1 files changed, 190 insertions, 101 deletions

diff --git a/net/tipc/node.c b/net/tipc/node.c
index 6b18d73830ca..b0372bb107f6 100644
--- a/net/tipc/node.c
+++ b/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);