tipc: move link creation from neighbor discoverer to node

As a step towards turning links into node internal entities, we move the
creation of links from the neighbor discovery logics to the node's link
control logics.

We also create an additional entry for the link's media address in the
newly introduced struct tipc_link_entry, since this is where it is
needed in the upcoming commits. The current copy in struct tipc_link
is kept for now, but will be removed later.

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/discover.c b/net/tipc/discover.c
index 9334453..164d089 100644
--- a/net/tipc/discover.c
+++ b/net/tipc/discover.c
@@ -35,7 +35,7 @@
  */
 
 #include "core.h"
-#include "link.h"
+#include "node.h"
 #include "discover.h"
 
 /* min delay during bearer start up */
@@ -125,7 +125,6 @@
 {
 	struct tipc_net *tn = net_generic(net, tipc_net_id);
 	struct tipc_node *node;
-	struct tipc_link *link;
 	struct tipc_media_addr maddr;
 	struct sk_buff *rbuf;
 	struct tipc_msg *msg = buf_msg(buf);
@@ -170,13 +169,10 @@
 		return;
 	tipc_node_lock(node);
 	node->capabilities = caps;
-	link = node->links[bearer->identity].link;
 
 	/* Prepare to validate requesting node's signature and media address */
 	sign_match = (signature == node->signature);
-	addr_match = link && !memcmp(&link->media_addr, &maddr, sizeof(maddr));
-	link_up = link && tipc_link_is_up(link);
-
+	tipc_node_check_dest(node, bearer, &link_up, &addr_match, &maddr);
 
 	/* These three flags give us eight permutations: */
 
@@ -239,16 +235,8 @@
 	if (accept_sign)
 		node->signature = signature;
 
-	if (accept_addr) {
-		if (!link)
-			link = tipc_link_create(node, bearer, &maddr);
-		if (link) {
-			memcpy(&link->media_addr, &maddr, sizeof(maddr));
-			tipc_link_reset(link);
-		} else {
-			respond = false;
-		}
-	}
+	if (accept_addr && !tipc_node_update_dest(node, bearer, &maddr))
+		respond = false;
 
 	/* Send response, if necessary */
 	if (respond && (mtyp == DSC_REQ_MSG)) {