[PATCH] per-task-delay-accounting: utilities for genetlink usage

Two utilities for simplifying usage of NETLINK_GENERIC interface.
Signed-off-by: NBalbir Singh <balbir@in.ibm.com>
Signed-off-by: NShailabh Nagar <nagar@watson.ibm.com>
Cc: Jes Sorensen <jes@sgi.com>
Cc: Peter Chubb <peterc@gelato.unsw.edu.au>
Cc: Erich Focht <efocht@ess.nec.de>
Cc: Levent Serinol <lserinol@gmail.com>
Cc: Jay Lan <jlan@engr.sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

include/net/genetlink.h

@@ -150,4 +150,24 @@ static inline int genlmsg_unicast(struct sk_buff *skb, u32 pid)
 	return nlmsg_unicast(genl_sock, skb, pid);
 }
 
+/**
+ * gennlmsg_data - head of message payload
+ * @gnlh: genetlink messsage header
+ */
+static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
+{
+	return ((unsigned char *) gnlh + GENL_HDRLEN);
+}
+
+/**
+ * genlmsg_len - length of message payload
+ * @gnlh: genetlink message header
+ */
+static inline int genlmsg_len(const struct genlmsghdr *gnlh)
+{
+	struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
+							NLMSG_HDRLEN);
+	return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
+}
+
 #endif	/* __NET_GENERIC_NETLINK_H */