32 plen,
 	hdr->plen   = plen;
 
 	if (plen)
-		memcpy(skb_put(skb, plen), param, plen);
+		skb_put_data(skb, param, plen);
 
 	BT_DBG("skb len %d", skb->len);
 

net/bluetooth/hci_sock.c

@@ -379,7 +379,7 @@ void hci_send_monitor_ctrl_event(struct hci_dev *hdev, u16 event,
 		put_unaligned_le16(event, skb_put(skb, 2));
 
 		if (data)
-			memcpy(skb_put(skb, data_len), data, data_len);
+			skb_put_data(skb, data, data_len);
 
 		skb->tstamp = tstamp;
 
@@ -515,10 +515,10 @@ static struct sk_buff *create_monitor_ctrl_open(struct sock *sk)
 
 	put_unaligned_le32(hci_pi(sk)->cookie, skb_put(skb, 4));
 	put_unaligned_le16(format, skb_put(skb, 2));
-	memcpy(skb_put(skb, sizeof(ver)), ver, sizeof(ver));
+	skb_put_data(skb, ver, sizeof(ver));
 	put_unaligned_le32(flags, skb_put(skb, 4));
 	*skb_put(skb, 1) = TASK_COMM_LEN;
-	memcpy(skb_put(skb, TASK_COMM_LEN), hci_pi(sk)->comm, TASK_COMM_LEN);
+	skb_put_data(skb, hci_pi(sk)->comm, TASK_COMM_LEN);
 
 	__net_timestamp(skb);
 
@@ -586,7 +586,7 @@ static struct sk_buff *create_monitor_ctrl_command(struct sock *sk, u16 index,
 	put_unaligned_le16(opcode, skb_put(skb, 2));
 
 	if (buf)
-		memcpy(skb_put(skb, len), buf, len);
+		skb_put_data(skb, buf, len);
 
 	__net_timestamp(skb);
 

net/bluetooth/hidp/core.c

@@ -114,7 +114,7 @@ static int hidp_send_message(struct hidp_session *session, struct socket *sock,
 
 	*skb_put(skb, 1) = hdr;
 	if (data && size > 0)
-		memcpy(skb_put(skb, size), data, size);
+		skb_put_data(skb, data, size);
 
 	skb_queue_tail(transmit, skb);
 	wake_up_interruptible(sk_sleep(sk));

net/bluetooth/l2cap_core.c

@@ -2923,7 +2923,7 @@ static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn, u8 code,
 
 	if (dlen) {
 		count -= L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE;
-		memcpy(skb_put(skb, count), data, count);
+		skb_put_data(skb, data, count);
 		data += count;
 	}
 
@@ -2938,7 +2938,7 @@ static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn, u8 code,
 		if (!*frag)
 			goto fail;
 
-		memcpy(skb_put(*frag, count), data, count);
+		skb_put_data(*frag, data, count);
 
 		len  -= count;
 		data += count;

net/bluetooth/mgmt_util.c

@@ -44,7 +44,7 @@ static struct sk_buff *create_monitor_ctrl_event(__le16 index, u32 cookie,
 	put_unaligned_le16(opcode, skb_put(skb, 2));
 
 	if (buf)
-		memcpy(skb_put(skb, len), buf, len);
+		skb_put_data(skb, buf, len);
 
 	__net_timestamp(skb);
 
@@ -75,7 +75,7 @@ int mgmt_send_event(u16 event, struct hci_dev *hdev, unsigned short channel,
 	hdr->len = cpu_to_le16(data_len);
 
 	if (data)
-		memcpy(skb_put(skb, data_len), data, data_len);
+		skb_put_data(skb, data, data_len);
 
 	/* Time stamp */
 	__net_timestamp(skb);

net/bluetooth/rfcomm/tty.c

@@ -798,7 +798,7 @@ static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, in
 
 		skb_reserve(skb, RFCOMM_SKB_HEAD_RESERVE);
 
-		memcpy(skb_put(skb, size), buf + sent, size);
+		skb_put_data(skb, buf + sent, size);
 
 		rfcomm_dlc_send_noerror(dlc, skb);