From 59ae1d127ac0ae404baf414c434ba2651b793f46 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Fri, 16 Jun 2017 14:29:20 +0200
Subject: 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>
---
 lib/nlattr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'lib')

diff --git a/lib/nlattr.c b/lib/nlattr.c
index d09d9746fc5d..ab15a6c095d3 100644
--- a/lib/nlattr.c
+++ b/lib/nlattr.c
@@ -616,7 +616,7 @@ int nla_append(struct sk_buff *skb, int attrlen, const void *data)
 	if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
 		return -EMSGSIZE;
 
-	memcpy(skb_put(skb, attrlen), data, attrlen);
+	skb_put_data(skb, data, attrlen);
 	return 0;
 }
 EXPORT_SYMBOL(nla_append);
-- 
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