tipc: move link synch and failover to link aggregation level

Link failover and synchronization have until now been handled by the
links themselves, forcing them to have knowledge about and to access
parallel links in order to make the two algorithms work correctly.

In this commit, we move the control part of this functionality to the
link aggregation level in node.c, which is the right location for this.
As a result, the two algorithms become easier to follow, and the link
implementation becomes simpler.

Tested-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/link.c

@@ -48,7 +48,7 @@
 /*
  * Error message prefixes
  */
-static const char *link_co_err = "Link changeover error, ";
+static const char *link_co_err = "Link tunneling error, ";
 static const char *link_rst_msg = "Resetting link ";
 static const char *link_unk_evt = "Unknown link event ";
 
@@ -139,24 +139,6 @@ static void tipc_link_build_bcast_sync_msg(struct tipc_link *l,
 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf);
 static int 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 int tipc_link_failover_rcv(struct tipc_link *l, struct sk_buff **skb);
-
-/*
- *  Simple link routines
- */
-static unsigned int align(unsigned int i)
-{
-	return (i + 3) & ~3u;
-}
-
-static struct tipc_link *tipc_parallel_link(struct tipc_link *l)
-{
-	struct tipc_node *n = l->owner;
-
-	if (node_active_link(n, 0) != l)
-		return node_active_link(n, 0);
-	return node_active_link(n, 1);
-}
 
 /*
  *  Simple non-static link routines (i.e. referenced outside this file)
@@ -394,12 +376,10 @@ static int tipc_link_fsm_evt(struct tipc_link *l, int evt,
 	/* Perform actions as decided by FSM */
 	if (actions & LINK_RESET) {
 		l->exec_mode = TIPC_LINK_BLOCKED;
-		rc |= TIPC_LINK_DOWN_EVT;
-	}
-	if (actions & LINK_ACTIVATE) {
-		l->exec_mode = TIPC_LINK_OPEN;
-		rc |= TIPC_LINK_UP_EVT;
+		rc = TIPC_LINK_DOWN_EVT;
 	}
+	if (actions & LINK_ACTIVATE)
+		rc = TIPC_LINK_UP_EVT;
 	if (actions & (SND_STATE | SND_PROBE))
 		mtyp = STATE_MSG;
 	if (actions & SND_RESET)
@@ -461,6 +441,9 @@ int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
 {
 	int rc = 0;
 
+	if (l->exec_mode == TIPC_LINK_BLOCKED)
+		return rc;
+
 	link_profile_stats(l);
 	if (l->silent_intv_cnt)
 		rc = tipc_link_fsm_evt(l, SILENCE_EVT, xmitq);
@@ -563,52 +546,42 @@ void tipc_link_purge_queues(struct tipc_link *l_ptr)
 	tipc_link_reset_fragments(l_ptr);
 }
 
-void tipc_link_reset(struct tipc_link *l_ptr)
+void tipc_link_reset(struct tipc_link *l)
 {
-	u32 prev_state = l_ptr->state;
-	struct tipc_node *owner = l_ptr->owner;
-	struct tipc_link *pl = tipc_parallel_link(l_ptr);
+	struct tipc_node *owner = l->owner;
 
-	msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
+	l->state = TIPC_LINK_RESETTING;
 
 	/* Link is down, accept any session */
-	l_ptr->peer_session = WILDCARD_SESSION;
+	l->peer_session = WILDCARD_SESSION;
 
-	/* Prepare for renewed mtu size negotiation */
-	l_ptr->mtu = l_ptr->advertised_mtu;
-
-	l_ptr->state = TIPC_LINK_RESETTING;
+	/* If peer is up, it only accepts an incremented session number */
+	msg_set_session(l->pmsg, msg_session(l->pmsg) + 1);
 
-	if ((prev_state == TIPC_LINK_RESETTING) ||
-	    (prev_state == TIPC_LINK_ESTABLISHING))
-		return;
+	/* Prepare for renewed mtu size negotiation */
+	l->mtu = l->advertised_mtu;
 
-	if (tipc_node_is_up(l_ptr->owner) && (pl != l_ptr)) {
-		l_ptr->exec_mode = TIPC_LINK_BLOCKED;
-		l_ptr->failover_checkpt = l_ptr->rcv_nxt;
-		pl->failover_pkts = FIRST_FAILOVER;
-		pl->failover_checkpt = l_ptr->rcv_nxt;
-		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->transmq);
-	__skb_queue_purge(&l_ptr->deferdq);
+	__skb_queue_purge(&l->transmq);
+	__skb_queue_purge(&l->deferdq);
 	if (!owner->inputq)
-		owner->inputq = l_ptr->inputq;
-	skb_queue_splice_init(&l_ptr->wakeupq, owner->inputq);
+		owner->inputq = l->inputq;
+	skb_queue_splice_init(&l->wakeupq, owner->inputq);
 	if (!skb_queue_empty(owner->inputq))
 		owner->action_flags |= TIPC_MSG_EVT;
-	tipc_link_purge_backlog(l_ptr);
-	l_ptr->reasm_buf = NULL;
-	l_ptr->rcv_unacked = 0;
-	l_ptr->snd_nxt = 1;
-	l_ptr->rcv_nxt = 1;
-	l_ptr->silent_intv_cnt = 0;
-	l_ptr->stats.recv_info = 0;
-	l_ptr->stale_count = 0;
-	link_reset_statistics(l_ptr);
+
+	tipc_link_purge_backlog(l);
+	kfree_skb(l->reasm_buf);
+	kfree_skb(l->failover_reasm_skb);
+	l->reasm_buf = NULL;
+	l->failover_reasm_skb = NULL;
+	l->rcv_unacked = 0;
+	l->snd_nxt = 1;
+	l->rcv_nxt = 1;
+	l->silent_intv_cnt = 0;
+	l->stats.recv_info = 0;
+	l->stale_count = 0;
+	link_reset_statistics(l);
 }
 
 /**
@@ -751,20 +724,6 @@ int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
 	return 0;
 }
 
-static void skb2list(struct sk_buff *skb, struct sk_buff_head *list)
-{
-	skb_queue_head_init(list);
-	__skb_queue_tail(list, skb);
-}
-
-static int __tipc_link_xmit_skb(struct tipc_link *link, struct sk_buff *skb)
-{
-	struct sk_buff_head head;
-
-	skb2list(skb, &head);
-	return __tipc_link_xmit(link->owner->net, link, &head);
-}
-
 /*
  * tipc_link_sync_rcv - synchronize broadcast link endpoints.
  * Receive the sequence number where we should start receiving and
@@ -955,32 +914,6 @@ static int tipc_link_retransm(struct tipc_link *l, int retransm,
 	return 0;
 }
 
-/* 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 bool link_synch(struct tipc_link *l)
-{
-	unsigned int post_synch;
-	struct tipc_link *pl;
-
-	pl  = tipc_parallel_link(l);
-	if (pl == l)
-		goto synched;
-
-	/* Was last pre-synch packet added to input queue ? */
-	if (less_eq(pl->rcv_nxt, l->synch_point))
-		return false;
-
-	/* Is it still in the input queue ? */
-	post_synch = mod(pl->rcv_nxt - l->synch_point) - 1;
-	if (skb_queue_len(pl->inputq) > post_synch)
-		return false;
-synched:
-	l->exec_mode = TIPC_LINK_OPEN;
-	return true;
-}
-
 /* tipc_data_input - deliver data and name distr msgs to upper layer
  *
  * Consumes buffer if message is of right type
@@ -1025,54 +958,59 @@ static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb)
 /* tipc_link_input - process packet that has passed link protocol check
  *
  * Consumes buffer
- * Node lock must be held
  */
-static int tipc_link_input(struct tipc_link *link, struct sk_buff *skb)
+static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb)
 {
-	struct tipc_node *node = link->owner;
-	struct tipc_msg *msg = buf_msg(skb);
+	struct tipc_node *node = l->owner;
+	struct tipc_msg *hdr = buf_msg(skb);
+	struct sk_buff **reasm_skb = &l->reasm_buf;
 	struct sk_buff *iskb;
-	int pos = 0;
+	int usr = msg_user(hdr);
 	int rc = 0;
+	int pos = 0;
+	int ipos = 0;
 
-	switch (msg_user(msg)) {
-	case TUNNEL_PROTOCOL:
-		if (msg_dup(msg)) {
-			link->exec_mode = TIPC_LINK_TUNNEL;
-			link->synch_point = msg_seqno(msg_get_wrapped(msg));
-			kfree_skb(skb);
-			break;
+	if (unlikely(usr == TUNNEL_PROTOCOL)) {
+		if (msg_type(hdr) == SYNCH_MSG) {
+			__skb_queue_purge(&l->deferdq);
+			goto drop;
 		}
-		rc |= tipc_link_failover_rcv(link, &skb);
-		if (!skb)
-			break;
-		if (msg_user(buf_msg(skb)) != MSG_BUNDLER) {
-			tipc_data_input(link, skb);
-			break;
-		}
-	case MSG_BUNDLER:
-		link->stats.recv_bundles++;
-		link->stats.recv_bundled += msg_msgcnt(msg);
+		if (!tipc_msg_extract(skb, &iskb, &ipos))
+			return rc;
+		kfree_skb(skb);
+		skb = iskb;
+		hdr = buf_msg(skb);
+		if (less(msg_seqno(hdr), l->drop_point))
+			goto drop;
+		if (tipc_data_input(l, skb))
+			return rc;
+		usr = msg_user(hdr);
+		reasm_skb = &l->failover_reasm_skb;
+	}
 
+	if (usr == MSG_BUNDLER) {
+		l->stats.recv_bundles++;
+		l->stats.recv_bundled += msg_msgcnt(hdr);
 		while (tipc_msg_extract(skb, &iskb, &pos))
-			tipc_data_input(link, iskb);
-		break;
-	case MSG_FRAGMENTER:
-		link->stats.recv_fragments++;
-		if (tipc_buf_append(&link->reasm_buf, &skb)) {
-			link->stats.recv_fragmented++;
-			tipc_data_input(link, skb);
-		} else if (!link->reasm_buf) {
-			link->exec_mode = TIPC_LINK_BLOCKED;
-			rc |= TIPC_LINK_DOWN_EVT;
+			tipc_data_input(l, iskb);
+		return rc;
+	} else if (usr == MSG_FRAGMENTER) {
+		l->stats.recv_fragments++;
+		if (tipc_buf_append(reasm_skb, &skb)) {
+			l->stats.recv_fragmented++;
+			tipc_data_input(l, skb);
+		} else if (!*reasm_skb) {
+			l->exec_mode = TIPC_LINK_BLOCKED;
+			l->state = TIPC_LINK_RESETTING;
+			rc = TIPC_LINK_DOWN_EVT;
 		}
-		break;
-	case BCAST_PROTOCOL:
+		return rc;
+	} else if (usr == BCAST_PROTOCOL) {
 		tipc_link_sync_rcv(node, skb);
-		break;
-	default:
-		break;
-	};
+		return rc;
+	}
+drop:
+	kfree_skb(skb);
 	return rc;
 }
 
@@ -1100,7 +1038,6 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
 		  struct sk_buff_head *xmitq)
 {
 	struct sk_buff_head *arrvq = &l->deferdq;
-	struct sk_buff *tmp;
 	struct tipc_msg *hdr;
 	u16 seqno, rcv_nxt;
 	int rc = 0;
@@ -1112,18 +1049,18 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
 		return rc;
 	}
 
-	skb_queue_walk_safe(arrvq, skb, tmp) {
+	while ((skb = skb_peek(arrvq))) {
 		hdr = buf_msg(skb);
 
 		/* Verify and update link state */
 		if (unlikely(msg_user(hdr) == LINK_PROTOCOL)) {
 			__skb_dequeue(arrvq);
-			rc |= tipc_link_proto_rcv(l, skb, xmitq);
+			rc = tipc_link_proto_rcv(l, skb, xmitq);
 			continue;
 		}
 
 		if (unlikely(!link_working(l))) {
-			rc |= tipc_link_fsm_evt(l, TRAFFIC_EVT, xmitq);
+			rc = tipc_link_fsm_evt(l, TRAFFIC_EVT, xmitq);
 			if (!link_working(l)) {
 				kfree_skb(__skb_dequeue(arrvq));
 				return rc;
@@ -1156,18 +1093,11 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
 			return rc;
 		}
 
-		/* Synchronize with parallel link if applicable */
-		if (unlikely(l->exec_mode == TIPC_LINK_TUNNEL))
-			if (!msg_dup(hdr) && !link_synch(l)) {
-				kfree_skb(skb);
-				return rc;
-			}
-
 		/* Packet can be delivered */
 		l->rcv_nxt++;
 		l->stats.recv_info++;
 		if (unlikely(!tipc_data_input(l, skb)))
-			rc |= tipc_link_input(l, skb);
+			rc = tipc_link_input(l, skb);
 
 		/* Ack at regular intervals */
 		if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN)) {
@@ -1288,7 +1218,7 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
 	} else {
 		/* RESET_MSG or ACTIVATE_MSG */
 		msg_set_max_pkt(hdr, l->advertised_mtu);
-		msg_set_ack(hdr, l->failover_checkpt - 1);
+		msg_set_ack(hdr, l->rcv_nxt - 1);
 		msg_set_next_sent(hdr, 1);
 	}
 	skb = tipc_buf_acquire(msg_size(hdr));
@@ -1296,223 +1226,75 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
 		return;
 	skb_copy_to_linear_data(skb, hdr, msg_size(hdr));
 	skb->priority = TC_PRIO_CONTROL;
-	__skb_queue_head(xmitq, skb);
-}
-
-/* tipc_link_tunnel_xmit(): Tunnel one packet via a link belonging to
- * a different bearer. Owner node is locked.
- */
-static void tipc_link_tunnel_xmit(struct tipc_link *l_ptr,
-				  struct tipc_msg *tunnel_hdr,
-				  struct tipc_msg *msg,
-				  u32 selector)
-{
-	struct tipc_link *tunnel;
-	struct sk_buff *skb;
-	u32 length = msg_size(msg);
-
-	tunnel = node_active_link(l_ptr->owner, selector & 1);
-	if (!tipc_link_is_up(tunnel)) {
-		pr_warn("%stunnel link no longer available\n", link_co_err);
-		return;
-	}
-	msg_set_size(tunnel_hdr, length + INT_H_SIZE);
-	skb = tipc_buf_acquire(length + INT_H_SIZE);
-	if (!skb) {
-		pr_warn("%sunable to send tunnel msg\n", link_co_err);
-		return;
-	}
-	skb_copy_to_linear_data(skb, tunnel_hdr, INT_H_SIZE);
-	skb_copy_to_linear_data_offset(skb, INT_H_SIZE, msg, length);
-	__tipc_link_xmit_skb(tunnel, skb);
+	__skb_queue_tail(xmitq, skb);
 }
 
-
-/* tipc_link_failover_send_queue(): A link has gone down, but a second
- * link is still active. We can do failover. Tunnel the failing link's
- * whole send queue via the remaining link. This way, we don't lose
- * any packets, and sequence order is preserved for subsequent traffic
- * sent over the remaining link. Owner node is locked.
+/* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets
+ * with contents of the link's tranmsit and backlog queues.
  */
-void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
+void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
+			   int mtyp, struct sk_buff_head *xmitq)
 {
-	int msgcount;
-	struct tipc_link *tunnel = node_active_link(l_ptr->owner, 0);
-	struct tipc_msg tunnel_hdr;
-	struct sk_buff *skb;
-	int split_bundles;
+	struct sk_buff *skb, *tnlskb;
+	struct tipc_msg *hdr, tnlhdr;
+	struct sk_buff_head *queue = &l->transmq;
+	struct sk_buff_head tmpxq, tnlq;
+	u16 pktlen, pktcnt, seqno = l->snd_nxt;
 
-	if (!tunnel)
+	if (!tnl)
 		return;
 
-	tipc_msg_init(link_own_addr(l_ptr), &tunnel_hdr, TUNNEL_PROTOCOL,
-		      FAILOVER_MSG, INT_H_SIZE, l_ptr->addr);
+	skb_queue_head_init(&tnlq);
+	skb_queue_head_init(&tmpxq);
 
-	skb_queue_walk(&l_ptr->backlogq, skb) {
-		msg_set_seqno(buf_msg(skb), l_ptr->snd_nxt);
-		l_ptr->snd_nxt = mod(l_ptr->snd_nxt + 1);
-	}
-	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->transmq)) {
-		skb = tipc_buf_acquire(INT_H_SIZE);
-		if (skb) {
-			skb_copy_to_linear_data(skb, &tunnel_hdr, INT_H_SIZE);
-			msg_set_size(&tunnel_hdr, INT_H_SIZE);
-			__tipc_link_xmit_skb(tunnel, skb);
-		} else {
-			pr_warn("%sunable to send changeover msg\n",
-				link_co_err);
-		}
+	/* At least one packet required for safe algorithm => add dummy */
+	skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
+			      BASIC_H_SIZE, 0, l->addr, link_own_addr(l),
+			      0, 0, TIPC_ERR_NO_PORT);
+	if (!skb) {
+		pr_warn("%sunable to create tunnel packet\n", link_co_err);
 		return;
 	}
-
-	split_bundles = (node_active_link(l_ptr->owner, 0) !=
-			 node_active_link(l_ptr->owner, 0));
-
-	skb_queue_walk(&l_ptr->transmq, skb) {
-		struct tipc_msg *msg = buf_msg(skb);
-
-		if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
-			struct tipc_msg *m = msg_get_wrapped(msg);
-			unchar *pos = (unchar *)m;
-
-			msgcount = msg_msgcnt(msg);
-			while (msgcount--) {
-				msg_set_seqno(m, msg_seqno(msg));
-				tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, m,
-						      msg_link_selector(m));
-				pos += align(msg_size(m));
-				m = (struct tipc_msg *)pos;
-			}
-		} else {
-			tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, msg,
-					      msg_link_selector(msg));
-		}
-	}
-}
-
-/* tipc_link_dup_queue_xmit(): A second link has become active. Tunnel a
- * duplicate of the first link's send queue via the new link. This way, we
- * are guaranteed that currently queued packets from a socket are delivered
- * before future traffic from the same socket, even if this is using the
- * new link. The last arriving copy of each duplicate packet is dropped at
- * the receiving end by the regular protocol check, so packet cardinality
- * and sequence order is preserved per sender/receiver socket pair.
- * Owner node is locked.
- */
-void tipc_link_dup_queue_xmit(struct tipc_link *link,
-			      struct tipc_link *tnl)
-{
-	struct sk_buff *skb;
-	struct tipc_msg tnl_hdr;
-	struct sk_buff_head *queue = &link->transmq;
-	int mcnt;
-	u16 seqno;
-
-	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_tail(&tnlq, skb);
+	tipc_link_xmit(l, &tnlq, &tmpxq);
+	__skb_queue_purge(&tmpxq);
+
+	/* Initialize reusable tunnel packet header */
+	tipc_msg_init(link_own_addr(l), &tnlhdr, TUNNEL_PROTOCOL,
+		      mtyp, INT_H_SIZE, l->addr);
+	pktcnt = skb_queue_len(&l->transmq) + skb_queue_len(&l->backlogq);
+	msg_set_msgcnt(&tnlhdr, pktcnt);
+	msg_set_bearer_id(&tnlhdr, l->peer_bearer_id);
+tnl:
+	/* Wrap each packet into a tunnel packet */
 	skb_queue_walk(queue, skb) {
-		struct sk_buff *outskb;
-		struct tipc_msg *msg = buf_msg(skb);
-		u32 len = msg_size(msg);
-
-		msg_set_ack(msg, mod(link->rcv_nxt - 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);
+		hdr = buf_msg(skb);
+		if (queue == &l->backlogq)
+			msg_set_seqno(hdr, seqno++);
+		pktlen = msg_size(hdr);
+		msg_set_size(&tnlhdr, pktlen + INT_H_SIZE);
+		tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE);
+		if (!tnlskb) {
+			pr_warn("%sunable to send packet\n", link_co_err);
 			return;
 		}
-		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;
+		skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE);
+		skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen);
+		__skb_queue_tail(&tnlq, tnlskb);
 	}
-	if (queue == &link->backlogq)
-		return;
-	seqno = link->snd_nxt;
-	skb_queue_walk(&link->backlogq, skb) {
-		msg_set_seqno(buf_msg(skb), seqno);
-		seqno = mod(seqno + 1);
-	}
-	queue = &link->backlogq;
-	goto tunnel_queue;
-}
-
-/*  tipc_link_failover_rcv(): Receive a tunnelled FAILOVER_MSG packet
- *  Owner node is locked.
- */
-static int tipc_link_failover_rcv(struct tipc_link *link,
-				  struct sk_buff **skb)
-{
-	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;
-	int rc = 0;
-
-	if (msg_type(msg) != FAILOVER_MSG) {
-		pr_warn("%sunknown tunnel pkt received\n", link_co_err);
-		goto exit;
+	if (queue != &l->backlogq) {
+		queue = &l->backlogq;
+		goto tnl;
 	}
-	if (bearer_id >= MAX_BEARERS)
-		goto exit;
-
-	if (bearer_id == link->bearer_id)
-		goto exit;
-
-	pl = link->owner->links[bearer_id].link;
-
-	if (link->failover_pkts == FIRST_FAILOVER)
-		link->failover_pkts = msg_msgcnt(msg);
-
-	/* Should we expect an inner packet? */
-	if (!link->failover_pkts)
-		goto exit;
 
-	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;
+	tipc_link_xmit(tnl, &tnlq, xmitq);
 
-	/* 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++;
-		if (!tipc_buf_append(&link->failover_skb, &iskb) &&
-		    !link->failover_skb) {
-			link->exec_mode = TIPC_LINK_BLOCKED;
-			rc |= TIPC_LINK_DOWN_EVT;
-		}
+	if (mtyp == FAILOVER_MSG) {
+		tnl->drop_point = l->rcv_nxt;
+		tnl->failover_reasm_skb = l->reasm_buf;
+		l->reasm_buf = NULL;
+		l->exec_mode = TIPC_LINK_BLOCKED;
 	}
-exit:
-	if (!link->failover_pkts && pl)
-		pl->exec_mode = TIPC_LINK_OPEN;
-	kfree_skb(*skb);
-	*skb = iskb;
-	return rc;
 }
 
 /* tipc_link_proto_rcv(): receive link level protocol message :
@@ -1593,7 +1375,7 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
 
 		/* If NACK, retransmit will now start at right position */
 		if (nacked_gap) {
-			rc |= tipc_link_retransm(l, nacked_gap, xmitq);
+			rc = tipc_link_retransm(l, nacked_gap, xmitq);
 			l->stats.recv_nacks++;
 		}
 		tipc_link_advance_backlog(l, xmitq);

net/tipc/link.h

@@ -164,13 +164,11 @@ struct tipc_link {
 	struct tipc_msg *pmsg;
 	u32 priority;
 	char net_plane;
-	u8 exec_mode;
-	u16 synch_point;
 
-	/* Failover */
-	u16 failover_pkts;
-	u16 failover_checkpt;
-	struct sk_buff *failover_skb;
+	/* Failover/synch */
+	u8 exec_mode;
+	u16 drop_point;
+	struct sk_buff *failover_reasm_skb;
 
 	/* Max packet negotiation */
 	u16 mtu;
@@ -212,8 +210,8 @@ struct tipc_link *tipc_link_create(struct tipc_node *n,
 				   const struct tipc_media_addr *maddr,
 				   struct sk_buff_head *inputq,
 				   struct sk_buff_head *namedq);
-void tipc_link_failover_send_queue(struct tipc_link *l_ptr);
-void tipc_link_dup_queue_xmit(struct tipc_link *l_ptr, struct tipc_link *dest);
+void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
+			   int mtyp, struct sk_buff_head *xmitq);
 void tipc_link_reset_fragments(struct tipc_link *l_ptr);
 int tipc_link_is_up(struct tipc_link *l_ptr);
 int tipc_link_is_active(struct tipc_link *l_ptr);

net/tipc/msg.h

@@ -110,7 +110,6 @@ struct tipc_skb_cb {
 	struct sk_buff *tail;
 	bool validated;
 	bool wakeup_pending;
-	bool bundling;
 	u16 chain_sz;
 	u16 chain_imp;
 };
@@ -559,15 +558,6 @@ static inline void msg_set_node_capabilities(struct tipc_msg *m, u32 n)
 	msg_set_bits(m, 1, 15, 0x1fff, n);
 }
 
-static inline bool msg_dup(struct tipc_msg *m)
-{
-	if (likely(msg_user(m) != TUNNEL_PROTOCOL))
-		return false;
-	if (msg_type(m) != SYNCH_MSG)
-		return false;
-	return true;
-}
-
 /*
  * Word 2
  */
@@ -621,12 +611,12 @@ static inline void msg_set_fragm_no(struct tipc_msg *m, u32 n)
 }
 
 
-static inline u32 msg_next_sent(struct tipc_msg *m)
+static inline u16 msg_next_sent(struct tipc_msg *m)
 {
 	return msg_bits(m, 4, 0, 0xffff);
 }
 
-static inline void msg_set_next_sent(struct tipc_msg *m, u32 n)
+static inline void msg_set_next_sent(struct tipc_msg *m, u16 n)
 {
 	msg_set_bits(m, 4, 0, 0xffff, n);
 }
@@ -727,12 +717,12 @@ static inline char *msg_media_addr(struct tipc_msg *m)
 /*
  * Word 9
  */
-static inline u32 msg_msgcnt(struct tipc_msg *m)
+static inline u16 msg_msgcnt(struct tipc_msg *m)
 {
 	return msg_bits(m, 9, 16, 0xffff);
 }
 
-static inline void msg_set_msgcnt(struct tipc_msg *m, u32 n)
+static inline void msg_set_msgcnt(struct tipc_msg *m, u16 n)
 {
 	msg_set_bits(m, 9, 16, 0xffff, n);
 }
@@ -767,19 +757,19 @@ static inline void msg_set_link_tolerance(struct tipc_msg *m, u32 n)
 	msg_set_bits(m, 9, 0, 0xffff, n);
 }
 
-static inline bool msg_is_traffic(struct tipc_msg *m)
+static inline bool msg_peer_link_is_up(struct tipc_msg *m)
 {
 	if (likely(msg_user(m) != LINK_PROTOCOL))
 		return true;
-	if ((msg_type(m) == RESET_MSG) || (msg_type(m) == ACTIVATE_MSG))
-		return false;
-	return true;
+	if (msg_type(m) == STATE_MSG)
+		return true;
+	return false;
 }
 
-static inline bool msg_peer_is_up(struct tipc_msg *m)
+static inline bool msg_peer_node_is_up(struct tipc_msg *m)
 {
-	if (likely(msg_is_traffic(m)))
-		return false;
+	if (msg_peer_link_is_up(m))
+		return true;
 	return msg_redundant_link(m);
 }
 

net/tipc/node.c

@@ -42,6 +42,31 @@
 #include "bcast.h"
 #include "discover.h"
 
+/* 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);
 static void node_lost_contact(struct tipc_node *n_ptr);
 static void node_established_contact(struct tipc_node *n_ptr);
 static void tipc_node_delete(struct tipc_node *node);
@@ -281,69 +306,75 @@ static void tipc_node_timeout(unsigned long data)
  *
  * Link becomes active (alone or shared) or standby, depending on its priority.
  */
-void tipc_node_link_up(struct tipc_node *n, int bearer_id)
+static void tipc_node_link_up(struct tipc_node *n, int bearer_id,
+			      struct sk_buff_head *xmitq)
 {
 	int *slot0 = &n->active_links[0];
 	int *slot1 = &n->active_links[1];
-	struct tipc_link_entry *links = n->links;
-	struct tipc_link *l = n->links[bearer_id].link;
-
-	/* Leave room for tunnel header when returning 'mtu' to users: */
-	links[bearer_id].mtu = l->mtu - INT_H_SIZE;
+	struct tipc_link *ol = node_active_link(n, 0);
+	struct tipc_link *nl = n->links[bearer_id].link;
 
+	if (n->working_links > 1) {
+		pr_warn("Attempt to establish 3rd link to %x\n", n->addr);
+		return;
+	}
 	n->working_links++;
 	n->action_flags |= TIPC_NOTIFY_LINK_UP;
-	n->link_id = l->peer_bearer_id << 16 | l->bearer_id;
+	n->link_id = nl->peer_bearer_id << 16 | bearer_id;
+
+	/* 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",
-		 l->name, l->net_plane);
+		 nl->name, nl->net_plane);
 
-	/* No active links ? => take both active slots */
-	if (!tipc_node_is_up(n)) {
+	/* First link? => give it both slots */
+	if (!ol) {
 		*slot0 = bearer_id;
 		*slot1 = bearer_id;
+		nl->exec_mode = TIPC_LINK_OPEN;
 		node_established_contact(n);
 		return;
 	}
 
-	/* Lower prio than current active ? => no slot */
-	if (l->priority < links[*slot0].link->priority) {
-		pr_debug("New link <%s> becomes standby\n", l->name);
-		return;
-	}
-	tipc_link_dup_queue_xmit(links[*slot0].link, l);
-
-	/* Same prio as current active ? => take one slot */
-	if (l->priority == links[*slot0].link->priority) {
+	/* Second link => redistribute slots */
+	if (nl->priority > ol->priority) {
+		pr_debug("Old link <%s> becomes standby\n", ol->name);
 		*slot0 = bearer_id;
-		return;
+		*slot1 = bearer_id;
+	} else if (nl->priority == ol->priority) {
+		*slot0 = bearer_id;
+	} else {
+		pr_debug("New link <%s> is standby\n", nl->name);
 	}
 
-	/* Higher prio than current active => take both active slots */
-	pr_debug("Old link <%s> now standby\n", links[*slot0].link->name);
-	*slot0 = bearer_id;
-	*slot1 = bearer_id;
+	/* Prepare synchronization with first link */
+	tipc_link_tnl_prepare(ol, nl, SYNCH_MSG, xmitq);
 }
 
 /**
  * tipc_node_link_down - handle loss of link
  */
-void tipc_node_link_down(struct tipc_node *n, int bearer_id)
+static void tipc_node_link_down(struct tipc_node *n, int bearer_id)
 {
 	int *slot0 = &n->active_links[0];
 	int *slot1 = &n->active_links[1];
+	struct tipc_media_addr *maddr = &n->links[bearer_id].maddr;
 	int i, highest = 0;
-	struct tipc_link *l, *_l;
+	struct tipc_link *l, *_l, *tnl;
+	struct sk_buff_head xmitq;
 
 	l = n->links[bearer_id].link;
 	if (!l || !tipc_link_is_up(l))
 		return;
 
+	__skb_queue_head_init(&xmitq);
+
 	n->working_links--;
 	n->action_flags |= TIPC_NOTIFY_LINK_DOWN;
-	n->link_id = l->peer_bearer_id << 16 | l->bearer_id;
+	n->link_id = l->peer_bearer_id << 16 | bearer_id;
 
 	tipc_bearer_remove_dest(n->net, l->bearer_id, n->addr);
 
@@ -370,13 +401,19 @@ void tipc_node_link_down(struct tipc_node *n, int bearer_id)
 		*slot1 = i;
 	}
 
-	if (tipc_node_is_up(n))
-		tipc_link_failover_send_queue(l);
+	if (!tipc_node_is_up(n)) {
+		tipc_link_reset(l);
+		node_lost_contact(n);
+		return;
+	}
 
+	/* There is still a working link => initiate failover */
+	tnl = node_active_link(n, 0);
+	tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
+	n->sync_point = tnl->rcv_nxt + (U16_MAX / 2 - 1);
+	tipc_link_tnl_prepare(l, tnl, FAILOVER_MSG, &xmitq);
 	tipc_link_reset(l);
-
-	if (!tipc_node_is_up(n))
-		node_lost_contact(n);
+	tipc_bearer_xmit(n->net, tnl->bearer_id, &xmitq, maddr);
 }
 
 bool tipc_node_is_up(struct tipc_node *n)
@@ -652,37 +689,22 @@ illegal_evt:
 	pr_err("Illegal node fsm evt %x in state %x\n", evt, state);
 }
 
-bool tipc_node_filter_skb(struct tipc_node *n, struct tipc_link *l,
-			  struct tipc_msg *hdr)
+bool tipc_node_filter_pkt(struct tipc_node *n, struct tipc_msg *hdr)
 {
 	int state = n->state;
 
 	if (likely(state == SELF_UP_PEER_UP))
 		return true;
 
-	if (state == SELF_DOWN_PEER_DOWN)
-		return true;
-
-	if (state == SELF_UP_PEER_COMING) {
-		/* If not traffic msg, peer may still be ESTABLISHING */
-		if (tipc_link_is_up(l) && msg_is_traffic(hdr))
-			tipc_node_fsm_evt(n, PEER_ESTABL_CONTACT_EVT);
-		return true;
-	}
-
-	if (state == SELF_COMING_PEER_UP)
-		return true;
-
 	if (state == SELF_LEAVING_PEER_DOWN)
 		return false;
 
 	if (state == SELF_DOWN_PEER_LEAVING) {
-		if (msg_peer_is_up(hdr))
+		if (msg_peer_node_is_up(hdr))
 			return false;
-		tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
-		return true;
 	}
-	return false;
+
+	return true;
 }
 
 static void node_established_contact(struct tipc_node *n_ptr)
@@ -727,10 +749,8 @@ static void node_lost_contact(struct tipc_node *n_ptr)
 		if (!l_ptr)
 			continue;
 		l_ptr->exec_mode = TIPC_LINK_OPEN;
-		l_ptr->failover_checkpt = 0;
-		l_ptr->failover_pkts = 0;
-		kfree_skb(l_ptr->failover_skb);
-		l_ptr->failover_skb = NULL;
+		kfree_skb(l_ptr->failover_reasm_skb);
+		l_ptr->failover_reasm_skb = NULL;
 		tipc_link_reset_fragments(l_ptr);
 	}
 	/* Prevent re-contact with node until cleanup is done */
@@ -961,38 +981,111 @@ int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
 	return 0;
 }
 
-/* tipc_node_tnl_init(): handle a received TUNNEL_PROTOCOL packet,
- * in order to control parallel link failover or synchronization
+/**
+ * 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 void tipc_node_tnl_init(struct tipc_node *n, int bearer_id,
-			       struct sk_buff *skb)
+static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
+				  int bearer_id)
 {
-	struct tipc_link *tnl, *pl;
 	struct tipc_msg *hdr = buf_msg(skb);
+	int usr = msg_user(hdr);
+	int mtyp = msg_type(hdr);
 	u16 oseqno = msg_seqno(hdr);
-	int pb_id = msg_bearer_id(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, *pl = NULL;
+	struct sk_buff_head;
+	int i;
 
-	if (pb_id >= MAX_BEARERS)
-		return;
+	l = n->links[bearer_id].link;
+	if (!l)
+		return false;
+	rcv_nxt = l->rcv_nxt;
 
-	tnl = n->links[bearer_id].link;
-	if (!tnl)
-		return;
 
-	/* Ignore if duplicate */
-	if (less(oseqno, tnl->rcv_nxt))
-		return;
+	if (likely((state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL)))
+		return true;
 
-	pl = n->links[pb_id].link;
-	if (!pl)
-		return;
+	/* 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;
+		}
+	}
 
-	if (msg_type(hdr) == FAILOVER_MSG) {
-		if (tipc_link_is_up(pl)) {
-			tipc_node_link_down(n, pb_id);
+	/* 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)) {
+			tipc_node_link_down(n, pl->bearer_id);
 			pl->exec_mode = TIPC_LINK_BLOCKED;
 		}
+		/* 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) && (more(rcv_nxt, n->sync_point))) {
+		tipc_node_fsm_evt(n, NODE_FAILOVER_END_EVT);
+		if (pl)
+			pl->exec_mode = TIPC_LINK_OPEN;
+		return true;
+	}
+
+	/* Initiate or update synch mode if applicable */
+	if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG)) {
+		syncpt = iseqno + exp_pkts - 1;
+		if (n->state == SELF_UP_PEER_UP) {
+			n->sync_point = syncpt;
+			tipc_node_fsm_evt(n, NODE_SYNCH_BEGIN_EVT);
+		}
+		l->exec_mode = TIPC_LINK_TUNNEL;
+		if (less(syncpt, n->sync_point))
+			n->sync_point = syncpt;
 	}
+
+	/* Open tunnel link when parallel link reaches synch point */
+	if ((n->state == NODE_SYNCHING) && (l->exec_mode == TIPC_LINK_TUNNEL)) {
+		if (pl)
+			dlv_nxt = mod(pl->rcv_nxt - skb_queue_len(pl->inputq));
+		if (!pl || more(dlv_nxt, n->sync_point)) {
+			tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
+			l->exec_mode = TIPC_LINK_OPEN;
+			return true;
+		}
+		if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG))
+			return true;
+		if (usr == LINK_PROTOCOL)
+			return true;
+		return false;
+	}
+	return true;
 }
 
 /**
@@ -1008,12 +1101,11 @@ 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_link *l;
-	struct tipc_msg *hdr;
-	struct tipc_media_addr *maddr;
+	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;
-	int usr;
 
 	__skb_queue_head_init(&xmitq);
 
@@ -1022,8 +1114,6 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
 		goto discard;
 
 	/* Handle arrival of a non-unicast link packet */
-	hdr = buf_msg(skb);
-	usr = msg_user(hdr);
 	if (unlikely(msg_non_seq(hdr))) {
 		if (usr ==  LINK_CONFIG)
 			tipc_disc_rcv(net, skb, b);
@@ -1036,42 +1126,41 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
 	n = tipc_node_find(net, msg_prevnode(hdr));
 	if (unlikely(!n))
 		goto discard;
-	tipc_node_lock(n);
+	le = &n->links[bearer_id];
 
-	/* Prepare links for tunneled reception if applicable */
-	if (unlikely(usr == TUNNEL_PROTOCOL))
-		tipc_node_tnl_init(n, bearer_id, skb);
+	tipc_node_lock(n);
 
-	/* Locate link endpoint that should handle packet */
-	l = n->links[bearer_id].link;
-	if (unlikely(!l))
+	/* Is reception permitted at the moment ? */
+	if (!tipc_node_filter_pkt(n, hdr))
 		goto unlock;
 
-	/* Is reception of this packet permitted at the moment ? */
-	if (unlikely(n->state != SELF_UP_PEER_UP))
-		if (!tipc_node_filter_skb(n, l, hdr))
-			goto unlock;
-
-	if (unlikely(usr == LINK_PROTOCOL))
+	if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
 		tipc_bclink_sync_state(n, hdr);
 
 	/* Release acked broadcast messages */
 	if (unlikely(n->bclink.acked != msg_bcast_ack(hdr)))
 		tipc_bclink_acknowledge(n, msg_bcast_ack(hdr));
 
-	/* Check protocol and update link state */
-	rc = tipc_link_rcv(l, skb, &xmitq);
+	/* Check and if necessary update node state */
+	if (likely(tipc_node_check_state(n, skb, bearer_id))) {
+		rc = tipc_link_rcv(le->link, skb, &xmitq);
+		skb = NULL;
+	}
 
 	if (unlikely(rc & TIPC_LINK_UP_EVT))
-		tipc_node_link_up(n, bearer_id);
+		tipc_node_link_up(n, bearer_id, &xmitq);
+
 	if (unlikely(rc & TIPC_LINK_DOWN_EVT))
 		tipc_node_link_down(n, bearer_id);
-	skb = NULL;
 unlock:
 	tipc_node_unlock(n);
-	tipc_sk_rcv(net, &n->links[bearer_id].inputq);
-	maddr = &n->links[bearer_id].maddr;
-	tipc_bearer_xmit(net, bearer_id, &xmitq, maddr);
+
+	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);

net/tipc/node.h

@@ -47,33 +47,7 @@
 
 #define INVALID_BEARER_ID -1
 
-/* 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 = 0xfece,
-	PEER_LOST_CONTACT_EVT   = 0xf1ce,
-	NODE_FAILOVER_BEGIN_EVT = 0xfbe,
-	NODE_FAILOVER_END_EVT   = 0xfee,
-	NODE_SYNCH_BEGIN_EVT    = 0xcbe,
-	NODE_SYNCH_END_EVT      = 0xcee
-};
-
 /* Flags used to take different actions according to flag type
- * TIPC_WAIT_PEER_LINKS_DOWN: wait to see that peer's links are down
- * TIPC_WAIT_OWN_LINKS_DOWN: wait until peer node is declared down
  * TIPC_NOTIFY_NODE_DOWN: notify node is down
  * TIPC_NOTIFY_NODE_UP: notify node is up
  * TIPC_DISTRIBUTE_NAME: publish or withdraw link state name type
@@ -133,6 +107,8 @@ struct tipc_link_entry {
  * @links: array containing references to all links to node
  * @action_flags: bit mask of different types of node actions
  * @bclink: broadcast-related info
+ * @state: connectivity state vs peer node
+ * @sync_point: sequence number where synch/failover is finished
  * @list: links to adjacent nodes in sorted list of cluster's nodes
  * @working_links: number of working links to node (both active and standby)
  * @link_cnt: number of links to node
@@ -156,6 +132,7 @@ struct tipc_node {
 	struct tipc_node_bclink bclink;
 	struct list_head list;
 	int state;
+	u16 sync_point;
 	int link_cnt;
 	u16 working_links;
 	u16 capabilities;
@@ -180,8 +157,6 @@ bool tipc_node_update_dest(struct tipc_node *n, struct tipc_bearer *bearer,
 void tipc_node_delete_links(struct net *net, int bearer_id);
 void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr);
 void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr);
-void tipc_node_link_down(struct tipc_node *n_ptr, int bearer_id);
-void tipc_node_link_up(struct tipc_node *n_ptr, int bearer_id);
 bool tipc_node_is_up(struct tipc_node *n);
 int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 node,
 			   char *linkname, size_t len);