1 files changed, 35 insertions, 0 deletions

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 1c514b64a0a9..f5cd986e1e50 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1705,6 +1705,41 @@ tnl:
         }
 }
 
+/**
+ * tipc_link_failover_prepare() - prepare tnl for link failover
+ *
+ * This is a special version of the precursor - tipc_link_tnl_prepare(),
+ * see the tipc_node_link_failover() for details
+ *
+ * @l: failover link
+ * @tnl: tunnel link
+ * @xmitq: queue for messages to be xmited
+ */
+void tipc_link_failover_prepare(struct tipc_link *l, struct tipc_link *tnl,
+                                struct sk_buff_head *xmitq)
+{
+        struct sk_buff_head *fdefq = &tnl->failover_deferdq;
+
+        tipc_link_create_dummy_tnl_msg(tnl, xmitq);
+
+        /* This failover link enpoint was never established before,
+         * so it has not received anything from peer.
+         * Otherwise, it must be a normal failover situation or the
+         * node has entered SELF_DOWN_PEER_LEAVING and both peer nodes
+         * would have to start over from scratch instead.
+         */
+        WARN_ON(l && tipc_link_is_up(l));
+        tnl->drop_point = 1;
+        tnl->failover_reasm_skb = NULL;
+
+        /* Initiate the link's failover deferdq */
+        if (unlikely(!skb_queue_empty(fdefq))) {
+                pr_warn("Link failover deferdq not empty: %d!\n",
+                        skb_queue_len(fdefq));
+                __skb_queue_purge(fdefq);
+        }
+}
+
 /* tipc_link_validate_msg(): validate message against current link state
  * Returns true if message should be accepted, otherwise false
  */