[NETLINK]: Do precise netlink message allocations where possible

Account for the netlink message header size directly in nlmsg_new()
instead of relying on the caller calculate it correctly.

Replaces error handling of message construction functions when
constructing notifications with bug traps since a failure implies
a bug in calculating the size of the skb.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 4 deletions

diff --git a/include/net/netlink.h b/include/net/netlink.h
index ce5cba19c393..30021339157c 100644
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -500,14 +500,15 @@ static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
 
 /**
  * nlmsg_new - Allocate a new netlink message
- * @size: maximum size of message
+ * @payload: size of the message payload
  * @flags: the type of memory to allocate.
  *
- * Use NLMSG_GOODSIZE if size isn't know and you need a good default size.
+ * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
+ * and a good default is needed.
  */
-static inline struct sk_buff *nlmsg_new(int size, gfp_t flags)
+static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
 {
-        return alloc_skb(size, flags);
+        return alloc_skb(nlmsg_total_size(payload), flags);
 }
 
 /**