Merge remote-tracking branch 'asoc/fix/rt5645' into asoc-fix-rt5645

1 files changed, 844 insertions, 135 deletions

diff --git a/net/tipc/node.c b/net/tipc/node.c
index 0b1d61a5f853..703875fd6cde 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -40,10 +40,42 @@
 #include "name_distr.h"
 #include "socket.h"
 #include "bcast.h"
+#include "discover.h"
 
-static void node_lost_contact(struct tipc_node *n_ptr);
+/* Node FSM states and events:
+ */
+enum {
+        SELF_DOWN_PEER_DOWN    = 0xdd,
+        SELF_UP_PEER_UP        = 0xaa,
+        SELF_DOWN_PEER_LEAVING = 0xd1,
+        SELF_UP_PEER_COMING    = 0xac,
+        SELF_COMING_PEER_UP    = 0xca,
+        SELF_LEAVING_PEER_DOWN = 0x1d,
+        NODE_FAILINGOVER       = 0xf0,
+        NODE_SYNCHING          = 0xcc
+};
+
+enum {
+        SELF_ESTABL_CONTACT_EVT = 0xece,
+        SELF_LOST_CONTACT_EVT   = 0x1ce,
+        PEER_ESTABL_CONTACT_EVT = 0x9ece,
+        PEER_LOST_CONTACT_EVT   = 0x91ce,
+        NODE_FAILOVER_BEGIN_EVT = 0xfbe,
+        NODE_FAILOVER_END_EVT   = 0xfee,
+        NODE_SYNCH_BEGIN_EVT    = 0xcbe,
+        NODE_SYNCH_END_EVT      = 0xcee
+};
+
+static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
+                                  struct sk_buff_head *xmitq,
+                                  struct tipc_media_addr **maddr);
+static void tipc_node_link_down(struct tipc_node *n, int bearer_id,
+                                bool delete);
+static void node_lost_contact(struct tipc_node *n, struct sk_buff_head *inputq);
 static void node_established_contact(struct tipc_node *n_ptr);
 static void tipc_node_delete(struct tipc_node *node);
+static void tipc_node_timeout(unsigned long data);
+static void tipc_node_fsm_evt(struct tipc_node *n, int evt);
 
 struct tipc_sock_conn {
         u32 port;
@@ -110,7 +142,7 @@ struct tipc_node *tipc_node_find(struct net *net, u32 addr)
         return NULL;
 }
 
-struct tipc_node *tipc_node_create(struct net *net, u32 addr)
+struct tipc_node *tipc_node_create(struct net *net, u32 addr, u16 capabilities)
 {
         struct tipc_net *tn = net_generic(net, tipc_net_id);
         struct tipc_node *n_ptr, *temp_node;
@@ -126,12 +158,14 @@ struct tipc_node *tipc_node_create(struct net *net, u32 addr)
         }
         n_ptr->addr = addr;
         n_ptr->net = net;
+        n_ptr->capabilities = capabilities;
         kref_init(&n_ptr->kref);
         spin_lock_init(&n_ptr->lock);
         INIT_HLIST_NODE(&n_ptr->hash);
         INIT_LIST_HEAD(&n_ptr->list);
         INIT_LIST_HEAD(&n_ptr->publ_list);
         INIT_LIST_HEAD(&n_ptr->conn_sks);
+        skb_queue_head_init(&n_ptr->bclink.namedq);
         __skb_queue_head_init(&n_ptr->bclink.deferdq);
         hlist_add_head_rcu(&n_ptr->hash, &tn->node_htable[tipc_hashfn(addr)]);
         list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
@@ -139,14 +173,32 @@ 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_LEAVING;
         n_ptr->signature = INVALID_NODE_SIG;
+        n_ptr->active_links[0] = INVALID_BEARER_ID;
+        n_ptr->active_links[1] = INVALID_BEARER_ID;
         tipc_node_get(n_ptr);
+        setup_timer(&n_ptr->timer, tipc_node_timeout, (unsigned long)n_ptr);
+        n_ptr->keepalive_intv = U32_MAX;
 exit:
         spin_unlock_bh(&tn->node_list_lock);
         return n_ptr;
 }
 
+static void tipc_node_calculate_timer(struct tipc_node *n, struct tipc_link *l)
+{
+        unsigned long tol = l->tolerance;
+        unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
+        unsigned long keepalive_intv = msecs_to_jiffies(intv);
+
+        /* Link with lowest tolerance determines timer interval */
+        if (keepalive_intv < n->keepalive_intv)
+                n->keepalive_intv = keepalive_intv;
+
+        /* Ensure link's abort limit corresponds to current interval */
+        l->abort_limit = l->tolerance / jiffies_to_msecs(n->keepalive_intv);
+}
+
 static void tipc_node_delete(struct tipc_node *node)
 {
         list_del_rcu(&node->list);
@@ -160,8 +212,11 @@ void tipc_node_stop(struct net *net)
         struct tipc_node *node, *t_node;
 
         spin_lock_bh(&tn->node_list_lock);
-        list_for_each_entry_safe(node, t_node, &tn->node_list, list)
+        list_for_each_entry_safe(node, t_node, &tn->node_list, list) {
+                if (del_timer(&node->timer))
+                        tipc_node_put(node);
                 tipc_node_put(node);
+        }
         spin_unlock_bh(&tn->node_list_lock);
 }
 
@@ -219,158 +274,551 @@ void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port)
         tipc_node_put(node);
 }
 
+/* tipc_node_timeout - handle expiration of node timer
+ */
+static void tipc_node_timeout(unsigned long data)
+{
+        struct tipc_node *n = (struct tipc_node *)data;
+        struct tipc_link_entry *le;
+        struct sk_buff_head xmitq;
+        int bearer_id;
+        int rc = 0;
+
+        __skb_queue_head_init(&xmitq);
+
+        for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
+                tipc_node_lock(n);
+                le = &n->links[bearer_id];
+                if (le->link) {
+                        /* Link tolerance may change asynchronously: */
+                        tipc_node_calculate_timer(n, le->link);
+                        rc = tipc_link_timeout(le->link, &xmitq);
+                }
+                tipc_node_unlock(n);
+                tipc_bearer_xmit(n->net, bearer_id, &xmitq, &le->maddr);
+                if (rc & TIPC_LINK_DOWN_EVT)
+                        tipc_node_link_down(n, bearer_id, false);
+        }
+        if (!mod_timer(&n->timer, jiffies + n->keepalive_intv))
+                tipc_node_get(n);
+        tipc_node_put(n);
+}
+
 /**
- * tipc_node_link_up - handle addition of link
- *
+ * __tipc_node_link_up - handle addition of link
+ * Node lock must be held by caller
  * Link becomes active (alone or shared) or standby, depending on its priority.
  */
-void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
+static void __tipc_node_link_up(struct tipc_node *n, int bearer_id,
+                                struct sk_buff_head *xmitq)
 {
-        struct tipc_link **active = &n_ptr->active_links[0];
+        int *slot0 = &n->active_links[0];
+        int *slot1 = &n->active_links[1];
+        struct tipc_link *ol = node_active_link(n, 0);
+        struct tipc_link *nl = n->links[bearer_id].link;
 
-        n_ptr->working_links++;
-        n_ptr->action_flags |= TIPC_NOTIFY_LINK_UP;
-        n_ptr->link_id = l_ptr->peer_bearer_id << 16 | l_ptr->bearer_id;
+        if (!nl || !tipc_link_is_up(nl))
+                return;
 
-        pr_debug("Established link <%s> on network plane %c\n",
-                 l_ptr->name, l_ptr->net_plane);
+        n->working_links++;
+        n->action_flags |= TIPC_NOTIFY_LINK_UP;
+        n->link_id = nl->peer_bearer_id << 16 | bearer_id;
 
-        if (!active[0]) {
-                active[0] = active[1] = l_ptr;
-                node_established_contact(n_ptr);
-                goto exit;
-        }
-        if (l_ptr->priority < active[0]->priority) {
-                pr_debug("New link <%s> becomes standby\n", l_ptr->name);
-                goto exit;
+        /* Leave room for tunnel header when returning 'mtu' to users: */
+        n->links[bearer_id].mtu = nl->mtu - INT_H_SIZE;
+
+        tipc_bearer_add_dest(n->net, bearer_id, n->addr);
+
+        pr_debug("Established link <%s> on network plane %c\n",
+                 nl->name, nl->net_plane);
+
+        /* First link? => give it both slots */
+        if (!ol) {
+                *slot0 = bearer_id;
+                *slot1 = bearer_id;
+                tipc_link_build_bcast_sync_msg(nl, xmitq);
+                node_established_contact(n);
+                return;
         }
-        tipc_link_dup_queue_xmit(active[0], l_ptr);
-        if (l_ptr->priority == active[0]->priority) {
-                active[0] = l_ptr;
-                goto exit;
+
+        /* Second link => redistribute slots */
+        if (nl->priority > ol->priority) {
+                pr_debug("Old link <%s> becomes standby\n", ol->name);
+                *slot0 = bearer_id;
+                *slot1 = bearer_id;
+        } else if (nl->priority == ol->priority) {
+                *slot0 = bearer_id;
+        } else {
+                pr_debug("New link <%s> is standby\n", nl->name);
         }
-        pr_debug("Old link <%s> becomes standby\n", active[0]->name);
-        if (active[1] != active[0])
-                pr_debug("Old link <%s> becomes standby\n", active[1]->name);
-        active[0] = active[1] = l_ptr;
-exit:
-        /* Leave room for changeover header when returning 'mtu' to users: */
-        n_ptr->act_mtus[0] = active[0]->mtu - INT_H_SIZE;
-        n_ptr->act_mtus[1] = active[1]->mtu - INT_H_SIZE;
+
+        /* Prepare synchronization with first link */
+        tipc_link_tnl_prepare(ol, nl, SYNCH_MSG, xmitq);
 }
 
 /**
- * node_select_active_links - select active link
+ * tipc_node_link_up - handle addition of link
+ *
+ * Link becomes active (alone or shared) or standby, depending on its priority.
  */
-static void node_select_active_links(struct tipc_node *n_ptr)
+static void tipc_node_link_up(struct tipc_node *n, int bearer_id,
+                              struct sk_buff_head *xmitq)
 {
-        struct tipc_link **active = &n_ptr->active_links[0];
-        u32 i;
-        u32 highest_prio = 0;
+        tipc_node_lock(n);
+        __tipc_node_link_up(n, bearer_id, xmitq);
+        tipc_node_unlock(n);
+}
 
-        active[0] = active[1] = NULL;
+/**
+ * __tipc_node_link_down - handle loss of link
+ */
+static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
+                                  struct sk_buff_head *xmitq,
+                                  struct tipc_media_addr **maddr)
+{
+        struct tipc_link_entry *le = &n->links[*bearer_id];
+        int *slot0 = &n->active_links[0];
+        int *slot1 = &n->active_links[1];
+        int i, highest = 0;
+        struct tipc_link *l, *_l, *tnl;
+
+        l = n->links[*bearer_id].link;
+        if (!l || tipc_link_is_reset(l))
+                return;
 
-        for (i = 0; i < MAX_BEARERS; i++) {
-                struct tipc_link *l_ptr = n_ptr->links[i];
+        n->working_links--;
+        n->action_flags |= TIPC_NOTIFY_LINK_DOWN;
+        n->link_id = l->peer_bearer_id << 16 | *bearer_id;
 
-                if (!l_ptr || !tipc_link_is_up(l_ptr) ||
-                    (l_ptr->priority < highest_prio))
-                        continue;
+        tipc_bearer_remove_dest(n->net, *bearer_id, n->addr);
 
-                if (l_ptr->priority > highest_prio) {
-                        highest_prio = l_ptr->priority;
-                        active[0] = active[1] = l_ptr;
-                } else {
-                        active[1] = l_ptr;
+        pr_debug("Lost link <%s> on network plane %c\n",
+                 l->name, l->net_plane);
+
+        /* Select new active link if any available */
+        *slot0 = INVALID_BEARER_ID;
+        *slot1 = INVALID_BEARER_ID;
+        for (i = 0; i < MAX_BEARERS; i++) {
+                _l = n->links[i].link;
+                if (!_l || !tipc_link_is_up(_l))
+                        continue;
+                if (_l == l)
+                        continue;
+                if (_l->priority < highest)
+                        continue;
+                if (_l->priority > highest) {
+                        highest = _l->priority;
+                        *slot0 = i;
+                        *slot1 = i;
+                        continue;
                 }
+                *slot1 = i;
+        }
+
+        if (!tipc_node_is_up(n)) {
+                tipc_link_reset(l);
+                node_lost_contact(n, &le->inputq);
+                return;
         }
+
+        /* There is still a working link => initiate failover */
+        tnl = node_active_link(n, 0);
+        tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
+        tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
+        n->sync_point = tnl->rcv_nxt + (U16_MAX / 2 - 1);
+        tipc_link_tnl_prepare(l, tnl, FAILOVER_MSG, xmitq);
+        tipc_link_reset(l);
+        tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
+        tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
+        *maddr = &n->links[tnl->bearer_id].maddr;
+        *bearer_id = tnl->bearer_id;
 }
 
-/**
- * tipc_node_link_down - handle loss of link
- */
-void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
+static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
 {
-        struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id);
-        struct tipc_link **active;
+        struct tipc_link_entry *le = &n->links[bearer_id];
+        struct tipc_media_addr *maddr;
+        struct sk_buff_head xmitq;
+
+        __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--;
+        }
+        tipc_node_unlock(n);
 
-        n_ptr->working_links--;
-        n_ptr->action_flags |= TIPC_NOTIFY_LINK_DOWN;
-        n_ptr->link_id = l_ptr->peer_bearer_id << 16 | l_ptr->bearer_id;
+        tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr);
+        tipc_sk_rcv(n->net, &le->inputq);
+}
 
-        if (!tipc_link_is_active(l_ptr)) {
-                pr_debug("Lost standby link <%s> on network plane %c\n",
-                         l_ptr->name, l_ptr->net_plane);
-                return;
-        }
-        pr_debug("Lost link <%s> on network plane %c\n",
-                 l_ptr->name, l_ptr->net_plane);
-
-        active = &n_ptr->active_links[0];
-        if (active[0] == l_ptr)
-                active[0] = active[1];
-        if (active[1] == l_ptr)
-                active[1] = active[0];
-        if (active[0] == l_ptr)
-                node_select_active_links(n_ptr);
-        if (tipc_node_is_up(n_ptr))
-                tipc_link_failover_send_queue(l_ptr);
-        else
-                node_lost_contact(n_ptr);
-
-        /* Leave room for changeover header when returning 'mtu' to users: */
-        if (active[0]) {
-                n_ptr->act_mtus[0] = active[0]->mtu - INT_H_SIZE;
-                n_ptr->act_mtus[1] = active[1]->mtu - INT_H_SIZE;
+bool tipc_node_is_up(struct tipc_node *n)
+{
+        return n->active_links[0] != INVALID_BEARER_ID;
+}
+
+void tipc_node_check_dest(struct net *net, u32 onode,
+                          struct tipc_bearer *b,
+                          u16 capabilities, u32 signature,
+                          struct tipc_media_addr *maddr,
+                          bool *respond, bool *dupl_addr)
+{
+        struct tipc_node *n;
+        struct tipc_link *l;
+        struct tipc_link_entry *le;
+        bool addr_match = false;
+        bool sign_match = false;
+        bool link_up = false;
+        bool accept_addr = false;
+        bool reset = true;
+
+        *dupl_addr = false;
+        *respond = false;
+
+        n = tipc_node_create(net, onode, capabilities);
+        if (!n)
                 return;
+
+        tipc_node_lock(n);
+
+        le = &n->links[b->identity];
+
+        /* Prepare to validate requesting node's signature and media address */
+        l = le->link;
+        link_up = l && tipc_link_is_up(l);
+        addr_match = l && !memcmp(&le->maddr, maddr, sizeof(*maddr));
+        sign_match = (signature == n->signature);
+
+        /* These three flags give us eight permutations: */
+
+        if (sign_match && addr_match && link_up) {
+                /* All is fine. Do nothing. */
+                reset = false;
+        } else if (sign_match && addr_match && !link_up) {
+                /* Respond. The link will come up in due time */
+                *respond = true;
+        } else if (sign_match && !addr_match && link_up) {
+                /* Peer has changed i/f address without rebooting.
+                 * If so, the link will reset soon, and the next
+                 * discovery will be accepted. So we can ignore it.
+                 * It may also be an cloned or malicious peer having
+                 * chosen the same node address and signature as an
+                 * existing one.
+                 * Ignore requests until the link goes down, if ever.
+                 */
+                *dupl_addr = true;
+        } else if (sign_match && !addr_match && !link_up) {
+                /* Peer link has changed i/f address without rebooting.
+                 * It may also be a cloned or malicious peer; we can't
+                 * distinguish between the two.
+                 * The signature is correct, so we must accept.
+                 */
+                accept_addr = true;
+                *respond = true;
+        } else if (!sign_match && addr_match && link_up) {
+                /* Peer node rebooted. Two possibilities:
+                 *  - Delayed re-discovery; this link endpoint has already
+                 *    reset and re-established contact with the peer, before
+                 *    receiving a discovery message from that node.
+                 *    (The peer happened to receive one from this node first).
+                 *  - The peer came back so fast that our side has not
+                 *    discovered it yet. Probing from this side will soon
+                 *    reset the link, since there can be no working link
+                 *    endpoint at the peer end, and the link will re-establish.
+                 *  Accept the signature, since it comes from a known peer.
+                 */
+                n->signature = signature;
+        } else if (!sign_match && addr_match && !link_up) {
+                /*  The peer node has rebooted.
+                 *  Accept signature, since it is a known peer.
+                 */
+                n->signature = signature;
+                *respond = true;
+        } else if (!sign_match && !addr_match && link_up) {
+                /* Peer rebooted with new address, or a new/duplicate peer.
+                 * Ignore until the link goes down, if ever.
+                 */
+                *dupl_addr = true;
+        } else if (!sign_match && !addr_match && !link_up) {
+                /* Peer rebooted with new address, or it is a new peer.
+                 * Accept signature and address.
+                 */
+                n->signature = signature;
+                accept_addr = true;
+                *respond = true;
         }
-        /* Loopback link went down? No fragmentation needed from now on. */
-        if (n_ptr->addr == tn->own_addr) {
-                n_ptr->act_mtus[0] = MAX_MSG_SIZE;
-                n_ptr->act_mtus[1] = MAX_MSG_SIZE;
+
+        if (!accept_addr)
+                goto exit;
+
+        /* Now create new link if not already existing */
+        if (!l) {
+                if (n->link_cnt == 2) {
+                        pr_warn("Cannot establish 3rd link to %x\n", n->addr);
+                        goto exit;
+                }
+                if (!tipc_link_create(n, b, mod(tipc_net(net)->random),
+                                      tipc_own_addr(net), onode, &le->maddr,
+                                      &le->inputq, &n->bclink.namedq, &l)) {
+                        *respond = false;
+                        goto exit;
+                }
+                tipc_link_reset(l);
+                if (n->state == NODE_FAILINGOVER)
+                        tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
+                le->link = l;
+                n->link_cnt++;
+                tipc_node_calculate_timer(n, l);
+                if (n->link_cnt == 1)
+                        if (!mod_timer(&n->timer, jiffies + n->keepalive_intv))
+                                tipc_node_get(n);
         }
+        memcpy(&le->maddr, maddr, sizeof(*maddr));
+exit:
+        tipc_node_unlock(n);
+        if (reset)
+                tipc_node_link_down(n, b->identity, false);
+        tipc_node_put(n);
 }
 
-int tipc_node_active_links(struct tipc_node *n_ptr)
+void tipc_node_delete_links(struct net *net, int bearer_id)
 {
-        return n_ptr->active_links[0] != NULL;
+        struct tipc_net *tn = net_generic(net, tipc_net_id);
+        struct tipc_node *n;
+
+        rcu_read_lock();
+        list_for_each_entry_rcu(n, &tn->node_list, list) {
+                tipc_node_link_down(n, bearer_id, true);
+        }
+        rcu_read_unlock();
 }
 
-int tipc_node_is_up(struct tipc_node *n_ptr)
+static void tipc_node_reset_links(struct tipc_node *n)
 {
-        return tipc_node_active_links(n_ptr);
+        char addr_string[16];
+        int i;
+
+        pr_warn("Resetting all links to %s\n",
+                tipc_addr_string_fill(addr_string, n->addr));
+
+        for (i = 0; i < MAX_BEARERS; i++) {
+                tipc_node_link_down(n, i, false);
+        }
 }
 
-void tipc_node_attach_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
+ */
+static void tipc_node_fsm_evt(struct tipc_node *n, int evt)
 {
-        n_ptr->links[l_ptr->bearer_id] = l_ptr;
-        n_ptr->link_cnt++;
+        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;
+                case NODE_SYNCH_END_EVT:
+                case NODE_SYNCH_BEGIN_EVT:
+                case NODE_FAILOVER_BEGIN_EVT:
+                case NODE_FAILOVER_END_EVT:
+                default:
+                        goto illegal_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 NODE_SYNCH_BEGIN_EVT:
+                        state = NODE_SYNCHING;
+                        break;
+                case NODE_FAILOVER_BEGIN_EVT:
+                        state = NODE_FAILINGOVER;
+                        break;
+                case SELF_ESTABL_CONTACT_EVT:
+                case PEER_ESTABL_CONTACT_EVT:
+                case NODE_SYNCH_END_EVT:
+                case NODE_FAILOVER_END_EVT:
+                        break;
+                default:
+                        goto illegal_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;
+                case NODE_SYNCH_END_EVT:
+                case NODE_SYNCH_BEGIN_EVT:
+                case NODE_FAILOVER_BEGIN_EVT:
+                case NODE_FAILOVER_END_EVT:
+                default:
+                        goto illegal_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;
+                case NODE_SYNCH_END_EVT:
+                case NODE_SYNCH_BEGIN_EVT:
+                case NODE_FAILOVER_BEGIN_EVT:
+                case NODE_FAILOVER_END_EVT:
+                default:
+                        goto illegal_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;
+                case NODE_SYNCH_END_EVT:
+                case NODE_SYNCH_BEGIN_EVT:
+                case NODE_FAILOVER_BEGIN_EVT:
+                case NODE_FAILOVER_END_EVT:
+                default:
+                        goto illegal_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;
+                case NODE_SYNCH_END_EVT:
+                case NODE_SYNCH_BEGIN_EVT:
+                case NODE_FAILOVER_BEGIN_EVT:
+                case NODE_FAILOVER_END_EVT:
+                default:
+                        goto illegal_evt;
+                }
+                break;
+        case NODE_FAILINGOVER:
+                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 NODE_FAILOVER_END_EVT:
+                        state = SELF_UP_PEER_UP;
+                        break;
+                case NODE_FAILOVER_BEGIN_EVT:
+                case SELF_ESTABL_CONTACT_EVT:
+                case PEER_ESTABL_CONTACT_EVT:
+                        break;
+                case NODE_SYNCH_BEGIN_EVT:
+                case NODE_SYNCH_END_EVT:
+                default:
+                        goto illegal_evt;
+                }
+                break;
+        case NODE_SYNCHING:
+                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 NODE_SYNCH_END_EVT:
+                        state = SELF_UP_PEER_UP;
+                        break;
+                case NODE_FAILOVER_BEGIN_EVT:
+                        state = NODE_FAILINGOVER;
+                        break;
+                case NODE_SYNCH_BEGIN_EVT:
+                case SELF_ESTABL_CONTACT_EVT:
+                case PEER_ESTABL_CONTACT_EVT:
+                        break;
+                case NODE_FAILOVER_END_EVT:
+                default:
+                        goto illegal_evt;
+                }
+                break;
+        default:
+                pr_err("Unknown node fsm state %x\n", state);
+                break;
+        }
+        n->state = state;
+        return;
+
+illegal_evt:
+        pr_err("Illegal node fsm evt %x in state %x\n", evt, state);
 }
 
-void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
+bool tipc_node_filter_pkt(struct tipc_node *n, struct tipc_msg *hdr)
 {
-        int i;
+        int state = n->state;
 
-        for (i = 0; i < MAX_BEARERS; i++) {
-                if (l_ptr != n_ptr->links[i])
-                        continue;
-                n_ptr->links[i] = NULL;
-                n_ptr->link_cnt--;
+        if (likely(state == SELF_UP_PEER_UP))
+                return true;
+
+        if (state == SELF_LEAVING_PEER_DOWN)
+                return false;
+
+        if (state == SELF_DOWN_PEER_LEAVING) {
+                if (msg_peer_node_is_up(hdr))
+                        return false;
         }
+
+        return true;
 }
 
 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);
         tipc_bclink_add_node(n_ptr->net, n_ptr->addr);
 }
 
-static void node_lost_contact(struct tipc_node *n_ptr)
+static void node_lost_contact(struct tipc_node *n_ptr,
+                              struct sk_buff_head *inputq)
 {
         char addr_string[16];
         struct tipc_sock_conn *conn, *safe;
+        struct tipc_link *l;
         struct list_head *conns = &n_ptr->conn_sks;
         struct sk_buff *skb;
         struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id);
@@ -396,21 +844,13 @@ static void node_lost_contact(struct tipc_node *n_ptr)
 
         /* Abort any ongoing link failover */
         for (i = 0; i < MAX_BEARERS; i++) {
-                struct tipc_link *l_ptr = n_ptr->links[i];
-                if (!l_ptr)
-                        continue;
-                l_ptr->flags &= ~LINK_FAILINGOVER;
-                l_ptr->failover_checkpt = 0;
-                l_ptr->failover_pkts = 0;
-                kfree_skb(l_ptr->failover_skb);
-                l_ptr->failover_skb = NULL;
-                tipc_link_reset_fragments(l_ptr);
+                l = n_ptr->links[i].link;
+                if (l)
+                        tipc_link_fsm_evt(l, LINK_FAILOVER_END_EVT);
         }
 
-        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;
@@ -421,10 +861,8 @@ static void node_lost_contact(struct tipc_node *n_ptr)
                                       SHORT_H_SIZE, 0, tn->own_addr,
                                       conn->peer_node, conn->port,
                                       conn->peer_port, TIPC_ERR_NO_NODE);
-                if (likely(skb)) {
-                        skb_queue_tail(n_ptr->inputq, skb);
-                        n_ptr->action_flags |= TIPC_MSG_EVT;
-                }
+                if (likely(skb))
+                        skb_queue_tail(inputq, skb);
                 list_del(&conn->list);
                 kfree(conn);
         }
@@ -453,7 +891,7 @@ int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr,
                 goto exit;
 
         tipc_node_lock(node);
-        link = node->links[bearer_id];
+        link = node->links[bearer_id].link;
         if (link) {
                 strncpy(linkname, link->name, len);
                 err = 0;
@@ -471,27 +909,20 @@ void tipc_node_unlock(struct tipc_node *node)
         u32 flags = node->action_flags;
         u32 link_id = 0;
         struct list_head *publ_list;
-        struct sk_buff_head *inputq = node->inputq;
-        struct sk_buff_head *namedq;
 
-        if (likely(!flags || (flags == TIPC_MSG_EVT))) {
-                node->action_flags = 0;
+        if (likely(!flags)) {
                 spin_unlock_bh(&node->lock);
-                if (flags == TIPC_MSG_EVT)
-                        tipc_sk_rcv(net, inputq);
                 return;
         }
 
         addr = node->addr;
         link_id = node->link_id;
-        namedq = node->namedq;
         publ_list = &node->publ_list;
 
-        node->action_flags &= ~(TIPC_MSG_EVT |
-                                TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP |
+        node->action_flags &= ~(TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP |
                                 TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP |
                                 TIPC_WAKEUP_BCAST_USERS | TIPC_BCAST_MSG_EVT |
-                                TIPC_NAMED_MSG_EVT | TIPC_BCAST_RESET);
+                                TIPC_BCAST_RESET);
 
         spin_unlock_bh(&node->lock);
 
@@ -512,17 +943,11 @@ void tipc_node_unlock(struct tipc_node *node)
                 tipc_nametbl_withdraw(net, TIPC_LINK_STATE, addr,
                                       link_id, addr);
 
-        if (flags & TIPC_MSG_EVT)
-                tipc_sk_rcv(net, inputq);
-
-        if (flags & TIPC_NAMED_MSG_EVT)
-                tipc_named_rcv(net, namedq);
-
         if (flags & TIPC_BCAST_MSG_EVT)
                 tipc_bclink_input(net);
 
         if (flags & TIPC_BCAST_RESET)
-                tipc_link_reset_all(node);
+                tipc_node_reset_links(node);
 }
 
 /* Caller should hold node lock for the passed node */
@@ -559,6 +984,290 @@ msg_full:
         return -EMSGSIZE;
 }
 
+static struct tipc_link *tipc_node_select_link(struct tipc_node *n, int sel,
+                                               int *bearer_id,
+                                               struct tipc_media_addr **maddr)
+{
+        int id = n->active_links[sel & 1];
+
+        if (unlikely(id < 0))
+                return NULL;
+
+        *bearer_id = id;
+        *maddr = &n->links[id].maddr;
+        return n->links[id].link;
+}
+
+/**
+ * tipc_node_xmit() is the general link level function for message sending
+ * @net: the applicable net namespace
+ * @list: chain of buffers containing message
+ * @dnode: address of destination node
+ * @selector: a number used for deterministic link selection
+ * Consumes the buffer chain, except when returning -ELINKCONG
+ * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
+ */
+int tipc_node_xmit(struct net *net, struct sk_buff_head *list,
+                   u32 dnode, int selector)
+{
+        struct tipc_link *l = NULL;
+        struct tipc_node *n;
+        struct sk_buff_head xmitq;
+        struct tipc_media_addr *maddr;
+        int bearer_id;
+        int rc = -EHOSTUNREACH;
+
+        __skb_queue_head_init(&xmitq);
+        n = tipc_node_find(net, dnode);
+        if (likely(n)) {
+                tipc_node_lock(n);
+                l = tipc_node_select_link(n, selector, &bearer_id, &maddr);
+                if (likely(l))
+                        rc = tipc_link_xmit(l, list, &xmitq);
+                tipc_node_unlock(n);
+                if (unlikely(rc == -ENOBUFS))
+                        tipc_node_link_down(n, bearer_id, false);
+                tipc_node_put(n);
+        }
+        if (likely(!rc)) {
+                tipc_bearer_xmit(net, bearer_id, &xmitq, maddr);
+                return 0;
+        }
+        if (likely(in_own_node(net, dnode))) {
+                tipc_sk_rcv(net, list);
+                return 0;
+        }
+        return rc;
+}
+
+/* tipc_node_xmit_skb(): send single buffer to destination
+ * Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
+ * messages, which will not be rejected
+ * The only exception is datagram messages rerouted after secondary
+ * lookup, which are rare and safe to dispose of anyway.
+ * TODO: Return real return value, and let callers use
+ * tipc_wait_for_sendpkt() where applicable
+ */
+int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
+                       u32 selector)
+{
+        struct sk_buff_head head;
+        int rc;
+
+        skb_queue_head_init(&head);
+        __skb_queue_tail(&head, skb);
+        rc = tipc_node_xmit(net, &head, dnode, selector);
+        if (rc == -ELINKCONG)
+                kfree_skb(skb);
+        return 0;
+}
+
+/**
+ * tipc_node_check_state - check and if necessary update node state
+ * @skb: TIPC packet
+ * @bearer_id: identity of bearer delivering the packet
+ * Returns true if state is ok, otherwise consumes buffer and returns false
+ */
+static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
+                                  int bearer_id, struct sk_buff_head *xmitq)
+{
+        struct tipc_msg *hdr = buf_msg(skb);
+        int usr = msg_user(hdr);
+        int mtyp = msg_type(hdr);
+        u16 oseqno = msg_seqno(hdr);
+        u16 iseqno = msg_seqno(msg_get_wrapped(hdr));
+        u16 exp_pkts = msg_msgcnt(hdr);
+        u16 rcv_nxt, syncpt, dlv_nxt;
+        int state = n->state;
+        struct tipc_link *l, *tnl, *pl = NULL;
+        struct tipc_media_addr *maddr;
+        int i, pb_id;
+
+        l = n->links[bearer_id].link;
+        if (!l)
+                return false;
+        rcv_nxt = l->rcv_nxt;
+
+
+        if (likely((state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL)))
+                return true;
+
+        /* Find parallel link, if any */
+        for (i = 0; i < MAX_BEARERS; i++) {
+                if ((i != bearer_id) && n->links[i].link) {
+                        pl = n->links[i].link;
+                        break;
+                }
+        }
+
+        /* Update node accesibility if applicable */
+        if (state == SELF_UP_PEER_COMING) {
+                if (!tipc_link_is_up(l))
+                        return true;
+                if (!msg_peer_link_is_up(hdr))
+                        return true;
+                tipc_node_fsm_evt(n, PEER_ESTABL_CONTACT_EVT);
+        }
+
+        if (state == SELF_DOWN_PEER_LEAVING) {
+                if (msg_peer_node_is_up(hdr))
+                        return false;
+                tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
+        }
+
+        /* Ignore duplicate packets */
+        if (less(oseqno, rcv_nxt))
+                return true;
+
+        /* Initiate or update failover mode if applicable */
+        if ((usr == TUNNEL_PROTOCOL) && (mtyp == FAILOVER_MSG)) {
+                syncpt = oseqno + exp_pkts - 1;
+                if (pl && tipc_link_is_up(pl)) {
+                        pb_id = pl->bearer_id;
+                        __tipc_node_link_down(n, &pb_id, xmitq, &maddr);
+                        tipc_skb_queue_splice_tail_init(pl->inputq, l->inputq);
+                }
+                /* If pkts arrive out of order, use lowest calculated syncpt */
+                if (less(syncpt, n->sync_point))
+                        n->sync_point = syncpt;
+        }
+
+        /* Open parallel link when tunnel link reaches synch point */
+        if ((n->state == NODE_FAILINGOVER) && tipc_link_is_up(l)) {
+                if (!more(rcv_nxt, n->sync_point))
+                        return true;
+                tipc_node_fsm_evt(n, NODE_FAILOVER_END_EVT);
+                if (pl)
+                        tipc_link_fsm_evt(pl, LINK_FAILOVER_END_EVT);
+                return true;
+        }
+
+        /* No synching needed if only one link */
+        if (!pl || !tipc_link_is_up(pl))
+                return true;
+
+        /* Initiate or update synch mode if applicable */
+        if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG)) {
+                syncpt = iseqno + exp_pkts - 1;
+                if (!tipc_link_is_up(l)) {
+                        tipc_link_fsm_evt(l, LINK_ESTABLISH_EVT);
+                        __tipc_node_link_up(n, bearer_id, xmitq);
+                }
+                if (n->state == SELF_UP_PEER_UP) {
+                        n->sync_point = syncpt;
+                        tipc_link_fsm_evt(l, LINK_SYNCH_BEGIN_EVT);
+                        tipc_node_fsm_evt(n, NODE_SYNCH_BEGIN_EVT);
+                }
+                if (less(syncpt, n->sync_point))
+                        n->sync_point = syncpt;
+        }
+
+        /* Open tunnel link when parallel link reaches synch point */
+        if ((n->state == NODE_SYNCHING) && tipc_link_is_synching(l)) {
+                if (tipc_link_is_synching(l)) {
+                        tnl = l;
+                } else {
+                        tnl = pl;
+                        pl = l;
+                }
+                dlv_nxt = pl->rcv_nxt - mod(skb_queue_len(pl->inputq));
+                if (more(dlv_nxt, n->sync_point)) {
+                        tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
+                        tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
+                        return true;
+                }
+                if (l == pl)
+                        return true;
+                if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG))
+                        return true;
+                if (usr == LINK_PROTOCOL)
+                        return true;
+                return false;
+        }
+        return true;
+}
+
+/**
+ * tipc_rcv - process TIPC packets/messages arriving from off-node
+ * @net: the applicable net namespace
+ * @skb: TIPC packet
+ * @bearer: pointer to bearer message arrived on
+ *
+ * Invoked with no locks held. Bearer pointer must point to a valid bearer
+ * structure (i.e. cannot be NULL), but bearer can be inactive.
+ */
+void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
+{
+        struct sk_buff_head xmitq;
+        struct tipc_node *n;
+        struct tipc_msg *hdr = buf_msg(skb);
+        int usr = msg_user(hdr);
+        int bearer_id = b->identity;
+        struct tipc_link_entry *le;
+        int rc = 0;
+
+        __skb_queue_head_init(&xmitq);
+
+        /* Ensure message is well-formed */
+        if (unlikely(!tipc_msg_validate(skb)))
+                goto discard;
+
+        /* Handle arrival of a non-unicast link packet */
+        if (unlikely(msg_non_seq(hdr))) {
+                if (usr ==  LINK_CONFIG)
+                        tipc_disc_rcv(net, skb, b);
+                else
+                        tipc_bclink_rcv(net, skb);
+                return;
+        }
+
+        /* Locate neighboring node that sent packet */
+        n = tipc_node_find(net, msg_prevnode(hdr));
+        if (unlikely(!n))
+                goto discard;
+        le = &n->links[bearer_id];
+
+        tipc_node_lock(n);
+
+        /* Is reception permitted at the moment ? */
+        if (!tipc_node_filter_pkt(n, hdr))
+                goto unlock;
+
+        if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
+                tipc_bclink_sync_state(n, hdr);
+
+        /* Release acked broadcast packets */
+        if (unlikely(n->bclink.acked != msg_bcast_ack(hdr)))
+                tipc_bclink_acknowledge(n, msg_bcast_ack(hdr));
+
+        /* Check and if necessary update node state */
+        if (likely(tipc_node_check_state(n, skb, bearer_id, &xmitq))) {
+                rc = tipc_link_rcv(le->link, skb, &xmitq);
+                skb = NULL;
+        }
+unlock:
+        tipc_node_unlock(n);
+
+        if (unlikely(rc & TIPC_LINK_UP_EVT))
+                tipc_node_link_up(n, bearer_id, &xmitq);
+
+        if (unlikely(rc & TIPC_LINK_DOWN_EVT))
+                tipc_node_link_down(n, bearer_id, false);
+
+        if (unlikely(!skb_queue_empty(&n->bclink.namedq)))
+                tipc_named_rcv(net, &n->bclink.namedq);
+
+        if (!skb_queue_empty(&le->inputq))
+                tipc_sk_rcv(net, &le->inputq);
+
+        if (!skb_queue_empty(&xmitq))
+                tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
+
+        tipc_node_put(n);
+discard:
+        kfree_skb(skb);
+}
+
 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
 {
         int err;