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>

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 @@ void tipc_disc_rcv(struct net *net, struct sk_buff *buf,
 {
 	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 @@ void tipc_disc_rcv(struct net *net, struct sk_buff *buf,
 		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));
+	tipc_node_check_dest(node, bearer, &link_up, &addr_match, &maddr);
-	link_up = link && tipc_link_is_up(link);
-
 
 	/* These three flags give us eight permutations: */
 
@@ -239,16 +235,8 @@ void tipc_disc_rcv(struct net *net, struct sk_buff *buf,
 	if (accept_sign)
 		node->signature = signature;
 
-	if (accept_addr) {
+	if (accept_addr && !tipc_node_update_dest(node, bearer, &maddr))
-		if (!link)
+		respond = false;
-			link = tipc_link_create(node, bearer, &maddr);
-		if (link) {
-			memcpy(&link->media_addr, &maddr, sizeof(maddr));
-			tipc_link_reset(link);
-		} else {
-			respond = false;
-		}
-	}
 
 	/* Send response, if necessary */
 	if (respond && (mtyp == DSC_REQ_MSG)) {

net/tipc/node.c

@@ -334,6 +334,33 @@ bool tipc_node_is_up(struct tipc_node *n)
 	return n->active_links[0];
 }
 
+void tipc_node_check_dest(struct tipc_node *n, struct tipc_bearer *b,
+			  bool *link_up, bool *addr_match,
+			  struct tipc_media_addr *maddr)
+{
+	struct tipc_link *l = n->links[b->identity].link;
+	struct tipc_media_addr *curr = &n->links[b->identity].maddr;
+
+	*link_up = l && tipc_link_is_up(l);
+	*addr_match = l && !memcmp(curr, maddr, sizeof(*maddr));
+}
+
+bool tipc_node_update_dest(struct tipc_node *n,  struct tipc_bearer *b,
+			   struct tipc_media_addr *maddr)
+{
+	struct tipc_link *l = n->links[b->identity].link;
+	struct tipc_media_addr *curr = &n->links[b->identity].maddr;
+
+	if (!l)
+		l = tipc_link_create(n, b, maddr);
+	if (!l)
+		return false;
+	memcpy(&l->media_addr, maddr, sizeof(*maddr));
+	memcpy(curr, maddr, sizeof(*maddr));
+	tipc_link_reset(l);
+	return true;
+}
+
 void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 {
 	n_ptr->links[l_ptr->bearer_id].link = l_ptr;

net/tipc/node.h

@@ -92,6 +92,7 @@ struct tipc_node_bclink {
 struct tipc_link_entry {
 	struct tipc_link *link;
 	u32 mtu;
+	struct tipc_media_addr maddr;
 };
 
 /**
@@ -143,6 +144,11 @@ struct tipc_node *tipc_node_find(struct net *net, u32 addr);
 void tipc_node_put(struct tipc_node *node);
 struct tipc_node *tipc_node_create(struct net *net, u32 addr);
 void tipc_node_stop(struct net *net);
+void tipc_node_check_dest(struct tipc_node *n, struct tipc_bearer *bearer,
+			  bool *link_up, bool *addr_match,
+			  struct tipc_media_addr *maddr);
+bool tipc_node_update_dest(struct tipc_node *n, struct tipc_bearer *bearer,
+			   struct tipc_media_addr *maddr);
 void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr);
 void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr);
 void tipc_node_link_down(struct tipc_node *n_ptr, int bearer_id);