networking: add and use skb_put_u8()

Joe and Bjørn suggested that it'd be nicer to not have the
cast in the fairly common case of doing
	*(u8 *)skb_put(skb, 1) = c;

Add skb_put_u8() for this case, and use it across the code,
using the following spatch:

    @@
    expression SKB, C, S;
    typedef u8;
    identifier fn = {skb_put};
    fresh identifier fn2 = fn ## "_u8";
    @@
    - *(u8 *)fn(SKB, S) = C;
    + fn2(SKB, C);

Note that due to the "S", the spatch isn't perfect, it should
have checked that S is 1, but there's also places that use a
sizeof expression like sizeof(var) or sizeof(u8) etc. Turns
out that nobody ever did something like
	*(u8 *)skb_put(skb, 2) = c;

which would be wrong anyway since the second byte wouldn't be
initialized.

Suggested-by: Joe Perches <joe@perches.com>
Suggested-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 6 deletions

diff --git a/net/decnet/dn_nsp_out.c b/net/decnet/dn_nsp_out.c
index 7e054b2f270a..66f035e476ea 100644
--- a/net/decnet/dn_nsp_out.c
+++ b/net/decnet/dn_nsp_out.c
@@ -530,7 +530,7 @@ void dn_send_conn_conf(struct sock *sk, gfp_t gfp)
 	msg->info = scp->info_loc;
 	msg->segsize = cpu_to_le16(scp->segsize_loc);
 
-	*(u8 *)skb_put(skb, 1) = len;
+	skb_put_u8(skb, len);
 
 	if (len > 0)
 		skb_put_data(skb, scp->conndata_out.opt_data, len);
@@ -686,25 +686,25 @@ void dn_nsp_send_conninit(struct sock *sk, unsigned char msgflg)
 	if (scp->peer.sdn_flags & SDF_UICPROXY)
 		menuver |= DN_MENUVER_UIC;
 
-	*(u8 *)skb_put(skb, 1) = menuver;	/* Menu Version		*/
+	skb_put_u8(skb, menuver);	/* Menu Version		*/
 
 	aux = scp->accessdata.acc_userl;
-	*(u8 *)skb_put(skb, 1) = aux;
+	skb_put_u8(skb, aux);
 	if (aux > 0)
 		skb_put_data(skb, scp->accessdata.acc_user, aux);
 
 	aux = scp->accessdata.acc_passl;
-	*(u8 *)skb_put(skb, 1) = aux;
+	skb_put_u8(skb, aux);
 	if (aux > 0)
 		skb_put_data(skb, scp->accessdata.acc_pass, aux);
 
 	aux = scp->accessdata.acc_accl;
-	*(u8 *)skb_put(skb, 1) = aux;
+	skb_put_u8(skb, aux);
 	if (aux > 0)
 		skb_put_data(skb, scp->accessdata.acc_acc, aux);
 
 	aux = (__u8)le16_to_cpu(scp->conndata_out.opt_optl);
-	*(u8 *)skb_put(skb, 1) = aux;
+	skb_put_u8(skb, aux);
 	if (aux > 0)
 		skb_put_data(skb, scp->conndata_out.opt_data, aux);