tipc: introduce node contact FSM

[cascardo/linux.git] / net / tipc / node.c

diff --git a/net/tipc/node.c b/net/tipc/node.c
index 77effb2..9dbbb5d 100644 (file)
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -141,7 +141,7 @@ struct tipc_node *tipc_node_create(struct net *net, u32 addr)
                        break;
        }
        list_add_tail_rcu(&n_ptr->list, &temp_node->list);
-       n_ptr->action_flags = TIPC_WAIT_PEER_LINKS_DOWN;
+       n_ptr->state = SELF_DOWN_PEER_DOWN;
        n_ptr->signature = INVALID_NODE_SIG;
        n_ptr->active_links[0] = INVALID_BEARER_ID;
        n_ptr->active_links[1] = INVALID_BEARER_ID;
@@ -421,8 +421,131 @@ void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
        }
 }
 
+/* tipc_node_fsm_evt - node finite state machine
+ * Determines when contact is allowed with peer node
+ */
+void tipc_node_fsm_evt(struct tipc_node *n, int evt)
+{
+       int state = n->state;
+
+       switch (state) {
+       case SELF_DOWN_PEER_DOWN:
+               switch (evt) {
+               case SELF_ESTABL_CONTACT_EVT:
+                       state = SELF_UP_PEER_COMING;
+                       break;
+               case PEER_ESTABL_CONTACT_EVT:
+                       state = SELF_COMING_PEER_UP;
+                       break;
+               case SELF_LOST_CONTACT_EVT:
+               case PEER_LOST_CONTACT_EVT:
+                       break;
+               default:
+                       pr_err("Unknown node fsm evt %x/%x\n", state, evt);
+               }
+               break;
+       case SELF_UP_PEER_UP:
+               switch (evt) {
+               case SELF_LOST_CONTACT_EVT:
+                       state = SELF_DOWN_PEER_LEAVING;
+                       break;
+               case PEER_LOST_CONTACT_EVT:
+                       state = SELF_LEAVING_PEER_DOWN;
+                       break;
+               case SELF_ESTABL_CONTACT_EVT:
+               case PEER_ESTABL_CONTACT_EVT:
+                       break;
+               default:
+                       pr_err("Unknown node fsm evt %x/%x\n", state, evt);
+               }
+               break;
+       case SELF_DOWN_PEER_LEAVING:
+               switch (evt) {
+               case PEER_LOST_CONTACT_EVT:
+                       state = SELF_DOWN_PEER_DOWN;
+                       break;
+               case SELF_ESTABL_CONTACT_EVT:
+               case PEER_ESTABL_CONTACT_EVT:
+               case SELF_LOST_CONTACT_EVT:
+                       break;
+               default:
+                       pr_err("Unknown node fsm evt %x/%x\n", state, evt);
+               }
+               break;
+       case SELF_UP_PEER_COMING:
+               switch (evt) {
+               case PEER_ESTABL_CONTACT_EVT:
+                       state = SELF_UP_PEER_UP;
+                       break;
+               case SELF_LOST_CONTACT_EVT:
+                       state = SELF_DOWN_PEER_LEAVING;
+                       break;
+               case SELF_ESTABL_CONTACT_EVT:
+               case PEER_LOST_CONTACT_EVT:
+                       break;
+               default:
+                       pr_err("Unknown node fsm evt %x/%x\n", state, evt);
+               }
+               break;
+       case SELF_COMING_PEER_UP:
+               switch (evt) {
+               case SELF_ESTABL_CONTACT_EVT:
+                       state = SELF_UP_PEER_UP;
+                       break;
+               case PEER_LOST_CONTACT_EVT:
+                       state = SELF_LEAVING_PEER_DOWN;
+                       break;
+               case SELF_LOST_CONTACT_EVT:
+               case PEER_ESTABL_CONTACT_EVT:
+                       break;
+               default:
+                       pr_err("Unknown node fsm evt %x/%x\n", state, evt);
+               }
+               break;
+       case SELF_LEAVING_PEER_DOWN:
+               switch (evt) {
+               case SELF_LOST_CONTACT_EVT:
+                       state = SELF_DOWN_PEER_DOWN;
+                       break;
+               case SELF_ESTABL_CONTACT_EVT:
+               case PEER_ESTABL_CONTACT_EVT:
+               case PEER_LOST_CONTACT_EVT:
+                       break;
+               default:
+                       pr_err("Unknown node fsm evt %x/%x\n", state, evt);
+               }
+               break;
+       default:
+               pr_err("Unknown node fsm state %x\n", state);
+               break;
+       }
+
+       n->state = state;
+}
+
+bool tipc_node_filter_skb(struct tipc_node *n, struct tipc_msg *hdr)
+{
+       int state = n->state;
+
+       if (likely(state == SELF_UP_PEER_UP))
+               return true;
+       if (state == SELF_DOWN_PEER_DOWN)
+               return true;
+       if (state == SELF_UP_PEER_COMING)
+               return true;
+       if (state == SELF_COMING_PEER_UP)
+               return true;
+       if (state == SELF_LEAVING_PEER_DOWN)
+               return false;
+       if (state == SELF_DOWN_PEER_LEAVING)
+               if (!msg_peer_is_up(hdr))
+                       return true;
+       return false;
+}
+
 static void node_established_contact(struct tipc_node *n_ptr)
 {
+       tipc_node_fsm_evt(n_ptr, SELF_ESTABL_CONTACT_EVT);
        n_ptr->action_flags |= TIPC_NOTIFY_NODE_UP;
        n_ptr->bclink.oos_state = 0;
        n_ptr->bclink.acked = tipc_bclink_get_last_sent(n_ptr->net);
@@ -468,11 +591,8 @@ static void node_lost_contact(struct tipc_node *n_ptr)
                l_ptr->failover_skb = NULL;
                tipc_link_reset_fragments(l_ptr);
        }
-
-       n_ptr->action_flags &= ~TIPC_WAIT_OWN_LINKS_DOWN;
-
        /* Prevent re-contact with node until cleanup is done */
-       n_ptr->action_flags |= TIPC_WAIT_PEER_LINKS_DOWN;
+       tipc_node_fsm_evt(n_ptr, SELF_LOST_CONTACT_EVT);
 
        /* Notify publications from this node */
        n_ptr->action_flags |= TIPC_NOTIFY_NODE_DOWN;