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, 9 insertions, 16 deletions

diff --git a/drivers/staging/gdm724x/gdm_lte.c b/drivers/staging/gdm724x/gdm_lte.c
index cf809987f79f..9ab6ce231f11 100644
--- a/drivers/staging/gdm724x/gdm_lte.c
+++ b/drivers/staging/gdm724x/gdm_lte.c
@@ -161,12 +161,9 @@ static int gdm_lte_emulate_arp(struct sk_buff *skb_in, u32 nic_type)
 		return -ENOMEM;
 	skb_reserve(skb_out, NET_IP_ALIGN);
 
-	memcpy(skb_put(skb_out, mac_header_len), mac_header_data,
-	       mac_header_len);
-	memcpy(skb_put(skb_out, sizeof(struct arphdr)), arp_out,
-	       sizeof(struct arphdr));
-	memcpy(skb_put(skb_out, sizeof(struct arpdata)), arp_data_out,
-	       sizeof(struct arpdata));
+	skb_put_data(skb_out, mac_header_data, mac_header_len);
+	skb_put_data(skb_out, arp_out, sizeof(struct arphdr));
+	skb_put_data(skb_out, arp_data_out, sizeof(struct arpdata));
 
 	skb_out->protocol = ((struct ethhdr *)mac_header_data)->h_proto;
 	skb_out->dev = skb_in->dev;
@@ -322,14 +319,10 @@ static int gdm_lte_emulate_ndp(struct sk_buff *skb_in, u32 nic_type)
 		return -ENOMEM;
 	skb_reserve(skb_out, NET_IP_ALIGN);
 
-	memcpy(skb_put(skb_out, mac_header_len), mac_header_data,
-	       mac_header_len);
-	memcpy(skb_put(skb_out, sizeof(struct ipv6hdr)), &ipv6_out,
-	       sizeof(struct ipv6hdr));
-	memcpy(skb_put(skb_out, sizeof(struct icmp6hdr)), &icmp6_out,
-	       sizeof(struct icmp6hdr));
-	memcpy(skb_put(skb_out, sizeof(struct neighbour_advertisement)), &na,
-	       sizeof(struct neighbour_advertisement));
+	skb_put_data(skb_out, mac_header_data, mac_header_len);
+	skb_put_data(skb_out, &ipv6_out, sizeof(struct ipv6hdr));
+	skb_put_data(skb_out, &icmp6_out, sizeof(struct icmp6hdr));
+	skb_put_data(skb_out, &na, sizeof(struct neighbour_advertisement));
 
 	skb_out->protocol = ((struct ethhdr *)mac_header_data)->h_proto;
 	skb_out->dev = skb_in->dev;
@@ -669,8 +662,8 @@ static void gdm_lte_netif_rx(struct net_device *dev, char *buf,
 		return;
 	skb_reserve(skb, NET_IP_ALIGN);
 
-	memcpy(skb_put(skb, mac_header_len), mac_header_data, mac_header_len);
-	memcpy(skb_put(skb, len), buf, len);
+	skb_put_data(skb, mac_header_data, mac_header_len);
+	skb_put_data(skb, buf, len);
 
 	skb->protocol = ((struct ethhdr *)mac_header_data)->h_proto;
 	skb->dev = dev;