Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

Pull networking updates from David Miller:

 1) Add BQL support to via-rhine, from Tino Reichardt.

 2) Integrate SWITCHDEV layer support into the DSA layer, so DSA drivers
    can support hw switch offloading.  From Floria Fainelli.

 3) Allow 'ip address' commands to initiate multicast group join/leave,
    from Madhu Challa.

 4) Many ipv4 FIB lookup optimizations from Alexander Duyck.

 5) Support EBPF in cls_bpf classifier and act_bpf action, from Daniel
    Borkmann.

 6) Remove the ugly compat support in ARP for ugly layers like ax25,
    rose, etc.  And use this to clean up the neigh layer, then use it to
    implement MPLS support.  All from Eric Biederman.

 7) Support L3 forwarding offloading in switches, from Scott Feldman.

 8) Collapse the LOCAL and MAIN ipv4 FIB tables when possible, to speed
    up route lookups even further.  From Alexander Duyck.

 9) Many improvements and bug fixes to the rhashtable implementation,
    from Herbert Xu and Thomas Graf.  In particular, in the case where
    an rhashtable user bulk adds a large number of items into an empty
    table, we expand the table much more sanely.

10) Don't make the tcp_metrics hash table per-namespace, from Eric
    Biederman.

11) Extend EBPF to access SKB fields, from Alexei Starovoitov.

12) Split out new connection request sockets so that they can be
    established in the main hash table.  Much less false sharing since
    hash lookups go direct to the request sockets instead of having to
    go first to the listener then to the request socks hashed
    underneath.  From Eric Dumazet.

13) Add async I/O support for crytpo AF_ALG sockets, from Tadeusz Struk.

14) Support stable privacy address generation for RFC7217 in IPV6.  From
    Hannes Frederic Sowa.

15) Hash network namespace into IP frag IDs, also from Hannes Frederic
    Sowa.

16) Convert PTP get/set methods to use 64-bit time, from Richard
    Cochran.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1816 commits)
  fm10k: Bump driver version to 0.15.2
  fm10k: corrected VF multicast update
  fm10k: mbx_update_max_size does not drop all oversized messages
  fm10k: reset head instead of calling update_max_size
  fm10k: renamed mbx_tx_dropped to mbx_tx_oversized
  fm10k: update xcast mode before synchronizing multicast addresses
  fm10k: start service timer on probe
  fm10k: fix function header comment
  fm10k: comment next_vf_mbx flow
  fm10k: don't handle mailbox events in iov_event path and always process mailbox
  fm10k: use separate workqueue for fm10k driver
  fm10k: Set PF queues to unlimited bandwidth during virtualization
  fm10k: expose tx_timeout_count as an ethtool stat
  fm10k: only increment tx_timeout_count in Tx hang path
  fm10k: remove extraneous "Reset interface" message
  fm10k: separate PF only stats so that VF does not display them
  fm10k: use hw->mac.max_queues for stats
  fm10k: only show actual queues, not the maximum in hardware
  fm10k: allow creation of VLAN on default vid
  fm10k: fix unused warnings
  ...

1 files changed, 352 insertions, 510 deletions

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 14f09b3cb87c..a6b30df6ec02 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1,7 +1,7 @@
 /*
  * net/tipc/link.c: TIPC link code
  *
- * Copyright (c) 1996-2007, 2012-2014, Ericsson AB
+ * Copyright (c) 1996-2007, 2012-2015, Ericsson AB
  * Copyright (c) 2004-2007, 2010-2013, Wind River Systems
  * All rights reserved.
  *
@@ -35,6 +35,7 @@
  */
 
 #include "core.h"
+#include "subscr.h"
 #include "link.h"
 #include "bcast.h"
 #include "socket.h"
@@ -88,24 +89,14 @@ static const struct nla_policy tipc_nl_prop_policy[TIPC_NLA_PROP_MAX + 1] = {
 #define  TIMEOUT_EVT     560817u	/* link timer expired */
 
 /*
- * The following two 'message types' is really just implementation
- * data conveniently stored in the message header.
- * They must not be considered part of the protocol
+ * State value stored in 'failover_pkts'
  */
-#define OPEN_MSG   0
-#define CLOSED_MSG 1
-
-/*
- * State value stored in 'exp_msg_count'
- */
-#define START_CHANGEOVER 100000u
+#define FIRST_FAILOVER 0xffffu
 
 static void link_handle_out_of_seq_msg(struct tipc_link *link,
 				       struct sk_buff *skb);
 static void tipc_link_proto_rcv(struct tipc_link *link,
 				struct sk_buff *skb);
-static int  tipc_link_tunnel_rcv(struct tipc_node *node,
-				 struct sk_buff **skb);
 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tol);
 static void link_state_event(struct tipc_link *l_ptr, u32 event);
 static void link_reset_statistics(struct tipc_link *l_ptr);
@@ -114,7 +105,7 @@ static void tipc_link_sync_xmit(struct tipc_link *l);
 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf);
 static void tipc_link_input(struct tipc_link *l, struct sk_buff *skb);
 static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb);
-
+static bool tipc_link_failover_rcv(struct tipc_link *l, struct sk_buff **skb);
 /*
  *  Simple link routines
  */
@@ -138,32 +129,11 @@ static void tipc_link_put(struct tipc_link *l_ptr)
 	kref_put(&l_ptr->ref, tipc_link_release);
 }
 
-static void link_init_max_pkt(struct tipc_link *l_ptr)
+static struct tipc_link *tipc_parallel_link(struct tipc_link *l)
 {
-	struct tipc_node *node = l_ptr->owner;
-	struct tipc_net *tn = net_generic(node->net, tipc_net_id);
-	struct tipc_bearer *b_ptr;
-	u32 max_pkt;
-
-	rcu_read_lock();
-	b_ptr = rcu_dereference_rtnl(tn->bearer_list[l_ptr->bearer_id]);
-	if (!b_ptr) {
-		rcu_read_unlock();
-		return;
-	}
-	max_pkt = (b_ptr->mtu & ~3);
-	rcu_read_unlock();
-
-	if (max_pkt > MAX_MSG_SIZE)
-		max_pkt = MAX_MSG_SIZE;
-
-	l_ptr->max_pkt_target = max_pkt;
-	if (l_ptr->max_pkt_target < MAX_PKT_DEFAULT)
-		l_ptr->max_pkt = l_ptr->max_pkt_target;
-	else
-		l_ptr->max_pkt = MAX_PKT_DEFAULT;
-
-	l_ptr->max_pkt_probes = 0;
+	if (l->owner->active_links[0] != l)
+		return l->owner->active_links[0];
+	return l->owner->active_links[1];
 }
 
 /*
@@ -194,10 +164,10 @@ static void link_timeout(unsigned long data)
 	tipc_node_lock(l_ptr->owner);
 
 	/* update counters used in statistical profiling of send traffic */
-	l_ptr->stats.accu_queue_sz += skb_queue_len(&l_ptr->outqueue);
+	l_ptr->stats.accu_queue_sz += skb_queue_len(&l_ptr->transmq);
 	l_ptr->stats.queue_sz_counts++;
 
-	skb = skb_peek(&l_ptr->outqueue);
+	skb = skb_peek(&l_ptr->transmq);
 	if (skb) {
 		struct tipc_msg *msg = buf_msg(skb);
 		u32 length = msg_size(msg);
@@ -229,7 +199,7 @@ static void link_timeout(unsigned long data)
 	/* do all other link processing performed on a periodic basis */
 	link_state_event(l_ptr, TIMEOUT_EVT);
 
-	if (l_ptr->next_out)
+	if (skb_queue_len(&l_ptr->backlogq))
 		tipc_link_push_packets(l_ptr);
 
 	tipc_node_unlock(l_ptr->owner);
@@ -305,16 +275,15 @@ struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
 	msg_set_session(msg, (tn->random & 0xffff));
 	msg_set_bearer_id(msg, b_ptr->identity);
 	strcpy((char *)msg_data(msg), if_name);
-
+	l_ptr->net_plane = b_ptr->net_plane;
+	l_ptr->advertised_mtu = b_ptr->mtu;
+	l_ptr->mtu = l_ptr->advertised_mtu;
 	l_ptr->priority = b_ptr->priority;
 	tipc_link_set_queue_limits(l_ptr, b_ptr->window);
-
-	l_ptr->net_plane = b_ptr->net_plane;
-	link_init_max_pkt(l_ptr);
-
 	l_ptr->next_out_no = 1;
-	__skb_queue_head_init(&l_ptr->outqueue);
-	__skb_queue_head_init(&l_ptr->deferred_queue);
+	__skb_queue_head_init(&l_ptr->transmq);
+	__skb_queue_head_init(&l_ptr->backlogq);
+	__skb_queue_head_init(&l_ptr->deferdq);
 	skb_queue_head_init(&l_ptr->wakeupq);
 	skb_queue_head_init(&l_ptr->inputq);
 	skb_queue_head_init(&l_ptr->namedq);
@@ -327,15 +296,19 @@ struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
 }
 
 /**
- * link_delete - Conditional deletion of link.
- *               If timer still running, real delete is done when it expires
- * @link: link to be deleted
+ * tipc_link_delete - Delete a link
+ * @l: link to be deleted
  */
-void tipc_link_delete(struct tipc_link *link)
+void tipc_link_delete(struct tipc_link *l)
 {
-	tipc_link_reset_fragments(link);
-	tipc_node_detach_link(link->owner, link);
-	tipc_link_put(link);
+	tipc_link_reset(l);
+	if (del_timer(&l->timer))
+		tipc_link_put(l);
+	l->flags |= LINK_STOPPED;
+	/* Delete link now, or when timer is finished: */
+	tipc_link_reset_fragments(l);
+	tipc_node_detach_link(l->owner, l);
+	tipc_link_put(l);
 }
 
 void tipc_link_delete_list(struct net *net, unsigned int bearer_id,
@@ -349,16 +322,7 @@ void tipc_link_delete_list(struct net *net, unsigned int bearer_id,
 	list_for_each_entry_rcu(node, &tn->node_list, list) {
 		tipc_node_lock(node);
 		link = node->links[bearer_id];
-		if (!link) {
-			tipc_node_unlock(node);
-			continue;
-		}
-		tipc_link_reset(link);
-		if (del_timer(&link->timer))
-			tipc_link_put(link);
-		link->flags |= LINK_STOPPED;
-		/* Delete link now, or when failover is finished: */
-		if (shutting_down || !tipc_node_is_up(node))
+		if (link)
 			tipc_link_delete(link);
 		tipc_node_unlock(node);
 	}
@@ -366,28 +330,43 @@ void tipc_link_delete_list(struct net *net, unsigned int bearer_id,
 }
 
 /**
- * link_schedule_user - schedule user for wakeup after congestion
+ * link_schedule_user - schedule a message sender for wakeup after congestion
  * @link: congested link
- * @oport: sending port
- * @chain_sz: size of buffer chain that was attempted sent
- * @imp: importance of message attempted sent
+ * @list: message that was attempted sent
  * Create pseudo msg to send back to user when congestion abates
+ * Only consumes message if there is an error
  */
-static bool link_schedule_user(struct tipc_link *link, u32 oport,
-			       uint chain_sz, uint imp)
+static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
 {
-	struct sk_buff *buf;
+	struct tipc_msg *msg = buf_msg(skb_peek(list));
+	int imp = msg_importance(msg);
+	u32 oport = msg_origport(msg);
+	u32 addr = link_own_addr(link);
+	struct sk_buff *skb;
 
-	buf = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
-			      link_own_addr(link), link_own_addr(link),
-			      oport, 0, 0);
-	if (!buf)
-		return false;
-	TIPC_SKB_CB(buf)->chain_sz = chain_sz;
-	TIPC_SKB_CB(buf)->chain_imp = imp;
-	skb_queue_tail(&link->wakeupq, buf);
+	/* This really cannot happen...  */
+	if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
+		pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
+		tipc_link_reset(link);
+		goto err;
+	}
+	/* Non-blocking sender: */
+	if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending)
+		return -ELINKCONG;
+
+	/* Create and schedule wakeup pseudo message */
+	skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
+			      addr, addr, oport, 0, 0);
+	if (!skb)
+		goto err;
+	TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list);
+	TIPC_SKB_CB(skb)->chain_imp = imp;
+	skb_queue_tail(&link->wakeupq, skb);
 	link->stats.link_congs++;
-	return true;
+	return -ELINKCONG;
+err:
+	__skb_queue_purge(list);
+	return -ENOBUFS;
 }
 
 /**
@@ -396,19 +375,22 @@ static bool link_schedule_user(struct tipc_link *link, u32 oport,
  * Move a number of waiting users, as permitted by available space in
  * the send queue, from link wait queue to node wait queue for wakeup
  */
-void link_prepare_wakeup(struct tipc_link *link)
+void link_prepare_wakeup(struct tipc_link *l)
 {
-	uint pend_qsz = skb_queue_len(&link->outqueue);
+	int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,};
+	int imp, lim;
 	struct sk_buff *skb, *tmp;
 
-	skb_queue_walk_safe(&link->wakeupq, skb, tmp) {
-		if (pend_qsz >= link->queue_limit[TIPC_SKB_CB(skb)->chain_imp])
+	skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
+		imp = TIPC_SKB_CB(skb)->chain_imp;
+		lim = l->window + l->backlog[imp].limit;
+		pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
+		if ((pnd[imp] + l->backlog[imp].len) >= lim)
 			break;
-		pend_qsz += TIPC_SKB_CB(skb)->chain_sz;
-		skb_unlink(skb, &link->wakeupq);
-		skb_queue_tail(&link->inputq, skb);
-		link->owner->inputq = &link->inputq;
-		link->owner->action_flags |= TIPC_MSG_EVT;
+		skb_unlink(skb, &l->wakeupq);
+		skb_queue_tail(&l->inputq, skb);
+		l->owner->inputq = &l->inputq;
+		l->owner->action_flags |= TIPC_MSG_EVT;
 	}
 }
 
@@ -422,31 +404,42 @@ void tipc_link_reset_fragments(struct tipc_link *l_ptr)
 	l_ptr->reasm_buf = NULL;
 }
 
+static void tipc_link_purge_backlog(struct tipc_link *l)
+{
+	__skb_queue_purge(&l->backlogq);
+	l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
+	l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
+	l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
+	l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
+	l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
+}
+
 /**
  * tipc_link_purge_queues - purge all pkt queues associated with link
  * @l_ptr: pointer to link
  */
 void tipc_link_purge_queues(struct tipc_link *l_ptr)
 {
-	__skb_queue_purge(&l_ptr->deferred_queue);
-	__skb_queue_purge(&l_ptr->outqueue);
+	__skb_queue_purge(&l_ptr->deferdq);
+	__skb_queue_purge(&l_ptr->transmq);
+	tipc_link_purge_backlog(l_ptr);
 	tipc_link_reset_fragments(l_ptr);
 }
 
 void tipc_link_reset(struct tipc_link *l_ptr)
 {
 	u32 prev_state = l_ptr->state;
-	u32 checkpoint = l_ptr->next_in_no;
 	int was_active_link = tipc_link_is_active(l_ptr);
 	struct tipc_node *owner = l_ptr->owner;
+	struct tipc_link *pl = tipc_parallel_link(l_ptr);
 
 	msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
 
 	/* Link is down, accept any session */
 	l_ptr->peer_session = INVALID_SESSION;
 
-	/* Prepare for max packet size negotiation */
-	link_init_max_pkt(l_ptr);
+	/* Prepare for renewed mtu size negotiation */
+	l_ptr->mtu = l_ptr->advertised_mtu;
 
 	l_ptr->state = RESET_UNKNOWN;
 
@@ -456,21 +449,26 @@ void tipc_link_reset(struct tipc_link *l_ptr)
 	tipc_node_link_down(l_ptr->owner, l_ptr);
 	tipc_bearer_remove_dest(owner->net, l_ptr->bearer_id, l_ptr->addr);
 
-	if (was_active_link && tipc_node_active_links(l_ptr->owner)) {
-		l_ptr->reset_checkpoint = checkpoint;
-		l_ptr->exp_msg_count = START_CHANGEOVER;
+	if (was_active_link && tipc_node_is_up(l_ptr->owner) && (pl != l_ptr)) {
+		l_ptr->flags |= LINK_FAILINGOVER;
+		l_ptr->failover_checkpt = l_ptr->next_in_no;
+		pl->failover_pkts = FIRST_FAILOVER;
+		pl->failover_checkpt = l_ptr->next_in_no;
+		pl->failover_skb = l_ptr->reasm_buf;
+	} else {
+		kfree_skb(l_ptr->reasm_buf);
 	}
-
 	/* Clean up all queues, except inputq: */
-	__skb_queue_purge(&l_ptr->outqueue);
-	__skb_queue_purge(&l_ptr->deferred_queue);
+	__skb_queue_purge(&l_ptr->transmq);
+	__skb_queue_purge(&l_ptr->deferdq);
 	if (!owner->inputq)
 		owner->inputq = &l_ptr->inputq;
 	skb_queue_splice_init(&l_ptr->wakeupq, owner->inputq);
 	if (!skb_queue_empty(owner->inputq))
 		owner->action_flags |= TIPC_MSG_EVT;
-	l_ptr->next_out = NULL;
-	l_ptr->unacked_window = 0;
+	tipc_link_purge_backlog(l_ptr);
+	l_ptr->reasm_buf = NULL;
+	l_ptr->rcv_unacked = 0;
 	l_ptr->checkpoint = 1;
 	l_ptr->next_out_no = 1;
 	l_ptr->fsm_msg_cnt = 0;
@@ -521,8 +519,7 @@ static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 	if (!(l_ptr->flags & LINK_STARTED) && (event != STARTING_EVT))
 		return;		/* Not yet. */
 
-	/* Check whether changeover is going on */
-	if (l_ptr->exp_msg_count) {
+	if (l_ptr->flags & LINK_FAILINGOVER) {
 		if (event == TIMEOUT_EVT)
 			link_set_timer(l_ptr, cont_intv);
 		return;
@@ -539,11 +536,7 @@ static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 				l_ptr->checkpoint = l_ptr->next_in_no;
 				if (tipc_bclink_acks_missing(l_ptr->owner)) {
 					tipc_link_proto_xmit(l_ptr, STATE_MSG,
-							     0, 0, 0, 0, 0);
-					l_ptr->fsm_msg_cnt++;
-				} else if (l_ptr->max_pkt < l_ptr->max_pkt_target) {
-					tipc_link_proto_xmit(l_ptr, STATE_MSG,
-							     1, 0, 0, 0, 0);
+							     0, 0, 0, 0);
 					l_ptr->fsm_msg_cnt++;
 				}
 				link_set_timer(l_ptr, cont_intv);
@@ -551,7 +544,7 @@ static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 			}
 			l_ptr->state = WORKING_UNKNOWN;
 			l_ptr->fsm_msg_cnt = 0;
-			tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
+			tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 			l_ptr->fsm_msg_cnt++;
 			link_set_timer(l_ptr, cont_intv / 4);
 			break;
@@ -562,7 +555,7 @@ static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 			l_ptr->state = RESET_RESET;
 			l_ptr->fsm_msg_cnt = 0;
 			tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
-					     0, 0, 0, 0, 0);
+					     0, 0, 0, 0);
 			l_ptr->fsm_msg_cnt++;
 			link_set_timer(l_ptr, cont_intv);
 			break;
@@ -585,7 +578,7 @@ static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 			l_ptr->state = RESET_RESET;
 			l_ptr->fsm_msg_cnt = 0;
 			tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
-					     0, 0, 0, 0, 0);
+					     0, 0, 0, 0);
 			l_ptr->fsm_msg_cnt++;
 			link_set_timer(l_ptr, cont_intv);
 			break;
@@ -596,13 +589,13 @@ static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 				l_ptr->checkpoint = l_ptr->next_in_no;
 				if (tipc_bclink_acks_missing(l_ptr->owner)) {
 					tipc_link_proto_xmit(l_ptr, STATE_MSG,
-							     0, 0, 0, 0, 0);
+							     0, 0, 0, 0);
 					l_ptr->fsm_msg_cnt++;
 				}
 				link_set_timer(l_ptr, cont_intv);
 			} else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) {
 				tipc_link_proto_xmit(l_ptr, STATE_MSG,
-						     1, 0, 0, 0, 0);
+						     1, 0, 0, 0);
 				l_ptr->fsm_msg_cnt++;
 				link_set_timer(l_ptr, cont_intv / 4);
 			} else {	/* Link has failed */
@@ -612,7 +605,7 @@ static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 				l_ptr->state = RESET_UNKNOWN;
 				l_ptr->fsm_msg_cnt = 0;
 				tipc_link_proto_xmit(l_ptr, RESET_MSG,
-						     0, 0, 0, 0, 0);
+						     0, 0, 0, 0);
 				l_ptr->fsm_msg_cnt++;
 				link_set_timer(l_ptr, cont_intv);
 			}
@@ -632,7 +625,7 @@ static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 			l_ptr->state = WORKING_WORKING;
 			l_ptr->fsm_msg_cnt = 0;
 			link_activate(l_ptr);
-			tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
+			tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 			l_ptr->fsm_msg_cnt++;
 			if (l_ptr->owner->working_links == 1)
 				tipc_link_sync_xmit(l_ptr);
@@ -642,7 +635,7 @@ static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 			l_ptr->state = RESET_RESET;
 			l_ptr->fsm_msg_cnt = 0;
 			tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
-					     1, 0, 0, 0, 0);
+					     1, 0, 0, 0);
 			l_ptr->fsm_msg_cnt++;
 			link_set_timer(l_ptr, cont_intv);
 			break;
@@ -652,7 +645,7 @@ static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 			link_set_timer(l_ptr, cont_intv);
 			break;
 		case TIMEOUT_EVT:
-			tipc_link_proto_xmit(l_ptr, RESET_MSG, 0, 0, 0, 0, 0);
+			tipc_link_proto_xmit(l_ptr, RESET_MSG, 0, 0, 0, 0);
 			l_ptr->fsm_msg_cnt++;
 			link_set_timer(l_ptr, cont_intv);
 			break;
@@ -670,7 +663,7 @@ static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 			l_ptr->state = WORKING_WORKING;
 			l_ptr->fsm_msg_cnt = 0;
 			link_activate(l_ptr);
-			tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
+			tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 			l_ptr->fsm_msg_cnt++;
 			if (l_ptr->owner->working_links == 1)
 				tipc_link_sync_xmit(l_ptr);
@@ -680,7 +673,7 @@ static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 			break;
 		case TIMEOUT_EVT:
 			tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
-					     0, 0, 0, 0, 0);
+					     0, 0, 0, 0);
 			l_ptr->fsm_msg_cnt++;
 			link_set_timer(l_ptr, cont_intv);
 			break;
@@ -693,101 +686,65 @@ static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 	}
 }
 
-/* tipc_link_cong: determine return value and how to treat the
- * sent buffer during link congestion.
- * - For plain, errorless user data messages we keep the buffer and
- *   return -ELINKONG.
- * - For all other messages we discard the buffer and return -EHOSTUNREACH
- * - For TIPC internal messages we also reset the link
- */
-static int tipc_link_cong(struct tipc_link *link, struct sk_buff_head *list)
-{
-	struct sk_buff *skb = skb_peek(list);
-	struct tipc_msg *msg = buf_msg(skb);
-	uint imp = tipc_msg_tot_importance(msg);
-	u32 oport = msg_tot_origport(msg);
-
-	if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
-		pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
-		tipc_link_reset(link);
-		goto drop;
-	}
-	if (unlikely(msg_errcode(msg)))
-		goto drop;
-	if (unlikely(msg_reroute_cnt(msg)))
-		goto drop;
-	if (TIPC_SKB_CB(skb)->wakeup_pending)
-		return -ELINKCONG;
-	if (link_schedule_user(link, oport, skb_queue_len(list), imp))
-		return -ELINKCONG;
-drop:
-	__skb_queue_purge(list);
-	return -EHOSTUNREACH;
-}
-
 /**
  * __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked
  * @link: link to use
  * @list: chain of buffers containing message
  *
- * Consumes the buffer chain, except when returning -ELINKCONG
- * Returns 0 if success, otherwise errno: -ELINKCONG, -EMSGSIZE (plain socket
- * user data messages) or -EHOSTUNREACH (all other messages/senders)
- * Only the socket functions tipc_send_stream() and tipc_send_packet() need
- * to act on the return value, since they may need to do more send attempts.
+ * Consumes the buffer chain, except when returning -ELINKCONG,
+ * since the caller then may want to make more send attempts.
+ * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
+ * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
  */
 int __tipc_link_xmit(struct net *net, struct tipc_link *link,
 		     struct sk_buff_head *list)
 {
 	struct tipc_msg *msg = buf_msg(skb_peek(list));
-	uint psz = msg_size(msg);
-	uint sndlim = link->queue_limit[0];
-	uint imp = tipc_msg_tot_importance(msg);
-	uint mtu = link->max_pkt;
+	unsigned int maxwin = link->window;
+	unsigned int imp = msg_importance(msg);
+	uint mtu = link->mtu;
 	uint ack = mod(link->next_in_no - 1);
 	uint seqno = link->next_out_no;
 	uint bc_last_in = link->owner->bclink.last_in;
 	struct tipc_media_addr *addr = &link->media_addr;
-	struct sk_buff_head *outqueue = &link->outqueue;
+	struct sk_buff_head *transmq = &link->transmq;
+	struct sk_buff_head *backlogq = &link->backlogq;
 	struct sk_buff *skb, *tmp;
 
-	/* Match queue limits against msg importance: */
-	if (unlikely(skb_queue_len(outqueue) >= link->queue_limit[imp]))
-		return tipc_link_cong(link, list);
+	/* Match backlog limit against msg importance: */
+	if (unlikely(link->backlog[imp].len >= link->backlog[imp].limit))
+		return link_schedule_user(link, list);
 
-	/* Has valid packet limit been used ? */
-	if (unlikely(psz > mtu)) {
+	if (unlikely(msg_size(msg) > mtu)) {
 		__skb_queue_purge(list);
 		return -EMSGSIZE;
 	}
-
-	/* Prepare each packet for sending, and add to outqueue: */
+	/* Prepare each packet for sending, and add to relevant queue: */
 	skb_queue_walk_safe(list, skb, tmp) {
 		__skb_unlink(skb, list);
 		msg = buf_msg(skb);
-		msg_set_word(msg, 2, ((ack << 16) | mod(seqno)));
+		msg_set_seqno(msg, seqno);
+		msg_set_ack(msg, ack);
 		msg_set_bcast_ack(msg, bc_last_in);
 
-		if (skb_queue_len(outqueue) < sndlim) {
-			__skb_queue_tail(outqueue, skb);
-			tipc_bearer_send(net, link->bearer_id,
-					 skb, addr);
-			link->next_out = NULL;
-			link->unacked_window = 0;
-		} else if (tipc_msg_bundle(outqueue, skb, mtu)) {
+		if (likely(skb_queue_len(transmq) < maxwin)) {
+			__skb_queue_tail(transmq, skb);
+			tipc_bearer_send(net, link->bearer_id, skb, addr);
+			link->rcv_unacked = 0;
+			seqno++;
+			continue;
+		}
+		if (tipc_msg_bundle(skb_peek_tail(backlogq), skb, mtu)) {
 			link->stats.sent_bundled++;
 			continue;
-		} else if (tipc_msg_make_bundle(outqueue, skb, mtu,
-						link->addr)) {
+		}
+		if (tipc_msg_make_bundle(&skb, mtu, link->addr)) {
 			link->stats.sent_bundled++;
 			link->stats.sent_bundles++;
-			if (!link->next_out)
-				link->next_out = skb_peek_tail(outqueue);
-		} else {
-			__skb_queue_tail(outqueue, skb);
-			if (!link->next_out)
-				link->next_out = skb;
+			imp = msg_importance(buf_msg(skb));
 		}
+		__skb_queue_tail(backlogq, skb);
+		link->backlog[imp].len++;
 		seqno++;
 	}
 	link->next_out_no = seqno;
@@ -808,13 +765,25 @@ static int __tipc_link_xmit_skb(struct tipc_link *link, struct sk_buff *skb)
 	return __tipc_link_xmit(link->owner->net, link, &head);
 }
 
+/* tipc_link_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_link_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
 		       u32 selector)
 {
 	struct sk_buff_head head;
+	int rc;
 
 	skb2list(skb, &head);
-	return tipc_link_xmit(net, &head, dnode, selector);
+	rc = tipc_link_xmit(net, &head, dnode, selector);
+	if (rc == -ELINKCONG)
+		kfree_skb(skb);
+	return 0;
 }
 
 /**
@@ -841,12 +810,15 @@ int tipc_link_xmit(struct net *net, struct sk_buff_head *list, u32 dnode,
 		if (link)
 			rc = __tipc_link_xmit(net, link, list);
 		tipc_node_unlock(node);
+		tipc_node_put(node);
 	}
 	if (link)
 		return rc;
 
-	if (likely(in_own_node(net, dnode)))
-		return tipc_sk_rcv(net, list);
+	if (likely(in_own_node(net, dnode))) {
+		tipc_sk_rcv(net, list);
+		return 0;
+	}
 
 	__skb_queue_purge(list);
 	return rc;
@@ -893,14 +865,6 @@ static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf)
 	kfree_skb(buf);
 }
 
-struct sk_buff *tipc_skb_queue_next(const struct sk_buff_head *list,
-				    const struct sk_buff *skb)
-{
-	if (skb_queue_is_last(list, skb))
-		return NULL;
-	return skb->next;
-}
-
 /*
  * tipc_link_push_packets - push unsent packets to bearer
  *
@@ -909,30 +873,24 @@ struct sk_buff *tipc_skb_queue_next(const struct sk_buff_head *list,
  *
  * Called with node locked
  */
-void tipc_link_push_packets(struct tipc_link *l_ptr)
+void tipc_link_push_packets(struct tipc_link *link)
 {
-	struct sk_buff_head *outqueue = &l_ptr->outqueue;
-	struct sk_buff *skb = l_ptr->next_out;
+	struct sk_buff *skb;
 	struct tipc_msg *msg;
-	u32 next, first;
+	unsigned int ack = mod(link->next_in_no - 1);
 
-	skb_queue_walk_from(outqueue, skb) {
-		msg = buf_msg(skb);
-		next = msg_seqno(msg);
-		first = buf_seqno(skb_peek(outqueue));
-
-		if (mod(next - first) < l_ptr->queue_limit[0]) {
-			msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
-			msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
-			if (msg_user(msg) == MSG_BUNDLER)
-				TIPC_SKB_CB(skb)->bundling = false;
-			tipc_bearer_send(l_ptr->owner->net,
-					 l_ptr->bearer_id, skb,
-					 &l_ptr->media_addr);
-			l_ptr->next_out = tipc_skb_queue_next(outqueue, skb);
-		} else {
+	while (skb_queue_len(&link->transmq) < link->window) {
+		skb = __skb_dequeue(&link->backlogq);
+		if (!skb)
 			break;
-		}
+		msg = buf_msg(skb);
+		link->backlog[msg_importance(msg)].len--;
+		msg_set_ack(msg, ack);
+		msg_set_bcast_ack(msg, link->owner->bclink.last_in);
+		link->rcv_unacked = 0;
+		__skb_queue_tail(&link->transmq, skb);
+		tipc_bearer_send(link->owner->net, link->bearer_id,
+				 skb, &link->media_addr);
 	}
 }
 
@@ -979,7 +937,6 @@ static void link_retransmit_failure(struct tipc_link *l_ptr,
 			(unsigned long) TIPC_SKB_CB(buf)->handle);
 
 		n_ptr = tipc_bclink_retransmit_to(net);
-		tipc_node_lock(n_ptr);
 
 		tipc_addr_string_fill(addr_string, n_ptr->addr);
 		pr_info("Broadcast link info for %s\n", addr_string);
@@ -991,9 +948,7 @@ static void link_retransmit_failure(struct tipc_link *l_ptr,
 			n_ptr->bclink.oos_state,
 			n_ptr->bclink.last_sent);
 
-		tipc_node_unlock(n_ptr);
-
-		tipc_bclink_set_flags(net, TIPC_BCLINK_RESET);
+		n_ptr->action_flags |= TIPC_BCAST_RESET;
 		l_ptr->stale_count = 0;
 	}
 }
@@ -1019,8 +974,8 @@ void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
 		l_ptr->stale_count = 1;
 	}
 
-	skb_queue_walk_from(&l_ptr->outqueue, skb) {
-		if (!retransmits || skb == l_ptr->next_out)
+	skb_queue_walk_from(&l_ptr->transmq, skb) {
+		if (!retransmits)
 			break;
 		msg = buf_msg(skb);
 		msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
@@ -1032,72 +987,43 @@ void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
 	}
 }
 
-static void link_retrieve_defq(struct tipc_link *link,
-			       struct sk_buff_head *list)
-{
-	u32 seq_no;
-
-	if (skb_queue_empty(&link->deferred_queue))
-		return;
-
-	seq_no = buf_seqno(skb_peek(&link->deferred_queue));
-	if (seq_no == mod(link->next_in_no))
-		skb_queue_splice_tail_init(&link->deferred_queue, list);
-}
-
-/**
- * link_recv_buf_validate - validate basic format of received message
- *
- * This routine ensures a TIPC message has an acceptable header, and at least
- * as much data as the header indicates it should.  The routine also ensures
- * that the entire message header is stored in the main fragment of the message
- * buffer, to simplify future access to message header fields.
- *
- * Note: Having extra info present in the message header or data areas is OK.
- * TIPC will ignore the excess, under the assumption that it is optional info
- * introduced by a later release of the protocol.
+/* link_synch(): check if all packets arrived before the synch
+ *               point have been consumed
+ * Returns true if the parallel links are synched, otherwise false
  */
-static int link_recv_buf_validate(struct sk_buff *buf)
+static bool link_synch(struct tipc_link *l)
 {
-	static u32 min_data_hdr_size[8] = {
-		SHORT_H_SIZE, MCAST_H_SIZE, NAMED_H_SIZE, BASIC_H_SIZE,
-		MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE
-		};
+	unsigned int post_synch;
+	struct tipc_link *pl;
 
-	struct tipc_msg *msg;
-	u32 tipc_hdr[2];
-	u32 size;
-	u32 hdr_size;
-	u32 min_hdr_size;
+	pl  = tipc_parallel_link(l);
+	if (pl == l)
+		goto synched;
 
-	/* If this packet comes from the defer queue, the skb has already
-	 * been validated
-	 */
-	if (unlikely(TIPC_SKB_CB(buf)->deferred))
-		return 1;
-
-	if (unlikely(buf->len < MIN_H_SIZE))
-		return 0;
-
-	msg = skb_header_pointer(buf, 0, sizeof(tipc_hdr), tipc_hdr);
-	if (msg == NULL)
-		return 0;
+	/* Was last pre-synch packet added to input queue ? */
+	if (less_eq(pl->next_in_no, l->synch_point))
+		return false;
 
-	if (unlikely(msg_version(msg) != TIPC_VERSION))
-		return 0;
+	/* Is it still in the input queue ? */
+	post_synch = mod(pl->next_in_no - l->synch_point) - 1;
+	if (skb_queue_len(&pl->inputq) > post_synch)
+		return false;
+synched:
+	l->flags &= ~LINK_SYNCHING;
+	return true;
+}
 
-	size = msg_size(msg);
-	hdr_size = msg_hdr_sz(msg);
-	min_hdr_size = msg_isdata(msg) ?
-		min_data_hdr_size[msg_type(msg)] : INT_H_SIZE;
+static void link_retrieve_defq(struct tipc_link *link,
+			       struct sk_buff_head *list)
+{
+	u32 seq_no;
 
-	if (unlikely((hdr_size < min_hdr_size) ||
-		     (size < hdr_size) ||
-		     (buf->len < size) ||
-		     (size - hdr_size > TIPC_MAX_USER_MSG_SIZE)))
-		return 0;
+	if (skb_queue_empty(&link->deferdq))
+		return;
 
-	return pskb_may_pull(buf, hdr_size);
+	seq_no = buf_seqno(skb_peek(&link->deferdq));
+	if (seq_no == mod(link->next_in_no))
+		skb_queue_splice_tail_init(&link->deferdq, list);
 }
 
 /**
@@ -1125,16 +1051,11 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr)
 
 	while ((skb = __skb_dequeue(&head))) {
 		/* Ensure message is well-formed */
-		if (unlikely(!link_recv_buf_validate(skb)))
-			goto discard;
-
-		/* Ensure message data is a single contiguous unit */
-		if (unlikely(skb_linearize(skb)))
+		if (unlikely(!tipc_msg_validate(skb)))
 			goto discard;
 
 		/* Handle arrival of a non-unicast link message */
 		msg = buf_msg(skb);
-
 		if (unlikely(msg_non_seq(msg))) {
 			if (msg_user(msg) ==  LINK_CONFIG)
 				tipc_disc_rcv(net, skb, b_ptr);
@@ -1152,8 +1073,8 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr)
 		n_ptr = tipc_node_find(net, msg_prevnode(msg));
 		if (unlikely(!n_ptr))
 			goto discard;
-		tipc_node_lock(n_ptr);
 
+		tipc_node_lock(n_ptr);
 		/* Locate unicast link endpoint that should handle message */
 		l_ptr = n_ptr->links[b_ptr->identity];
 		if (unlikely(!l_ptr))
@@ -1175,21 +1096,20 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr)
 		ackd = msg_ack(msg);
 
 		/* Release acked messages */
-		if (n_ptr->bclink.recv_permitted)
+		if (unlikely(n_ptr->bclink.acked != msg_bcast_ack(msg)))
 			tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
 
 		released = 0;
-		skb_queue_walk_safe(&l_ptr->outqueue, skb1, tmp) {
-			if (skb1 == l_ptr->next_out ||
-			    more(buf_seqno(skb1), ackd))
+		skb_queue_walk_safe(&l_ptr->transmq, skb1, tmp) {
+			if (more(buf_seqno(skb1), ackd))
 				break;
-			 __skb_unlink(skb1, &l_ptr->outqueue);
+			 __skb_unlink(skb1, &l_ptr->transmq);
 			 kfree_skb(skb1);
 			 released = 1;
 		}
 
 		/* Try sending any messages link endpoint has pending */
-		if (unlikely(l_ptr->next_out))
+		if (unlikely(skb_queue_len(&l_ptr->backlogq)))
 			tipc_link_push_packets(l_ptr);
 
 		if (released && !skb_queue_empty(&l_ptr->wakeupq))
@@ -1223,18 +1143,26 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr)
 			skb = NULL;
 			goto unlock;
 		}
+		/* Synchronize with parallel link if applicable */
+		if (unlikely((l_ptr->flags & LINK_SYNCHING) && !msg_dup(msg))) {
+			link_handle_out_of_seq_msg(l_ptr, skb);
+			if (link_synch(l_ptr))
+				link_retrieve_defq(l_ptr, &head);
+			skb = NULL;
+			goto unlock;
+		}
 		l_ptr->next_in_no++;
-		if (unlikely(!skb_queue_empty(&l_ptr->deferred_queue)))
+		if (unlikely(!skb_queue_empty(&l_ptr->deferdq)))
 			link_retrieve_defq(l_ptr, &head);
-
-		if (unlikely(++l_ptr->unacked_window >= TIPC_MIN_LINK_WIN)) {
+		if (unlikely(++l_ptr->rcv_unacked >= TIPC_MIN_LINK_WIN)) {
 			l_ptr->stats.sent_acks++;
-			tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
+			tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0);
 		}
 		tipc_link_input(l_ptr, skb);
 		skb = NULL;
 unlock:
 		tipc_node_unlock(n_ptr);
+		tipc_node_put(n_ptr);
 discard:
 		if (unlikely(skb))
 			kfree_skb(skb);
@@ -1271,7 +1199,7 @@ static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb)
 			node->action_flags |= TIPC_NAMED_MSG_EVT;
 		return true;
 	case MSG_BUNDLER:
-	case CHANGEOVER_PROTOCOL:
+	case TUNNEL_PROTOCOL:
 	case MSG_FRAGMENTER:
 	case BCAST_PROTOCOL:
 		return false;
@@ -1298,8 +1226,14 @@ static void tipc_link_input(struct tipc_link *link, struct sk_buff *skb)
 		return;
 
 	switch (msg_user(msg)) {
-	case CHANGEOVER_PROTOCOL:
-		if (!tipc_link_tunnel_rcv(node, &skb))
+	case TUNNEL_PROTOCOL:
+		if (msg_dup(msg)) {
+			link->flags |= LINK_SYNCHING;
+			link->synch_point = msg_seqno(msg_get_wrapped(msg));
+			kfree_skb(skb);
+			break;
+		}
+		if (!tipc_link_failover_rcv(link, &skb))
 			break;
 		if (msg_user(buf_msg(skb)) != MSG_BUNDLER) {
 			tipc_data_input(link, skb);
@@ -1394,11 +1328,10 @@ static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
 		return;
 	}
 
-	if (tipc_link_defer_pkt(&l_ptr->deferred_queue, buf)) {
+	if (tipc_link_defer_pkt(&l_ptr->deferdq, buf)) {
 		l_ptr->stats.deferred_recv++;
-		TIPC_SKB_CB(buf)->deferred = true;
-		if ((skb_queue_len(&l_ptr->deferred_queue) % 16) == 1)
-			tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
+		if ((skb_queue_len(&l_ptr->deferdq) % TIPC_MIN_LINK_WIN) == 1)
+			tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0);
 	} else {
 		l_ptr->stats.duplicates++;
 	}
@@ -1408,15 +1341,15 @@ static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
  * Send protocol message to the other endpoint.
  */
 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int probe_msg,
-			  u32 gap, u32 tolerance, u32 priority, u32 ack_mtu)
+			  u32 gap, u32 tolerance, u32 priority)
 {
 	struct sk_buff *buf = NULL;
 	struct tipc_msg *msg = l_ptr->pmsg;
 	u32 msg_size = sizeof(l_ptr->proto_msg);
 	int r_flag;
 
-	/* Don't send protocol message during link changeover */
-	if (l_ptr->exp_msg_count)
+	/* Don't send protocol message during link failover */
+	if (l_ptr->flags & LINK_FAILINGOVER)
 		return;
 
 	/* Abort non-RESET send if communication with node is prohibited */
@@ -1434,11 +1367,11 @@ void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int probe_msg,
 
 		if (!tipc_link_is_up(l_ptr))
 			return;
-		if (l_ptr->next_out)
-			next_sent = buf_seqno(l_ptr->next_out);
+		if (skb_queue_len(&l_ptr->backlogq))
+			next_sent = buf_seqno(skb_peek(&l_ptr->backlogq));
 		msg_set_next_sent(msg, next_sent);
-		if (!skb_queue_empty(&l_ptr->deferred_queue)) {
-			u32 rec = buf_seqno(skb_peek(&l_ptr->deferred_queue));
+		if (!skb_queue_empty(&l_ptr->deferdq)) {
+			u32 rec = buf_seqno(skb_peek(&l_ptr->deferdq));
 			gap = mod(rec - mod(l_ptr->next_in_no));
 		}
 		msg_set_seq_gap(msg, gap);
@@ -1446,35 +1379,20 @@ void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int probe_msg,
 			l_ptr->stats.sent_nacks++;
 		msg_set_link_tolerance(msg, tolerance);
 		msg_set_linkprio(msg, priority);
-		msg_set_max_pkt(msg, ack_mtu);
+		msg_set_max_pkt(msg, l_ptr->mtu);
 		msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
 		msg_set_probe(msg, probe_msg != 0);
-		if (probe_msg) {
-			u32 mtu = l_ptr->max_pkt;
-
-			if ((mtu < l_ptr->max_pkt_target) &&
-			    link_working_working(l_ptr) &&
-			    l_ptr->fsm_msg_cnt) {
-				msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
-				if (l_ptr->max_pkt_probes == 10) {
-					l_ptr->max_pkt_target = (msg_size - 4);
-					l_ptr->max_pkt_probes = 0;
-					msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
-				}
-				l_ptr->max_pkt_probes++;
-			}
-
+		if (probe_msg)
 			l_ptr->stats.sent_probes++;
-		}
 		l_ptr->stats.sent_states++;
 	} else {		/* RESET_MSG or ACTIVATE_MSG */
-		msg_set_ack(msg, mod(l_ptr->reset_checkpoint - 1));
+		msg_set_ack(msg, mod(l_ptr->failover_checkpt - 1));
 		msg_set_seq_gap(msg, 0);
 		msg_set_next_sent(msg, 1);
 		msg_set_probe(msg, 0);
 		msg_set_link_tolerance(msg, l_ptr->tolerance);
 		msg_set_linkprio(msg, l_ptr->priority);
-		msg_set_max_pkt(msg, l_ptr->max_pkt_target);
+		msg_set_max_pkt(msg, l_ptr->advertised_mtu);
 	}
 
 	r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr));
@@ -1490,10 +1408,9 @@ void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int probe_msg,
 
 	skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
 	buf->priority = TC_PRIO_CONTROL;
-
 	tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, buf,
 			 &l_ptr->media_addr);
-	l_ptr->unacked_window = 0;
+	l_ptr->rcv_unacked = 0;
 	kfree_skb(buf);
 }
 
@@ -1506,13 +1423,10 @@ static void tipc_link_proto_rcv(struct tipc_link *l_ptr,
 				struct sk_buff *buf)
 {
 	u32 rec_gap = 0;
-	u32 max_pkt_info;
-	u32 max_pkt_ack;
 	u32 msg_tol;
 	struct tipc_msg *msg = buf_msg(buf);
 
-	/* Discard protocol message during link changeover */
-	if (l_ptr->exp_msg_count)
+	if (l_ptr->flags & LINK_FAILINGOVER)
 		goto exit;
 
 	if (l_ptr->net_plane != msg_net_plane(msg))
@@ -1551,15 +1465,8 @@ static void tipc_link_proto_rcv(struct tipc_link *l_ptr,
 		if (msg_linkprio(msg) > l_ptr->priority)
 			l_ptr->priority = msg_linkprio(msg);
 
-		max_pkt_info = msg_max_pkt(msg);
-		if (max_pkt_info) {
-			if (max_pkt_info < l_ptr->max_pkt_target)
-				l_ptr->max_pkt_target = max_pkt_info;
-			if (l_ptr->max_pkt > l_ptr->max_pkt_target)
-				l_ptr->max_pkt = l_ptr->max_pkt_target;
-		} else {
-			l_ptr->max_pkt = l_ptr->max_pkt_target;
-		}
+		if (l_ptr->mtu > msg_max_pkt(msg))
+			l_ptr->mtu = msg_max_pkt(msg);
 
 		/* Synchronize broadcast link info, if not done previously */
 		if (!tipc_node_is_up(l_ptr->owner)) {
@@ -1604,18 +1511,8 @@ static void tipc_link_proto_rcv(struct tipc_link *l_ptr,
 				      mod(l_ptr->next_in_no));
 		}
 
-		max_pkt_ack = msg_max_pkt(msg);
-		if (max_pkt_ack > l_ptr->max_pkt) {
-			l_ptr->max_pkt = max_pkt_ack;
-			l_ptr->max_pkt_probes = 0;
-		}
-
-		max_pkt_ack = 0;
-		if (msg_probe(msg)) {
+		if (msg_probe(msg))
 			l_ptr->stats.recv_probes++;
-			if (msg_size(msg) > sizeof(l_ptr->proto_msg))
-				max_pkt_ack = msg_size(msg);
-		}
 
 		/* Protocol message before retransmits, reduce loss risk */
 		if (l_ptr->owner->bclink.recv_permitted)
@@ -1623,12 +1520,12 @@ static void tipc_link_proto_rcv(struct tipc_link *l_ptr,
 						      msg_last_bcast(msg));
 
 		if (rec_gap || (msg_probe(msg))) {
-			tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, rec_gap, 0,
-					     0, max_pkt_ack);
+			tipc_link_proto_xmit(l_ptr, STATE_MSG, 0,
+					     rec_gap, 0, 0);
 		}
 		if (msg_seq_gap(msg)) {
 			l_ptr->stats.recv_nacks++;
-			tipc_link_retransmit(l_ptr, skb_peek(&l_ptr->outqueue),
+			tipc_link_retransmit(l_ptr, skb_peek(&l_ptr->transmq),
 					     msg_seq_gap(msg));
 		}
 		break;
@@ -1675,7 +1572,7 @@ static void tipc_link_tunnel_xmit(struct tipc_link *l_ptr,
  */
 void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
 {
-	u32 msgcount = skb_queue_len(&l_ptr->outqueue);
+	int msgcount;
 	struct tipc_link *tunnel = l_ptr->owner->active_links[0];
 	struct tipc_msg tunnel_hdr;
 	struct sk_buff *skb;
@@ -1684,12 +1581,15 @@ void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
 	if (!tunnel)
 		return;
 
-	tipc_msg_init(link_own_addr(l_ptr), &tunnel_hdr, CHANGEOVER_PROTOCOL,
-		      ORIGINAL_MSG, INT_H_SIZE, l_ptr->addr);
+	tipc_msg_init(link_own_addr(l_ptr), &tunnel_hdr, TUNNEL_PROTOCOL,
+		      FAILOVER_MSG, INT_H_SIZE, l_ptr->addr);
+	skb_queue_splice_tail_init(&l_ptr->backlogq, &l_ptr->transmq);
+	tipc_link_purge_backlog(l_ptr);
+	msgcount = skb_queue_len(&l_ptr->transmq);
 	msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
 	msg_set_msgcnt(&tunnel_hdr, msgcount);
 
-	if (skb_queue_empty(&l_ptr->outqueue)) {
+	if (skb_queue_empty(&l_ptr->transmq)) {
 		skb = tipc_buf_acquire(INT_H_SIZE);
 		if (skb) {
 			skb_copy_to_linear_data(skb, &tunnel_hdr, INT_H_SIZE);
@@ -1705,7 +1605,7 @@ void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
 	split_bundles = (l_ptr->owner->active_links[0] !=
 			 l_ptr->owner->active_links[1]);
 
-	skb_queue_walk(&l_ptr->outqueue, skb) {
+	skb_queue_walk(&l_ptr->transmq, skb) {
 		struct tipc_msg *msg = buf_msg(skb);
 
 		if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
@@ -1736,157 +1636,105 @@ void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
  * and sequence order is preserved per sender/receiver socket pair.
  * Owner node is locked.
  */
-void tipc_link_dup_queue_xmit(struct tipc_link *l_ptr,
-			      struct tipc_link *tunnel)
+void tipc_link_dup_queue_xmit(struct tipc_link *link,
+			      struct tipc_link *tnl)
 {
 	struct sk_buff *skb;
-	struct tipc_msg tunnel_hdr;
-
-	tipc_msg_init(link_own_addr(l_ptr), &tunnel_hdr, CHANGEOVER_PROTOCOL,
-		      DUPLICATE_MSG, INT_H_SIZE, l_ptr->addr);
-	msg_set_msgcnt(&tunnel_hdr, skb_queue_len(&l_ptr->outqueue));
-	msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
-	skb_queue_walk(&l_ptr->outqueue, skb) {
+	struct tipc_msg tnl_hdr;
+	struct sk_buff_head *queue = &link->transmq;
+	int mcnt;
+
+	tipc_msg_init(link_own_addr(link), &tnl_hdr, TUNNEL_PROTOCOL,
+		      SYNCH_MSG, INT_H_SIZE, link->addr);
+	mcnt = skb_queue_len(&link->transmq) + skb_queue_len(&link->backlogq);
+	msg_set_msgcnt(&tnl_hdr, mcnt);
+	msg_set_bearer_id(&tnl_hdr, link->peer_bearer_id);
+
+tunnel_queue:
+	skb_queue_walk(queue, skb) {
 		struct sk_buff *outskb;
 		struct tipc_msg *msg = buf_msg(skb);
-		u32 length = msg_size(msg);
+		u32 len = msg_size(msg);
 
-		if (msg_user(msg) == MSG_BUNDLER)
-			msg_set_type(msg, CLOSED_MSG);
-		msg_set_ack(msg, mod(l_ptr->next_in_no - 1));	/* Update */
-		msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
-		msg_set_size(&tunnel_hdr, length + INT_H_SIZE);
-		outskb = tipc_buf_acquire(length + INT_H_SIZE);
+		msg_set_ack(msg, mod(link->next_in_no - 1));
+		msg_set_bcast_ack(msg, link->owner->bclink.last_in);
+		msg_set_size(&tnl_hdr, len + INT_H_SIZE);
+		outskb = tipc_buf_acquire(len + INT_H_SIZE);
 		if (outskb == NULL) {
 			pr_warn("%sunable to send duplicate msg\n",
 				link_co_err);
 			return;
 		}
-		skb_copy_to_linear_data(outskb, &tunnel_hdr, INT_H_SIZE);
-		skb_copy_to_linear_data_offset(outskb, INT_H_SIZE, skb->data,
-					       length);
-		__tipc_link_xmit_skb(tunnel, outskb);
-		if (!tipc_link_is_up(l_ptr))
+		skb_copy_to_linear_data(outskb, &tnl_hdr, INT_H_SIZE);
+		skb_copy_to_linear_data_offset(outskb, INT_H_SIZE,
+					       skb->data, len);
+		__tipc_link_xmit_skb(tnl, outskb);
+		if (!tipc_link_is_up(link))
 			return;
 	}
-}
-
-/**
- * buf_extract - extracts embedded TIPC message from another message
- * @skb: encapsulating message buffer
- * @from_pos: offset to extract from
- *
- * Returns a new message buffer containing an embedded message.  The
- * encapsulating buffer is left unchanged.
- */
-static struct sk_buff *buf_extract(struct sk_buff *skb, u32 from_pos)
-{
-	struct tipc_msg *msg = (struct tipc_msg *)(skb->data + from_pos);
-	u32 size = msg_size(msg);
-	struct sk_buff *eb;
-
-	eb = tipc_buf_acquire(size);
-	if (eb)
-		skb_copy_to_linear_data(eb, msg, size);
-	return eb;
-}
-
-/* tipc_link_dup_rcv(): Receive a tunnelled DUPLICATE_MSG packet.
- * Owner node is locked.
- */
-static void tipc_link_dup_rcv(struct tipc_link *l_ptr,
-			      struct sk_buff *t_buf)
-{
-	struct sk_buff *buf;
-
-	if (!tipc_link_is_up(l_ptr))
+	if (queue == &link->backlogq)
 		return;
-
-	buf = buf_extract(t_buf, INT_H_SIZE);
-	if (buf == NULL) {
-		pr_warn("%sfailed to extract inner dup pkt\n", link_co_err);
-		return;
-	}
-
-	/* Add buffer to deferred queue, if applicable: */
-	link_handle_out_of_seq_msg(l_ptr, buf);
+	queue = &link->backlogq;
+	goto tunnel_queue;
 }
 
-/*  tipc_link_failover_rcv(): Receive a tunnelled ORIGINAL_MSG packet
+/*  tipc_link_failover_rcv(): Receive a tunnelled FAILOVER_MSG packet
  *  Owner node is locked.
  */
-static struct sk_buff *tipc_link_failover_rcv(struct tipc_link *l_ptr,
-					      struct sk_buff *t_buf)
+static bool tipc_link_failover_rcv(struct tipc_link *link,
+				   struct sk_buff **skb)
 {
-	struct tipc_msg *t_msg = buf_msg(t_buf);
-	struct sk_buff *buf = NULL;
-	struct tipc_msg *msg;
-
-	if (tipc_link_is_up(l_ptr))
-		tipc_link_reset(l_ptr);
-
-	/* First failover packet? */
-	if (l_ptr->exp_msg_count == START_CHANGEOVER)
-		l_ptr->exp_msg_count = msg_msgcnt(t_msg);
-
-	/* Should there be an inner packet? */
-	if (l_ptr->exp_msg_count) {
-		l_ptr->exp_msg_count--;
-		buf = buf_extract(t_buf, INT_H_SIZE);
-		if (buf == NULL) {
-			pr_warn("%sno inner failover pkt\n", link_co_err);
-			goto exit;
-		}
-		msg = buf_msg(buf);
+	struct tipc_msg *msg = buf_msg(*skb);
+	struct sk_buff *iskb = NULL;
+	struct tipc_link *pl = NULL;
+	int bearer_id = msg_bearer_id(msg);
+	int pos = 0;
 
-		if (less(msg_seqno(msg), l_ptr->reset_checkpoint)) {
-			kfree_skb(buf);
-			buf = NULL;
-			goto exit;
-		}
-		if (msg_user(msg) == MSG_FRAGMENTER) {
-			l_ptr->stats.recv_fragments++;
-			tipc_buf_append(&l_ptr->reasm_buf, &buf);
-		}
+	if (msg_type(msg) != FAILOVER_MSG) {
+		pr_warn("%sunknown tunnel pkt received\n", link_co_err);
+		goto exit;
 	}
-exit:
-	if ((!l_ptr->exp_msg_count) && (l_ptr->flags & LINK_STOPPED))
-		tipc_link_delete(l_ptr);
-	return buf;
-}
+	if (bearer_id >= MAX_BEARERS)
+		goto exit;
 
-/*  tipc_link_tunnel_rcv(): Receive a tunnelled packet, sent
- *  via other link as result of a failover (ORIGINAL_MSG) or
- *  a new active link (DUPLICATE_MSG). Failover packets are
- *  returned to the active link for delivery upwards.
- *  Owner node is locked.
- */
-static int tipc_link_tunnel_rcv(struct tipc_node *n_ptr,
-				struct sk_buff **buf)
-{
-	struct sk_buff *t_buf = *buf;
-	struct tipc_link *l_ptr;
-	struct tipc_msg *t_msg = buf_msg(t_buf);
-	u32 bearer_id = msg_bearer_id(t_msg);
+	if (bearer_id == link->bearer_id)
+		goto exit;
 
-	*buf = NULL;
+	pl = link->owner->links[bearer_id];
+	if (pl && tipc_link_is_up(pl))
+		tipc_link_reset(pl);
 
-	if (bearer_id >= MAX_BEARERS)
+	if (link->failover_pkts == FIRST_FAILOVER)
+		link->failover_pkts = msg_msgcnt(msg);
+
+	/* Should we expect an inner packet? */
+	if (!link->failover_pkts)
 		goto exit;
 
-	l_ptr = n_ptr->links[bearer_id];
-	if (!l_ptr)
+	if (!tipc_msg_extract(*skb, &iskb, &pos)) {
+		pr_warn("%sno inner failover pkt\n", link_co_err);
+		*skb = NULL;
 		goto exit;
+	}
+	link->failover_pkts--;
+	*skb = NULL;
 
-	if (msg_type(t_msg) == DUPLICATE_MSG)
-		tipc_link_dup_rcv(l_ptr, t_buf);
-	else if (msg_type(t_msg) == ORIGINAL_MSG)
-		*buf = tipc_link_failover_rcv(l_ptr, t_buf);
-	else
-		pr_warn("%sunknown tunnel pkt received\n", link_co_err);
+	/* Was this packet already delivered? */
+	if (less(buf_seqno(iskb), link->failover_checkpt)) {
+		kfree_skb(iskb);
+		iskb = NULL;
+		goto exit;
+	}
+	if (msg_user(buf_msg(iskb)) == MSG_FRAGMENTER) {
+		link->stats.recv_fragments++;
+		tipc_buf_append(&link->failover_skb, &iskb);
+	}
 exit:
-	kfree_skb(t_buf);
-	return *buf != NULL;
+	if (!link->failover_pkts && pl)
+		pl->flags &= ~LINK_FAILINGOVER;
+	kfree_skb(*skb);
+	*skb = iskb;
+	return *skb;
 }
 
 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tol)
@@ -1901,23 +1749,16 @@ static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tol)
 	l_ptr->abort_limit = tol / (jiffies_to_msecs(l_ptr->cont_intv) / 4);
 }
 
-void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window)
+void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
 {
-	/* Data messages from this node, inclusive FIRST_FRAGM */
-	l_ptr->queue_limit[TIPC_LOW_IMPORTANCE] = window;
-	l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE] = (window / 3) * 4;
-	l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE] = (window / 3) * 5;
-	l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE] = (window / 3) * 6;
-	/* Transiting data messages,inclusive FIRST_FRAGM */
-	l_ptr->queue_limit[TIPC_LOW_IMPORTANCE + 4] = 300;
-	l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE + 4] = 600;
-	l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE + 4] = 900;
-	l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE + 4] = 1200;
-	l_ptr->queue_limit[CONN_MANAGER] = 1200;
-	l_ptr->queue_limit[CHANGEOVER_PROTOCOL] = 2500;
-	l_ptr->queue_limit[NAME_DISTRIBUTOR] = 3000;
-	/* FRAGMENT and LAST_FRAGMENT packets */
-	l_ptr->queue_limit[MSG_FRAGMENTER] = 4000;
+	int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
+
+	l->window = win;
+	l->backlog[TIPC_LOW_IMPORTANCE].limit      = win / 2;
+	l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = win;
+	l->backlog[TIPC_HIGH_IMPORTANCE].limit     = win / 2 * 3;
+	l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = win * 2;
+	l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
 }
 
 /* tipc_link_find_owner - locate owner node of link by link's name
@@ -2082,14 +1923,14 @@ int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info)
 
 			tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
 			link_set_supervision_props(link, tol);
-			tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0, 0);
+			tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0);
 		}
 		if (props[TIPC_NLA_PROP_PRIO]) {
 			u32 prio;
 
 			prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
 			link->priority = prio;
-			tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio, 0);
+			tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio);
 		}
 		if (props[TIPC_NLA_PROP_WIN]) {
 			u32 win;
@@ -2194,7 +2035,7 @@ static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
 	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
 			tipc_cluster_mask(tn->own_addr)))
 		goto attr_msg_full;
-	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->max_pkt))
+	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
 		goto attr_msg_full;
 	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->next_in_no))
 		goto attr_msg_full;
@@ -2216,7 +2057,7 @@ static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
 		goto prop_msg_full;
 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
-			link->queue_limit[TIPC_LOW_IMPORTANCE]))
+			link->window))
 		goto prop_msg_full;
 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
 		goto prop_msg_full;
@@ -2282,7 +2123,6 @@ int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
 	msg.seq = cb->nlh->nlmsg_seq;
 
 	rcu_read_lock();
-
 	if (prev_node) {
 		node = tipc_node_find(net, prev_node);
 		if (!node) {
@@ -2295,6 +2135,7 @@ int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
 			cb->prev_seq = 1;
 			goto out;
 		}
+		tipc_node_put(node);
 
 		list_for_each_entry_continue_rcu(node, &tn->node_list,
 						 list) {
@@ -2302,6 +2143,7 @@ int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
 			err = __tipc_nl_add_node_links(net, &msg, node,
 						       &prev_link);
 			tipc_node_unlock(node);
+			tipc_node_put(node);
 			if (err)
 				goto out;