3 files changed, 49 insertions, 23 deletions

diff --git a/net/tipc/link.c b/net/tipc/link.c
index e7c608631276..8c794c1dd531 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -125,6 +125,11 @@ bool tipc_link_is_reset(struct tipc_link *l)
         return l->state & (LINK_RESET | LINK_FAILINGOVER | LINK_ESTABLISHING);
 }
 
+bool tipc_link_is_establishing(struct tipc_link *l)
+{
+        return l->state == LINK_ESTABLISHING;
+}
+
 bool tipc_link_is_synching(struct tipc_link *l)
 {
         return l->state == LINK_SYNCHING;
@@ -321,14 +326,15 @@ int tipc_link_fsm_evt(struct tipc_link *l, int evt)
                 switch (evt) {
                 case LINK_ESTABLISH_EVT:
                         l->state = LINK_ESTABLISHED;
-                        rc |= TIPC_LINK_UP_EVT;
                         break;
                 case LINK_FAILOVER_BEGIN_EVT:
                         l->state = LINK_FAILINGOVER;
                         break;
-                case LINK_PEER_RESET_EVT:
                 case LINK_RESET_EVT:
+                        l->state = LINK_RESET;
+                        break;
                 case LINK_FAILURE_EVT:
+                case LINK_PEER_RESET_EVT:
                 case LINK_SYNCH_BEGIN_EVT:
                 case LINK_FAILOVER_END_EVT:
                         break;
@@ -1091,9 +1097,9 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
                         return tipc_link_proto_rcv(l, skb, xmitq);
 
                 if (unlikely(!link_is_up(l))) {
-                        rc = tipc_link_fsm_evt(l, LINK_ESTABLISH_EVT);
-                        if (!link_is_up(l))
-                                goto drop;
+                        if (l->state == LINK_ESTABLISHING)
+                                rc = TIPC_LINK_UP_EVT;
+                        goto drop;
                 }
 
                 /* Don't send probe at next timeout expiration */
@@ -1338,6 +1344,7 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
         u16 peers_tol = msg_link_tolerance(hdr);
         u16 peers_prio = msg_linkprio(hdr);
         u16 rcv_nxt = l->rcv_nxt;
+        int mtyp = msg_type(hdr);
         char *if_name;
         int rc = 0;
 
@@ -1347,7 +1354,7 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
         if (link_own_addr(l) > msg_prevnode(hdr))
                 l->net_plane = msg_net_plane(hdr);
 
-        switch (msg_type(hdr)) {
+        switch (mtyp) {
         case RESET_MSG:
 
                 /* Ignore duplicate RESET with old session number */
@@ -1374,12 +1381,14 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
                 if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
                         l->priority = peers_prio;
 
-                if (msg_type(hdr) == RESET_MSG) {
-                        rc |= tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
-                } else if (!link_is_up(l)) {
-                        tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
-                        rc |= tipc_link_fsm_evt(l, LINK_ESTABLISH_EVT);
-                }
+                /* ACTIVATE_MSG serves as PEER_RESET if link is already down */
+                if ((mtyp == RESET_MSG) || !link_is_up(l))
+                        rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
+
+                /* ACTIVATE_MSG takes up link if it was already locally reset */
+                if ((mtyp == ACTIVATE_MSG) && (l->state == LINK_ESTABLISHING))
+                        rc = TIPC_LINK_UP_EVT;
+
                 l->peer_session = msg_session(hdr);
                 l->peer_bearer_id = msg_bearer_id(hdr);
                 if (l->mtu > msg_max_pkt(hdr))
@@ -1396,9 +1405,12 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
                 l->stats.recv_states++;
                 if (msg_probe(hdr))
                         l->stats.recv_probes++;
-                rc = tipc_link_fsm_evt(l, LINK_ESTABLISH_EVT);
-                if (!link_is_up(l))
+
+                if (!link_is_up(l)) {
+                        if (l->state == LINK_ESTABLISHING)
+                                rc = TIPC_LINK_UP_EVT;
                         break;
+                }
 
                 /* Send NACK if peer has sent pkts we haven't received yet */
                 if (more(peers_snd_nxt, rcv_nxt) && !tipc_link_is_synching(l))
diff --git a/net/tipc/link.h b/net/tipc/link.h
index 7a1ad4294b7a..d42dfc0e7bf5 100644
--- a/net/tipc/link.h
+++ b/net/tipc/link.h
@@ -217,6 +217,7 @@ int tipc_link_fsm_evt(struct tipc_link *l, int evt);
 void tipc_link_reset_fragments(struct tipc_link *l_ptr);
 bool tipc_link_is_up(struct tipc_link *l);
 bool tipc_link_is_reset(struct tipc_link *l);
+bool tipc_link_is_establishing(struct tipc_link *l);
 bool tipc_link_is_synching(struct tipc_link *l);
 bool tipc_link_is_failingover(struct tipc_link *l);
 bool tipc_link_is_blocked(struct tipc_link *l);
diff --git a/net/tipc/node.c b/net/tipc/node.c
index 703875fd6cde..656b5791f1a5 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -317,7 +317,11 @@ static void __tipc_node_link_up(struct tipc_node *n, int bearer_id,
         struct tipc_link *ol = node_active_link(n, 0);
         struct tipc_link *nl = n->links[bearer_id].link;
 
-        if (!nl || !tipc_link_is_up(nl))
+        if (!nl)
+                return;
+
+        tipc_link_fsm_evt(nl, LINK_ESTABLISH_EVT);
+        if (!tipc_link_is_up(nl))
                 return;
 
         n->working_links++;
@@ -437,17 +441,26 @@ static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
 static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
 {
         struct tipc_link_entry *le = &n->links[bearer_id];
+        struct tipc_link *l = le->link;
         struct tipc_media_addr *maddr;
         struct sk_buff_head xmitq;
 
+        if (!l)
+                return;
+
         __skb_queue_head_init(&xmitq);
 
         tipc_node_lock(n);
-        __tipc_node_link_down(n, &bearer_id, &xmitq, &maddr);
-        if (delete && le->link) {
-                kfree(le->link);
-                le->link = NULL;
-                n->link_cnt--;
+        if (!tipc_link_is_establishing(l)) {
+                __tipc_node_link_down(n, &bearer_id, &xmitq, &maddr);
+                if (delete) {
+                        kfree(l);
+                        le->link = NULL;
+                        n->link_cnt--;
+                }
+        } else {
+                /* Defuse pending tipc_node_link_up() */
+                tipc_link_fsm_evt(l, LINK_RESET_EVT);
         }
         tipc_node_unlock(n);
 
@@ -579,7 +592,7 @@ void tipc_node_check_dest(struct net *net, u32 onode,
         memcpy(&le->maddr, maddr, sizeof(*maddr));
 exit:
         tipc_node_unlock(n);
-        if (reset)
+        if (reset && !tipc_link_is_reset(l))
                 tipc_node_link_down(n, b->identity, false);
         tipc_node_put(n);
 }
@@ -686,10 +699,10 @@ static void tipc_node_fsm_evt(struct tipc_node *n, int evt)
                         break;
                 case SELF_ESTABL_CONTACT_EVT:
                 case PEER_LOST_CONTACT_EVT:
-                        break;
                 case NODE_SYNCH_END_EVT:
-                case NODE_SYNCH_BEGIN_EVT:
                 case NODE_FAILOVER_BEGIN_EVT:
+                        break;
+                case NODE_SYNCH_BEGIN_EVT:
                 case NODE_FAILOVER_END_EVT:
                 default:
                         goto illegal_evt;