tipc: let neighbor discoverer tranmsit consumable buffers

The neighbor discovery function currently uses the function
tipc_bearer_send() for transmitting packets, assuming that the
sent buffers are not consumed by the called function.

We want to change this, in order to avoid unnecessary buffer cloning
elswhere in the code.

This commit introduces a new function tipc_bearer_skb() which consumes
the sent buffers, and let the discoverer functions use this new call
instead. The discoverer does now itself perform the cloning when
that is necessary.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index b39f631..1133391 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -477,6 +477,24 @@
 	return mtu;
 }
 
+/* tipc_bearer_xmit_skb - sends buffer to destination over bearer
+ */
+void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id,
+			  struct sk_buff *skb,
+			  struct tipc_media_addr *dest)
+{
+	struct tipc_net *tn = tipc_net(net);
+	struct tipc_bearer *b;
+
+	rcu_read_lock();
+	b = rcu_dereference_rtnl(tn->bearer_list[bearer_id]);
+	if (likely(b))
+		b->media->send_msg(net, skb, b, dest);
+	rcu_read_unlock();
+	/* Until we remove cloning in tipc_l2_send_msg(): */
+	kfree_skb(skb);
+}
+
 /* tipc_bearer_xmit() -send buffer to destination over bearer
  */
 void tipc_bearer_xmit(struct net *net, u32 bearer_id,