[NETLINK]: Introduce nlmsg_hdr() helper

For the common "(struct nlmsghdr *)skb->data" sequence, so that we reduce the
number of direct accesses to skb->data and for consistency with all the other
cast skb member helpers.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 68a632b372ec..36629fff26d3 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -138,6 +138,11 @@ struct nlattr
 #include <linux/capability.h>
 #include <linux/skbuff.h>
 
+static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb)
+{
+        return (struct nlmsghdr *)skb->data;
+}
+
 struct netlink_skb_parms
 {
         struct ucred            creds;          /* Skb credentials      */