diff --git a/net/tipc/link.c b/net/tipc/link.c
index f250102..7a353ff 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -44,6 +44,7 @@
 #include "netlink.h"
 #include "monitor.h"
 #include "trace.h"
+#include "crypto.h"
 
 #include <linux/pkt_sched.h>
 
@@ -163,7 +164,6 @@
 		struct sk_buff *target_bskb;
 	} backlog[5];
 	u16 snd_nxt;
-	u16 window;
 
 	/* Reception */
 	u16 rcv_nxt;
@@ -174,6 +174,12 @@
 
 	/* Congestion handling */
 	struct sk_buff_head wakeupq;
+	u16 window;
+	u16 min_win;
+	u16 ssthresh;
+	u16 max_win;
+	u16 cong_acks;
+	u16 checkpoint;
 
 	/* Fragmentation/reassembly */
 	struct sk_buff *reasm_buf;
@@ -182,6 +188,8 @@
 	/* Broadcast */
 	u16 ackers;
 	u16 acked;
+	u16 last_gap;
+	struct tipc_gap_ack_blks *last_ga;
 	struct tipc_link *bc_rcvlink;
 	struct tipc_link *bc_sndlink;
 	u8 nack_state;
@@ -208,11 +216,6 @@
 #define TIPC_BC_RETR_LIM  (jiffies + msecs_to_jiffies(10))
 #define TIPC_UC_RETR_TIME (jiffies + msecs_to_jiffies(1))
 
-/*
- * Interval between NACKs when packets arrive out of order
- */
-#define TIPC_NACK_INTV (TIPC_MIN_LINK_WIN * 2)
-
 /* Link FSM states:
  */
 enum {
@@ -243,12 +246,16 @@
 				    struct sk_buff_head *xmitq);
 static void tipc_link_build_bc_init_msg(struct tipc_link *l,
 					struct sk_buff_head *xmitq);
-static bool tipc_link_release_pkts(struct tipc_link *l, u16 to);
-static u16 tipc_build_gap_ack_blks(struct tipc_link *l, void *data);
-static int tipc_link_advance_transmq(struct tipc_link *l, u16 acked, u16 gap,
+static u8 __tipc_build_gap_ack_blks(struct tipc_gap_ack_blks *ga,
+				    struct tipc_link *l, u8 start_index);
+static u16 tipc_build_gap_ack_blks(struct tipc_link *l, struct tipc_msg *hdr);
+static int tipc_link_advance_transmq(struct tipc_link *l, struct tipc_link *r,
+				     u16 acked, u16 gap,
 				     struct tipc_gap_ack_blks *ga,
-				     struct sk_buff_head *xmitq);
-
+				     struct sk_buff_head *xmitq,
+				     bool *retransmitted, int *rc);
+static void tipc_link_update_cwin(struct tipc_link *l, int released,
+				  bool retransmitted);
 /*
  *  Simple non-static link routines (i.e. referenced outside this file)
  */
@@ -307,9 +314,14 @@
 	return l->peer_bearer_id << 16 | l->bearer_id;
 }
 
-int tipc_link_window(struct tipc_link *l)
+int tipc_link_min_win(struct tipc_link *l)
 {
-	return l->window;
+	return l->min_win;
+}
+
+int tipc_link_max_win(struct tipc_link *l)
+{
+	return l->max_win;
 }
 
 int tipc_link_prio(struct tipc_link *l)
@@ -358,7 +370,7 @@
 	snd_l->ackers--;
 	rcv_l->bc_peer_is_up = true;
 	rcv_l->state = LINK_ESTABLISHED;
-	tipc_link_bc_ack_rcv(rcv_l, ack, xmitq);
+	tipc_link_bc_ack_rcv(rcv_l, ack, 0, NULL, xmitq, NULL);
 	trace_tipc_link_reset(rcv_l, TIPC_DUMP_ALL, "bclink removed!");
 	tipc_link_reset(rcv_l);
 	rcv_l->state = LINK_RESET;
@@ -397,6 +409,15 @@
 	return l->mtu;
 }
 
+int tipc_link_mss(struct tipc_link *l)
+{
+#ifdef CONFIG_TIPC_CRYPTO
+	return l->mtu - INT_H_SIZE - EMSG_OVERHEAD;
+#else
+	return l->mtu - INT_H_SIZE;
+#endif
+}
+
 u16 tipc_link_rcv_nxt(struct tipc_link *l)
 {
 	return l->rcv_nxt;
@@ -419,14 +440,15 @@
 
 /**
  * tipc_link_create - create a new link
- * @n: pointer to associated node
+ * @net: pointer to associated network namespace
  * @if_name: associated interface name
  * @bearer_id: id (index) of associated bearer
  * @tolerance: link tolerance to be used by link
  * @net_plane: network plane (A,B,c..) this link belongs to
  * @mtu: mtu to be advertised by link
  * @priority: priority to be used by link
- * @window: send window to be used by link
+ * @min_win: minimal send window to be used by link
+ * @max_win: maximal send window to be used by link
  * @session: session to be used by link
  * @ownnode: identity of own node
  * @peer: node id of peer node
@@ -441,7 +463,7 @@
  */
 bool tipc_link_create(struct net *net, char *if_name, int bearer_id,
 		      int tolerance, char net_plane, u32 mtu, int priority,
-		      int window, u32 session, u32 self,
+		      u32 min_win, u32 max_win, u32 session, u32 self,
 		      u32 peer, u8 *peer_id, u16 peer_caps,
 		      struct tipc_link *bc_sndlink,
 		      struct tipc_link *bc_rcvlink,
@@ -485,7 +507,7 @@
 	l->advertised_mtu = mtu;
 	l->mtu = mtu;
 	l->priority = priority;
-	tipc_link_set_queue_limits(l, window);
+	tipc_link_set_queue_limits(l, min_win, max_win);
 	l->ackers = 1;
 	l->bc_sndlink = bc_sndlink;
 	l->bc_rcvlink = bc_rcvlink;
@@ -503,17 +525,18 @@
 
 /**
  * tipc_link_bc_create - create new link to be used for broadcast
- * @n: pointer to associated node
+ * @net: pointer to associated network namespace
  * @mtu: mtu to be used initially if no peers
- * @window: send window to be used
+ * @min_win: minimal send window to be used by link
+ * @max_win: maximal send window to be used by link
  * @inputq: queue to put messages ready for delivery
  * @namedq: queue to put binding table update messages ready for delivery
  * @link: return value, pointer to put the created link
  *
  * Returns true if link was created, otherwise false
  */
-bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer,
-			 int mtu, int window, u16 peer_caps,
+bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer, u8 *peer_id,
+			 int mtu, u32 min_win, u32 max_win, u16 peer_caps,
 			 struct sk_buff_head *inputq,
 			 struct sk_buff_head *namedq,
 			 struct tipc_link *bc_sndlink,
@@ -521,13 +544,24 @@
 {
 	struct tipc_link *l;
 
-	if (!tipc_link_create(net, "", MAX_BEARERS, 0, 'Z', mtu, 0, window,
-			      0, ownnode, peer, NULL, peer_caps, bc_sndlink,
-			      NULL, inputq, namedq, link))
+	if (!tipc_link_create(net, "", MAX_BEARERS, 0, 'Z', mtu, 0, min_win,
+			      max_win, 0, ownnode, peer, NULL, peer_caps,
+			      bc_sndlink, NULL, inputq, namedq, link))
 		return false;
 
 	l = *link;
-	strcpy(l->name, tipc_bclink_name);
+	if (peer_id) {
+		char peer_str[NODE_ID_STR_LEN] = {0,};
+
+		tipc_nodeid2string(peer_str, peer_id);
+		if (strlen(peer_str) > 16)
+			sprintf(peer_str, "%x", peer);
+		/* Broadcast receiver link name: "broadcast-link:<peer>" */
+		snprintf(l->name, sizeof(l->name), "%s:%s", tipc_bclink_name,
+			 peer_str);
+	} else {
+		strcpy(l->name, tipc_bclink_name);
+	}
 	trace_tipc_link_reset(l, TIPC_DUMP_ALL, "bclink created!");
 	tipc_link_reset(l);
 	l->state = LINK_RESET;
@@ -540,7 +574,7 @@
 
 	/* Disable replicast if even a single peer doesn't support it */
 	if (link_is_bc_rcvlink(l) && !(peer_caps & TIPC_BCAST_RCAST))
-		tipc_bcast_disable_rcast(net);
+		tipc_bcast_toggle_rcast(net, false);
 
 	return true;
 }
@@ -789,11 +823,16 @@
 		state |= l->bc_rcvlink->rcv_unacked;
 		state |= l->rcv_unacked;
 		state |= !skb_queue_empty(&l->transmq);
-		state |= !skb_queue_empty(&l->deferdq);
 		probe = mstate->probing;
 		probe |= l->silent_intv_cnt;
 		if (probe || mstate->monitoring)
 			l->silent_intv_cnt++;
+		probe |= !skb_queue_empty(&l->deferdq);
+		if (l->snd_nxt == l->checkpoint) {
+			tipc_link_update_cwin(l, 0, 0);
+			probe = true;
+		}
+		l->checkpoint = l->snd_nxt;
 		break;
 	case LINK_RESET:
 		setup = l->rst_cnt++ <= 4;
@@ -878,6 +917,21 @@
 
 }
 
+/**
+ * tipc_link_set_skb_retransmit_time - set the time at which retransmission of
+ *                                     the given skb should be next attempted
+ * @skb: skb to set a future retransmission time for
+ * @l: link the skb will be transmitted on
+ */
+static void tipc_link_set_skb_retransmit_time(struct sk_buff *skb,
+					      struct tipc_link *l)
+{
+	if (link_is_bc_sndlink(l))
+		TIPC_SKB_CB(skb)->nxt_retr = TIPC_BC_RETR_LIM;
+	else
+		TIPC_SKB_CB(skb)->nxt_retr = TIPC_UC_RETR_TIME;
+}
+
 void tipc_link_reset(struct tipc_link *l)
 {
 	struct sk_buff_head list;
@@ -919,6 +973,9 @@
 	l->snd_nxt_state = 1;
 	l->rcv_nxt_state = 1;
 	l->acked = 0;
+	l->last_gap = 0;
+	kfree(l->last_ga);
+	l->last_ga = NULL;
 	l->silent_intv_cnt = 0;
 	l->rst_cnt = 0;
 	l->bc_peer_is_up = false;
@@ -928,7 +985,7 @@
 
 /**
  * tipc_link_xmit(): enqueue buffer list according to queue situation
- * @link: link to use
+ * @l: link to use
  * @list: chain of buffers containing message
  * @xmitq: returned list of packets to be sent by caller
  *
@@ -939,16 +996,18 @@
 int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
 		   struct sk_buff_head *xmitq)
 {
-	unsigned int maxwin = l->window;
-	unsigned int mtu = l->mtu;
+	struct sk_buff_head *backlogq = &l->backlogq;
+	struct sk_buff_head *transmq = &l->transmq;
+	struct sk_buff *skb, *_skb;
+	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
 	u16 ack = l->rcv_nxt - 1;
 	u16 seqno = l->snd_nxt;
-	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
-	struct sk_buff_head *transmq = &l->transmq;
-	struct sk_buff_head *backlogq = &l->backlogq;
-	struct sk_buff *skb, *_skb, **tskb;
 	int pkt_cnt = skb_queue_len(list);
+	unsigned int mss = tipc_link_mss(l);
+	unsigned int cwin = l->window;
+	unsigned int mtu = l->mtu;
 	struct tipc_msg *hdr;
+	bool new_bundle;
 	int rc = 0;
 	int imp;
 
@@ -980,24 +1039,20 @@
 	}
 
 	/* Prepare each packet for sending, and add to relevant queue: */
-	while (skb_queue_len(list)) {
-		skb = skb_peek(list);
-		hdr = buf_msg(skb);
-		msg_set_seqno(hdr, seqno);
-		msg_set_ack(hdr, ack);
-		msg_set_bcast_ack(hdr, bc_ack);
-
-		if (likely(skb_queue_len(transmq) < maxwin)) {
+	while ((skb = __skb_dequeue(list))) {
+		if (likely(skb_queue_len(transmq) < cwin)) {
+			hdr = buf_msg(skb);
+			msg_set_seqno(hdr, seqno);
+			msg_set_ack(hdr, ack);
+			msg_set_bcast_ack(hdr, bc_ack);
 			_skb = skb_clone(skb, GFP_ATOMIC);
 			if (!_skb) {
+				kfree_skb(skb);
 				__skb_queue_purge(list);
 				return -ENOBUFS;
 			}
-			__skb_dequeue(list);
 			__skb_queue_tail(transmq, skb);
-			/* next retransmit attempt */
-			if (link_is_bc_sndlink(l))
-				TIPC_SKB_CB(skb)->nxt_retr = TIPC_BC_RETR_LIM;
+			tipc_link_set_skb_retransmit_time(skb, l);
 			__skb_queue_tail(xmitq, _skb);
 			TIPC_SKB_CB(skb)->ackers = l->ackers;
 			l->rcv_unacked = 0;
@@ -1005,39 +1060,86 @@
 			seqno++;
 			continue;
 		}
-		tskb = &l->backlog[imp].target_bskb;
-		if (tipc_msg_bundle(*tskb, hdr, mtu)) {
-			kfree_skb(__skb_dequeue(list));
-			l->stats.sent_bundled++;
-			continue;
-		}
-		if (tipc_msg_make_bundle(tskb, hdr, mtu, l->addr)) {
-			kfree_skb(__skb_dequeue(list));
-			__skb_queue_tail(backlogq, *tskb);
-			l->backlog[imp].len++;
-			l->stats.sent_bundled++;
-			l->stats.sent_bundles++;
+		if (tipc_msg_try_bundle(l->backlog[imp].target_bskb, &skb,
+					mss, l->addr, &new_bundle)) {
+			if (skb) {
+				/* Keep a ref. to the skb for next try */
+				l->backlog[imp].target_bskb = skb;
+				l->backlog[imp].len++;
+				__skb_queue_tail(backlogq, skb);
+			} else {
+				if (new_bundle) {
+					l->stats.sent_bundles++;
+					l->stats.sent_bundled++;
+				}
+				l->stats.sent_bundled++;
+			}
 			continue;
 		}
 		l->backlog[imp].target_bskb = NULL;
-		l->backlog[imp].len += skb_queue_len(list);
+		l->backlog[imp].len += (1 + skb_queue_len(list));
+		__skb_queue_tail(backlogq, skb);
 		skb_queue_splice_tail_init(list, backlogq);
 	}
 	l->snd_nxt = seqno;
 	return rc;
 }
 
+static void tipc_link_update_cwin(struct tipc_link *l, int released,
+				  bool retransmitted)
+{
+	int bklog_len = skb_queue_len(&l->backlogq);
+	struct sk_buff_head *txq = &l->transmq;
+	int txq_len = skb_queue_len(txq);
+	u16 cwin = l->window;
+
+	/* Enter fast recovery */
+	if (unlikely(retransmitted)) {
+		l->ssthresh = max_t(u16, l->window / 2, 300);
+		l->window = min_t(u16, l->ssthresh, l->window);
+		return;
+	}
+	/* Enter slow start */
+	if (unlikely(!released)) {
+		l->ssthresh = max_t(u16, l->window / 2, 300);
+		l->window = l->min_win;
+		return;
+	}
+	/* Don't increase window if no pressure on the transmit queue */
+	if (txq_len + bklog_len < cwin)
+		return;
+
+	/* Don't increase window if there are holes the transmit queue */
+	if (txq_len && l->snd_nxt - buf_seqno(skb_peek(txq)) != txq_len)
+		return;
+
+	l->cong_acks += released;
+
+	/* Slow start  */
+	if (cwin <= l->ssthresh) {
+		l->window = min_t(u16, cwin + released, l->max_win);
+		return;
+	}
+	/* Congestion avoidance */
+	if (l->cong_acks < cwin)
+		return;
+	l->window = min_t(u16, ++cwin, l->max_win);
+	l->cong_acks = 0;
+}
+
 static void tipc_link_advance_backlog(struct tipc_link *l,
 				      struct sk_buff_head *xmitq)
 {
-	struct sk_buff *skb, *_skb;
-	struct tipc_msg *hdr;
-	u16 seqno = l->snd_nxt;
-	u16 ack = l->rcv_nxt - 1;
 	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
+	struct sk_buff_head *txq = &l->transmq;
+	struct sk_buff *skb, *_skb;
+	u16 ack = l->rcv_nxt - 1;
+	u16 seqno = l->snd_nxt;
+	struct tipc_msg *hdr;
+	u16 cwin = l->window;
 	u32 imp;
 
-	while (skb_queue_len(&l->transmq) < l->window) {
+	while (skb_queue_len(txq) < cwin) {
 		skb = skb_peek(&l->backlogq);
 		if (!skb)
 			break;
@@ -1051,9 +1153,7 @@
 		if (unlikely(skb == l->backlog[imp].target_bskb))
 			l->backlog[imp].target_bskb = NULL;
 		__skb_queue_tail(&l->transmq, skb);
-		/* next retransmit attempt */
-		if (link_is_bc_sndlink(l))
-			TIPC_SKB_CB(skb)->nxt_retr = TIPC_BC_RETR_LIM;
+		tipc_link_set_skb_retransmit_time(skb, l);
 
 		__skb_queue_tail(xmitq, _skb);
 		TIPC_SKB_CB(skb)->ackers = l->ackers;
@@ -1112,67 +1212,14 @@
 
 	if (link_is_bc_sndlink(l)) {
 		r->state = LINK_RESET;
-		*rc = TIPC_LINK_DOWN_EVT;
+		*rc |= TIPC_LINK_DOWN_EVT;
 	} else {
-		*rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
+		*rc |= tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
 	}
 
 	return true;
 }
 
-/* tipc_link_bc_retrans() - retransmit zero or more packets
- * @l: the link to transmit on
- * @r: the receiving link ordering the retransmit. Same as l if unicast
- * @from: retransmit from (inclusive) this sequence number
- * @to: retransmit to (inclusive) this sequence number
- * xmitq: queue for accumulating the retransmitted packets
- */
-static int tipc_link_bc_retrans(struct tipc_link *l, struct tipc_link *r,
-				u16 from, u16 to, struct sk_buff_head *xmitq)
-{
-	struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
-	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
-	u16 ack = l->rcv_nxt - 1;
-	struct tipc_msg *hdr;
-	int rc = 0;
-
-	if (!skb)
-		return 0;
-	if (less(to, from))
-		return 0;
-
-	trace_tipc_link_retrans(r, from, to, &l->transmq);
-
-	if (link_retransmit_failure(l, r, &rc))
-		return rc;
-
-	skb_queue_walk(&l->transmq, skb) {
-		hdr = buf_msg(skb);
-		if (less(msg_seqno(hdr), from))
-			continue;
-		if (more(msg_seqno(hdr), to))
-			break;
-
-		if (time_before(jiffies, TIPC_SKB_CB(skb)->nxt_retr))
-			continue;
-		TIPC_SKB_CB(skb)->nxt_retr = TIPC_BC_RETR_LIM;
-		_skb = __pskb_copy(skb, LL_MAX_HEADER + MIN_H_SIZE, GFP_ATOMIC);
-		if (!_skb)
-			return 0;
-		hdr = buf_msg(_skb);
-		msg_set_ack(hdr, ack);
-		msg_set_bcast_ack(hdr, bc_ack);
-		_skb->priority = TC_PRIO_CONTROL;
-		__skb_queue_tail(xmitq, _skb);
-		l->stats.retransmitted++;
-
-		/* Increase actual retrans counter & mark first time */
-		if (!TIPC_SKB_CB(skb)->retr_cnt++)
-			TIPC_SKB_CB(skb)->retr_stamp = jiffies;
-	}
-	return 0;
-}
-
 /* tipc_data_input - deliver data and name distr msgs to upper layer
  *
  * Consumes buffer if message is of right type
@@ -1193,7 +1240,7 @@
 			skb_queue_tail(mc_inputq, skb);
 			return true;
 		}
-		/* fall through */
+		fallthrough;
 	case CONN_MANAGER:
 		skb_queue_tail(inputq, skb);
 		return true;
@@ -1209,6 +1256,14 @@
 	case MSG_FRAGMENTER:
 	case BCAST_PROTOCOL:
 		return false;
+#ifdef CONFIG_TIPC_CRYPTO
+	case MSG_CRYPTO:
+		if (TIPC_SKB_CB(skb)->decrypted) {
+			tipc_crypto_msg_rcv(l->net, skb);
+			return true;
+		}
+		fallthrough;
+#endif
 	default:
 		pr_warn("Dropping received illegal msg type\n");
 		kfree_skb(skb);
@@ -1330,46 +1385,68 @@
 	return rc;
 }
 
-static bool tipc_link_release_pkts(struct tipc_link *l, u16 acked)
+/**
+ * tipc_get_gap_ack_blks - get Gap ACK blocks from PROTOCOL/STATE_MSG
+ * @ga: returned pointer to the Gap ACK blocks if any
+ * @l: the tipc link
+ * @hdr: the PROTOCOL/STATE_MSG header
+ * @uc: desired Gap ACK blocks type, i.e. unicast (= 1) or broadcast (= 0)
+ *
+ * Return: the total Gap ACK blocks size
+ */
+u16 tipc_get_gap_ack_blks(struct tipc_gap_ack_blks **ga, struct tipc_link *l,
+			  struct tipc_msg *hdr, bool uc)
 {
-	bool released = false;
-	struct sk_buff *skb, *tmp;
+	struct tipc_gap_ack_blks *p;
+	u16 sz = 0;
 
-	skb_queue_walk_safe(&l->transmq, skb, tmp) {
-		if (more(buf_seqno(skb), acked))
-			break;
-		__skb_unlink(skb, &l->transmq);
-		kfree_skb(skb);
-		released = true;
+	/* Does peer support the Gap ACK blocks feature? */
+	if (l->peer_caps & TIPC_GAP_ACK_BLOCK) {
+		p = (struct tipc_gap_ack_blks *)msg_data(hdr);
+		sz = ntohs(p->len);
+		/* Sanity check */
+		if (sz == struct_size(p, gacks, p->ugack_cnt + p->bgack_cnt)) {
+			/* Good, check if the desired type exists */
+			if ((uc && p->ugack_cnt) || (!uc && p->bgack_cnt))
+				goto ok;
+		/* Backward compatible: peer might not support bc, but uc? */
+		} else if (uc && sz == struct_size(p, gacks, p->ugack_cnt)) {
+			if (p->ugack_cnt) {
+				p->bgack_cnt = 0;
+				goto ok;
+			}
+		}
 	}
-	return released;
+	/* Other cases: ignore! */
+	p = NULL;
+
+ok:
+	*ga = p;
+	return sz;
 }
 
-/* tipc_build_gap_ack_blks - build Gap ACK blocks
- * @l: tipc link that data have come with gaps in sequence if any
- * @data: data buffer to store the Gap ACK blocks after built
- *
- * returns the actual allocated memory size
- */
-static u16 tipc_build_gap_ack_blks(struct tipc_link *l, void *data)
+static u8 __tipc_build_gap_ack_blks(struct tipc_gap_ack_blks *ga,
+				    struct tipc_link *l, u8 start_index)
 {
+	struct tipc_gap_ack *gacks = &ga->gacks[start_index];
 	struct sk_buff *skb = skb_peek(&l->deferdq);
-	struct tipc_gap_ack_blks *ga = data;
-	u16 len, expect, seqno = 0;
+	u16 expect, seqno = 0;
 	u8 n = 0;
 
 	if (!skb)
-		goto exit;
+		return 0;
 
 	expect = buf_seqno(skb);
 	skb_queue_walk(&l->deferdq, skb) {
 		seqno = buf_seqno(skb);
 		if (unlikely(more(seqno, expect))) {
-			ga->gacks[n].ack = htons(expect - 1);
-			ga->gacks[n].gap = htons(seqno - expect);
-			if (++n >= MAX_GAP_ACK_BLKS) {
-				pr_info_ratelimited("Too few Gap ACK blocks!\n");
-				goto exit;
+			gacks[n].ack = htons(expect - 1);
+			gacks[n].gap = htons(seqno - expect);
+			if (++n >= MAX_GAP_ACK_BLKS / 2) {
+				pr_info_ratelimited("Gacks on %s: %d, ql: %d!\n",
+						    l->name, n,
+						    skb_queue_len(&l->deferdq));
+				return n;
 			}
 		} else if (unlikely(less(seqno, expect))) {
 			pr_warn("Unexpected skb in deferdq!\n");
@@ -1379,14 +1456,44 @@
 	}
 
 	/* last block */
-	ga->gacks[n].ack = htons(seqno);
-	ga->gacks[n].gap = 0;
+	gacks[n].ack = htons(seqno);
+	gacks[n].gap = 0;
 	n++;
+	return n;
+}
 
-exit:
-	len = tipc_gap_ack_blks_sz(n);
+/* tipc_build_gap_ack_blks - build Gap ACK blocks
+ * @l: tipc unicast link
+ * @hdr: the tipc message buffer to store the Gap ACK blocks after built
+ *
+ * The function builds Gap ACK blocks for both the unicast & broadcast receiver
+ * links of a certain peer, the buffer after built has the network data format
+ * as found at the struct tipc_gap_ack_blks definition.
+ *
+ * returns the actual allocated memory size
+ */
+static u16 tipc_build_gap_ack_blks(struct tipc_link *l, struct tipc_msg *hdr)
+{
+	struct tipc_link *bcl = l->bc_rcvlink;
+	struct tipc_gap_ack_blks *ga;
+	u16 len;
+
+	ga = (struct tipc_gap_ack_blks *)msg_data(hdr);
+
+	/* Start with broadcast link first */
+	tipc_bcast_lock(bcl->net);
+	msg_set_bcast_ack(hdr, bcl->rcv_nxt - 1);
+	msg_set_bc_gap(hdr, link_bc_rcv_gap(bcl));
+	ga->bgack_cnt = __tipc_build_gap_ack_blks(ga, bcl, 0);
+	tipc_bcast_unlock(bcl->net);
+
+	/* Now for unicast link, but an explicit NACK only (???) */
+	ga->ugack_cnt = (msg_seq_gap(hdr)) ?
+			__tipc_build_gap_ack_blks(ga, l, ga->bgack_cnt) : 0;
+
+	/* Total len */
+	len = struct_size(ga, gacks, ga->bgack_cnt + ga->ugack_cnt);
 	ga->len = htons(len);
-	ga->gack_cnt = n;
 	return len;
 }
 
@@ -1394,46 +1501,111 @@
  *			       acked packets, also doing retransmissions if
  *			       gaps found
  * @l: tipc link with transmq queue to be advanced
+ * @r: tipc link "receiver" i.e. in case of broadcast (= "l" if unicast)
  * @acked: seqno of last packet acked by peer without any gaps before
  * @gap: # of gap packets
  * @ga: buffer pointer to Gap ACK blocks from peer
  * @xmitq: queue for accumulating the retransmitted packets if any
+ * @retransmitted: returned boolean value if a retransmission is really issued
+ * @rc: returned code e.g. TIPC_LINK_DOWN_EVT if a repeated retransmit failures
+ *      happens (- unlikely case)
  *
- * In case of a repeated retransmit failures, the call will return shortly
- * with a returned code (e.g. TIPC_LINK_DOWN_EVT)
+ * Return: the number of packets released from the link transmq
  */
-static int tipc_link_advance_transmq(struct tipc_link *l, u16 acked, u16 gap,
+static int tipc_link_advance_transmq(struct tipc_link *l, struct tipc_link *r,
+				     u16 acked, u16 gap,
 				     struct tipc_gap_ack_blks *ga,
-				     struct sk_buff_head *xmitq)
+				     struct sk_buff_head *xmitq,
+				     bool *retransmitted, int *rc)
 {
+	struct tipc_gap_ack_blks *last_ga = r->last_ga, *this_ga = NULL;
+	struct tipc_gap_ack *gacks = NULL;
 	struct sk_buff *skb, *_skb, *tmp;
 	struct tipc_msg *hdr;
+	u32 qlen = skb_queue_len(&l->transmq);
+	u16 nacked = acked, ngap = gap, gack_cnt = 0;
 	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
 	u16 ack = l->rcv_nxt - 1;
-	bool passed = false;
 	u16 seqno, n = 0;
-	int rc = 0;
+	u16 end = r->acked, start = end, offset = r->last_gap;
+	u16 si = (last_ga) ? last_ga->start_index : 0;
+	bool is_uc = !link_is_bc_sndlink(l);
+	bool bc_has_acked = false;
 
+	trace_tipc_link_retrans(r, acked + 1, acked + gap, &l->transmq);
+
+	/* Determine Gap ACK blocks if any for the particular link */
+	if (ga && is_uc) {
+		/* Get the Gap ACKs, uc part */
+		gack_cnt = ga->ugack_cnt;
+		gacks = &ga->gacks[ga->bgack_cnt];
+	} else if (ga) {
+		/* Copy the Gap ACKs, bc part, for later renewal if needed */
+		this_ga = kmemdup(ga, struct_size(ga, gacks, ga->bgack_cnt),
+				  GFP_ATOMIC);
+		if (likely(this_ga)) {
+			this_ga->start_index = 0;
+			/* Start with the bc Gap ACKs */
+			gack_cnt = this_ga->bgack_cnt;
+			gacks = &this_ga->gacks[0];
+		} else {
+			/* Hmm, we can get in trouble..., simply ignore it */
+			pr_warn_ratelimited("Ignoring bc Gap ACKs, no memory\n");
+		}
+	}
+
+	/* Advance the link transmq */
 	skb_queue_walk_safe(&l->transmq, skb, tmp) {
 		seqno = buf_seqno(skb);
 
 next_gap_ack:
-		if (less_eq(seqno, acked)) {
+		if (less_eq(seqno, nacked)) {
+			if (is_uc)
+				goto release;
+			/* Skip packets peer has already acked */
+			if (!more(seqno, r->acked))
+				continue;
+			/* Get the next of last Gap ACK blocks */
+			while (more(seqno, end)) {
+				if (!last_ga || si >= last_ga->bgack_cnt)
+					break;
+				start = end + offset + 1;
+				end = ntohs(last_ga->gacks[si].ack);
+				offset = ntohs(last_ga->gacks[si].gap);
+				si++;
+				WARN_ONCE(more(start, end) ||
+					  (!offset &&
+					   si < last_ga->bgack_cnt) ||
+					  si > MAX_GAP_ACK_BLKS,
+					  "Corrupted Gap ACK: %d %d %d %d %d\n",
+					  start, end, offset, si,
+					  last_ga->bgack_cnt);
+			}
+			/* Check against the last Gap ACK block */
+			if (in_range(seqno, start, end))
+				continue;
+			/* Update/release the packet peer is acking */
+			bc_has_acked = true;
+			if (--TIPC_SKB_CB(skb)->ackers)
+				continue;
+release:
 			/* release skb */
 			__skb_unlink(skb, &l->transmq);
 			kfree_skb(skb);
-		} else if (less_eq(seqno, acked + gap)) {
-			/* First, check if repeated retrans failures occurs? */
-			if (!passed && link_retransmit_failure(l, l, &rc))
-				return rc;
-			passed = true;
-
+		} else if (less_eq(seqno, nacked + ngap)) {
+			/* First gap: check if repeated retrans failures? */
+			if (unlikely(seqno == acked + 1 &&
+				     link_retransmit_failure(l, r, rc))) {
+				/* Ignore this bc Gap ACKs if any */
+				kfree(this_ga);
+				this_ga = NULL;
+				break;
+			}
 			/* retransmit skb if unrestricted*/
 			if (time_before(jiffies, TIPC_SKB_CB(skb)->nxt_retr))
 				continue;
-			TIPC_SKB_CB(skb)->nxt_retr = TIPC_UC_RETR_TIME;
-			_skb = __pskb_copy(skb, LL_MAX_HEADER + MIN_H_SIZE,
-					   GFP_ATOMIC);
+			tipc_link_set_skb_retransmit_time(skb, l);
+			_skb = pskb_copy(skb, GFP_ATOMIC);
 			if (!_skb)
 				continue;
 			hdr = buf_msg(_skb);
@@ -1442,22 +1614,53 @@
 			_skb->priority = TC_PRIO_CONTROL;
 			__skb_queue_tail(xmitq, _skb);
 			l->stats.retransmitted++;
-
+			if (!is_uc)
+				r->stats.retransmitted++;
+			*retransmitted = true;
 			/* Increase actual retrans counter & mark first time */
 			if (!TIPC_SKB_CB(skb)->retr_cnt++)
 				TIPC_SKB_CB(skb)->retr_stamp = jiffies;
 		} else {
 			/* retry with Gap ACK blocks if any */
-			if (!ga || n >= ga->gack_cnt)
+			if (n >= gack_cnt)
 				break;
-			acked = ntohs(ga->gacks[n].ack);
-			gap = ntohs(ga->gacks[n].gap);
+			nacked = ntohs(gacks[n].ack);
+			ngap = ntohs(gacks[n].gap);
 			n++;
 			goto next_gap_ack;
 		}
 	}
 
-	return 0;
+	/* Renew last Gap ACK blocks for bc if needed */
+	if (bc_has_acked) {
+		if (this_ga) {
+			kfree(last_ga);
+			r->last_ga = this_ga;
+			r->last_gap = gap;
+		} else if (last_ga) {
+			if (less(acked, start)) {
+				si--;
+				offset = start - acked - 1;
+			} else if (less(acked, end)) {
+				acked = end;
+			}
+			if (si < last_ga->bgack_cnt) {
+				last_ga->start_index = si;
+				r->last_gap = offset;
+			} else {
+				kfree(last_ga);
+				r->last_ga = NULL;
+				r->last_gap = 0;
+			}
+		} else {
+			r->last_gap = 0;
+		}
+		r->acked = acked;
+	} else {
+		kfree(this_ga);
+	}
+
+	return qlen - skb_queue_len(&l->transmq);
 }
 
 /* tipc_link_build_state_msg: prepare link state message for transmission
@@ -1480,7 +1683,6 @@
 		l->snd_nxt = l->rcv_nxt;
 		return TIPC_LINK_SND_STATE;
 	}
-
 	/* Unicast ACK */
 	l->rcv_unacked = 0;
 	l->stats.sent_acks++;
@@ -1514,7 +1716,8 @@
 				    struct sk_buff_head *xmitq)
 {
 	u32 def_cnt = ++l->stats.deferred_recv;
-	u32 defq_len = skb_queue_len(&l->deferdq);
+	struct sk_buff_head *dfq = &l->deferdq;
+	u32 defq_len = skb_queue_len(dfq);
 	int match1, match2;
 
 	if (link_is_bc_rcvlink(l)) {
@@ -1525,8 +1728,12 @@
 		return 0;
 	}
 
-	if (defq_len >= 3 && !((defq_len - 3) % 16))
-		tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, 0, xmitq);
+	if (defq_len >= 3 && !((defq_len - 3) % 16)) {
+		u16 rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt;
+
+		tipc_link_build_proto_msg(l, STATE_MSG, 0, 0,
+					  rcvgap, 0, 0, xmitq);
+	}
 	return 0;
 }
 
@@ -1541,6 +1748,7 @@
 	struct sk_buff_head *defq = &l->deferdq;
 	struct tipc_msg *hdr = buf_msg(skb);
 	u16 seqno, rcv_nxt, win_lim;
+	int released = 0;
 	int rc = 0;
 
 	/* Verify and update link state */
@@ -1559,25 +1767,23 @@
 		if (unlikely(!link_is_up(l))) {
 			if (l->state == LINK_ESTABLISHING)
 				rc = TIPC_LINK_UP_EVT;
-			goto drop;
+			kfree_skb(skb);
+			break;
 		}
 
 		/* Drop if outside receive window */
 		if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) {
 			l->stats.duplicates++;
-			goto drop;
+			kfree_skb(skb);
+			break;
 		}
-
-		/* Forward queues and wake up waiting users */
-		if (likely(tipc_link_release_pkts(l, msg_ack(hdr)))) {
-			tipc_link_advance_backlog(l, xmitq);
-			if (unlikely(!skb_queue_empty(&l->wakeupq)))
-				link_prepare_wakeup(l);
-		}
+		released += tipc_link_advance_transmq(l, l, msg_ack(hdr), 0,
+						      NULL, NULL, NULL, NULL);
 
 		/* Defer delivery if sequence gap */
 		if (unlikely(seqno != rcv_nxt)) {
-			__tipc_skb_queue_sorted(defq, seqno, skb);
+			if (!__tipc_skb_queue_sorted(defq, seqno, skb))
+				l->stats.duplicates++;
 			rc |= tipc_link_build_nack_msg(l, xmitq);
 			break;
 		}
@@ -1596,9 +1802,13 @@
 			break;
 	} while ((skb = __tipc_skb_dequeue(defq, l->rcv_nxt)));
 
-	return rc;
-drop:
-	kfree_skb(skb);
+	/* Forward queues and wake up waiting users */
+	if (released) {
+		tipc_link_update_cwin(l, released, 0);
+		tipc_link_advance_backlog(l, xmitq);
+		if (unlikely(!skb_queue_empty(&l->wakeupq)))
+			link_prepare_wakeup(l);
+	}
 	return rc;
 }
 
@@ -1607,15 +1817,15 @@
 				      int tolerance, int priority,
 				      struct sk_buff_head *xmitq)
 {
-	struct tipc_link *bcl = l->bc_rcvlink;
-	struct sk_buff *skb;
-	struct tipc_msg *hdr;
-	struct sk_buff_head *dfq = &l->deferdq;
-	bool node_up = link_is_up(bcl);
 	struct tipc_mon_state *mstate = &l->mon_state;
+	struct sk_buff_head *dfq = &l->deferdq;
+	struct tipc_link *bcl = l->bc_rcvlink;
+	struct tipc_msg *hdr;
+	struct sk_buff *skb;
+	bool node_up = link_is_up(bcl);
+	u16 glen = 0, bc_rcvgap = 0;
 	int dlen = 0;
 	void *data;
-	u16 glen = 0;
 
 	/* Don't send protocol message during reset or link failover */
 	if (tipc_link_is_blocked(l))
@@ -1624,7 +1834,7 @@
 	if (!tipc_link_is_up(l) && (mtyp == STATE_MSG))
 		return;
 
-	if (!skb_queue_empty(dfq))
+	if ((probe || probe_reply) && !skb_queue_empty(dfq))
 		rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt;
 
 	skb = tipc_msg_create(LINK_PROTOCOL, mtyp, INT_H_SIZE,
@@ -1653,11 +1863,12 @@
 		if (l->peer_caps & TIPC_LINK_PROTO_SEQNO)
 			msg_set_seqno(hdr, l->snd_nxt_state++);
 		msg_set_seq_gap(hdr, rcvgap);
-		msg_set_bc_gap(hdr, link_bc_rcv_gap(bcl));
+		bc_rcvgap = link_bc_rcv_gap(bcl);
+		msg_set_bc_gap(hdr, bc_rcvgap);
 		msg_set_probe(hdr, probe);
 		msg_set_is_keepalive(hdr, probe || probe_reply);
 		if (l->peer_caps & TIPC_GAP_ACK_BLOCK)
-			glen = tipc_build_gap_ack_blks(l, data);
+			glen = tipc_build_gap_ack_blks(l, hdr);
 		tipc_mon_prep(l->net, data + glen, &dlen, mstate, l->bearer_id);
 		msg_set_size(hdr, INT_H_SIZE + glen + dlen);
 		skb_trim(skb, INT_H_SIZE + glen + dlen);
@@ -1678,6 +1889,8 @@
 		l->stats.sent_probes++;
 	if (rcvgap)
 		l->stats.sent_nacks++;
+	if (bc_rcvgap)
+		bcl->stats.sent_nacks++;
 	skb->priority = TC_PRIO_CONTROL;
 	__skb_queue_tail(xmitq, skb);
 	trace_tipc_proto_build(skb, false, l->name);
@@ -1733,21 +1946,6 @@
 		return;
 
 	__skb_queue_head_init(&tnlq);
-	__skb_queue_head_init(&tmpxq);
-	__skb_queue_head_init(&frags);
-
-	/* 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, tipc_own_addr(l->net),
-			      0, 0, TIPC_ERR_NO_PORT);
-	if (!skb) {
-		pr_warn("%sunable to create tunnel packet\n", link_co_err);
-		return;
-	}
-	__skb_queue_tail(&tnlq, skb);
-	tipc_link_xmit(l, &tnlq, &tmpxq);
-	__skb_queue_purge(&tmpxq);
-
 	/* Link Synching:
 	 * From now on, send only one single ("dummy") SYNCH message
 	 * to peer. The SYNCH message does not contain any data, just
@@ -1773,6 +1971,20 @@
 		return;
 	}
 
+	__skb_queue_head_init(&tmpxq);
+	__skb_queue_head_init(&frags);
+	/* 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, tipc_own_addr(l->net),
+			      0, 0, TIPC_ERR_NO_PORT);
+	if (!skb) {
+		pr_warn("%sunable to create tunnel packet\n", link_co_err);
+		return;
+	}
+	__skb_queue_tail(&tnlq, skb);
+	tipc_link_xmit(l, &tnlq, &tmpxq);
+	__skb_queue_purge(&tmpxq);
+
 	/* Initialize reusable tunnel packet header */
 	tipc_msg_init(tipc_own_addr(l->net), &tnlhdr, TUNNEL_PROTOCOL,
 		      mtyp, INT_H_SIZE, l->addr);
@@ -1878,7 +2090,7 @@
 
 	tipc_link_create_dummy_tnl_msg(tnl, xmitq);
 
-	/* This failover link enpoint was never established before,
+	/* This failover link endpoint was never established before,
 	 * so it has not received anything from peer.
 	 * Otherwise, it must be a normal failover situation or the
 	 * node has entered SELF_DOWN_PEER_LEAVING and both peer nodes
@@ -1946,22 +2158,25 @@
 {
 	struct tipc_msg *hdr = buf_msg(skb);
 	struct tipc_gap_ack_blks *ga = NULL;
-	u16 rcvgap = 0;
-	u16 ack = msg_ack(hdr);
-	u16 gap = msg_seq_gap(hdr);
+	bool reply = msg_probe(hdr), retransmitted = false;
+	u32 dlen = msg_data_sz(hdr), glen = 0;
 	u16 peers_snd_nxt =  msg_next_sent(hdr);
 	u16 peers_tol = msg_link_tolerance(hdr);
 	u16 peers_prio = msg_linkprio(hdr);
+	u16 gap = msg_seq_gap(hdr);
+	u16 ack = msg_ack(hdr);
 	u16 rcv_nxt = l->rcv_nxt;
-	u16 dlen = msg_data_sz(hdr);
+	u16 rcvgap = 0;
 	int mtyp = msg_type(hdr);
-	bool reply = msg_probe(hdr);
-	u16 glen = 0;
-	void *data;
+	int rc = 0, released;
 	char *if_name;
-	int rc = 0;
+	void *data;
 
 	trace_tipc_proto_rcv(skb, false, l->name);
+
+	if (dlen > U16_MAX)
+		goto exit;
+
 	if (tipc_link_is_blocked(l) || !xmitq)
 		goto exit;
 
@@ -2030,6 +2245,11 @@
 		break;
 
 	case STATE_MSG:
+		/* Validate Gap ACK blocks, drop if invalid */
+		glen = tipc_get_gap_ack_blks(&ga, l, hdr, true);
+		if (glen > dlen)
+			break;
+
 		l->rcv_nxt_state = msg_seqno(hdr) + 1;
 
 		/* Update own tolerance if peer indicates a non-zero value */
@@ -2055,32 +2275,27 @@
 			break;
 		}
 
-		/* Receive Gap ACK blocks from peer if any */
-		if (l->peer_caps & TIPC_GAP_ACK_BLOCK) {
-			ga = (struct tipc_gap_ack_blks *)data;
-			glen = ntohs(ga->len);
-			/* sanity check: if failed, ignore Gap ACK blocks */
-			if (glen != tipc_gap_ack_blks_sz(ga->gack_cnt))
-				ga = NULL;
-		}
-
 		tipc_mon_rcv(l->net, data + glen, dlen - glen, l->addr,
 			     &l->mon_state, l->bearer_id);
 
 		/* Send NACK if peer has sent pkts we haven't received yet */
-		if (more(peers_snd_nxt, rcv_nxt) && !tipc_link_is_synching(l))
+		if ((reply || msg_is_keepalive(hdr)) &&
+		    more(peers_snd_nxt, rcv_nxt) &&
+		    !tipc_link_is_synching(l) &&
+		    skb_queue_empty(&l->deferdq))
 			rcvgap = peers_snd_nxt - l->rcv_nxt;
 		if (rcvgap || reply)
 			tipc_link_build_proto_msg(l, STATE_MSG, 0, reply,
 						  rcvgap, 0, 0, xmitq);
 
-		rc |= tipc_link_advance_transmq(l, ack, gap, ga, xmitq);
-
-		/* If NACK, retransmit will now start at right position */
+		released = tipc_link_advance_transmq(l, l, ack, gap, ga, xmitq,
+						     &retransmitted, &rc);
 		if (gap)
 			l->stats.recv_nacks++;
-
-		tipc_link_advance_backlog(l, xmitq);
+		if (released || retransmitted)
+			tipc_link_update_cwin(l, released, retransmitted);
+		if (released)
+			tipc_link_advance_backlog(l, xmitq);
 		if (unlikely(!skb_queue_empty(&l->wakeupq)))
 			link_prepare_wakeup(l);
 	}
@@ -2166,10 +2381,7 @@
 int tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
 			  struct sk_buff_head *xmitq)
 {
-	struct tipc_link *snd_l = l->bc_sndlink;
 	u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
-	u16 from = msg_bcast_ack(hdr) + 1;
-	u16 to = from + msg_bc_gap(hdr) - 1;
 	int rc = 0;
 
 	if (!link_is_up(l))
@@ -2185,14 +2397,10 @@
 	if (!l->bc_peer_is_up)
 		return rc;
 
-	l->stats.recv_nacks++;
-
 	/* Ignore if peers_snd_nxt goes beyond receive window */
 	if (more(peers_snd_nxt, l->rcv_nxt + l->window))
 		return rc;
 
-	rc = tipc_link_bc_retrans(snd_l, l, from, to, xmitq);
-
 	l->snd_nxt = peers_snd_nxt;
 	if (link_bc_rcv_gap(l))
 		rc |= TIPC_LINK_SND_STATE;
@@ -2227,38 +2435,34 @@
 	return 0;
 }
 
-void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
-			  struct sk_buff_head *xmitq)
+int tipc_link_bc_ack_rcv(struct tipc_link *r, u16 acked, u16 gap,
+			 struct tipc_gap_ack_blks *ga,
+			 struct sk_buff_head *xmitq,
+			 struct sk_buff_head *retrq)
 {
-	struct sk_buff *skb, *tmp;
-	struct tipc_link *snd_l = l->bc_sndlink;
+	struct tipc_link *l = r->bc_sndlink;
+	bool unused = false;
+	int rc = 0;
 
-	if (!link_is_up(l) || !l->bc_peer_is_up)
-		return;
+	if (!link_is_up(r) || !r->bc_peer_is_up)
+		return 0;
 
-	if (!more(acked, l->acked))
-		return;
-
-	trace_tipc_link_bc_ack(l, l->acked, acked, &snd_l->transmq);
-	/* Skip over packets peer has already acked */
-	skb_queue_walk(&snd_l->transmq, skb) {
-		if (more(buf_seqno(skb), l->acked))
-			break;
+	if (gap) {
+		l->stats.recv_nacks++;
+		r->stats.recv_nacks++;
 	}
 
-	/* Update/release the packets peer is acking now */
-	skb_queue_walk_from_safe(&snd_l->transmq, skb, tmp) {
-		if (more(buf_seqno(skb), acked))
-			break;
-		if (!--TIPC_SKB_CB(skb)->ackers) {
-			__skb_unlink(skb, &snd_l->transmq);
-			kfree_skb(skb);
-		}
-	}
-	l->acked = acked;
-	tipc_link_advance_backlog(snd_l, xmitq);
-	if (unlikely(!skb_queue_empty(&snd_l->wakeupq)))
-		link_prepare_wakeup(snd_l);
+	if (less(acked, r->acked) || (acked == r->acked && !gap && !ga))
+		return 0;
+
+	trace_tipc_link_bc_ack(r, acked, gap, &l->transmq);
+	tipc_link_advance_transmq(l, r, acked, gap, ga, retrq, &unused, &rc);
+
+	tipc_link_advance_backlog(l, xmitq);
+	if (unlikely(!skb_queue_empty(&l->wakeupq)))
+		link_prepare_wakeup(l);
+
+	return rc;
 }
 
 /* tipc_link_bc_nack_rcv(): receive broadcast nack message
@@ -2286,8 +2490,8 @@
 		return 0;
 
 	if (dnode == tipc_own_addr(l->net)) {
-		tipc_link_bc_ack_rcv(l, acked, xmitq);
-		rc = tipc_link_bc_retrans(l->bc_sndlink, l, from, to, xmitq);
+		rc = tipc_link_bc_ack_rcv(l, acked, to - acked, NULL, xmitq,
+					  xmitq);
 		l->stats.recv_nacks++;
 		return rc;
 	}
@@ -2299,15 +2503,18 @@
 	return 0;
 }
 
-void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
+void tipc_link_set_queue_limits(struct tipc_link *l, u32 min_win, u32 max_win)
 {
 	int max_bulk = TIPC_MAX_PUBL / (l->mtu / ITEM_SIZE);
 
-	l->window = win;
-	l->backlog[TIPC_LOW_IMPORTANCE].limit      = max_t(u16, 50, win);
-	l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = max_t(u16, 100, win * 2);
-	l->backlog[TIPC_HIGH_IMPORTANCE].limit     = max_t(u16, 150, win * 3);
-	l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = max_t(u16, 200, win * 4);
+	l->min_win = min_win;
+	l->ssthresh = max_win;
+	l->max_win = max_win;
+	l->window = min_win;
+	l->backlog[TIPC_LOW_IMPORTANCE].limit      = min_win * 2;
+	l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = min_win * 4;
+	l->backlog[TIPC_HIGH_IMPORTANCE].limit     = min_win * 6;
+	l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = min_win * 8;
 	l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
 }
 
@@ -2360,10 +2567,10 @@
 	}
 
 	if (props[TIPC_NLA_PROP_WIN]) {
-		u32 win;
+		u32 max_win;
 
-		win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
-		if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
+		max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
+		if (max_win < TIPC_DEF_LINK_WIN || max_win > TIPC_MAX_LINK_WIN)
 			return -EINVAL;
 	}
 
@@ -2556,16 +2763,15 @@
 	return -EMSGSIZE;
 }
 
-int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg)
+int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg,
+			struct tipc_link *bcl)
 {
 	int err;
 	void *hdr;
 	struct nlattr *attrs;
 	struct nlattr *prop;
-	struct tipc_net *tn = net_generic(net, tipc_net_id);
-	u32 bc_mode = tipc_bcast_get_broadcast_mode(net);
+	u32 bc_mode = tipc_bcast_get_mode(net);
 	u32 bc_ratio = tipc_bcast_get_broadcast_ratio(net);
-	struct tipc_link *bcl = tn->bcl;
 
 	if (!bcl)
 		return 0;
@@ -2599,7 +2805,7 @@
 	prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK_PROP);
 	if (!prop)
 		goto attr_msg_full;
-	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bcl->window))
+	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bcl->max_win))
 		goto prop_msg_full;
 	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_BROADCAST, bc_mode))
 		goto prop_msg_full;
@@ -2652,21 +2858,6 @@
 	l->abort_limit = limit;
 }
 
-char *tipc_link_name_ext(struct tipc_link *l, char *buf)
-{
-	if (!l)
-		scnprintf(buf, TIPC_MAX_LINK_NAME, "null");
-	else if (link_is_bc_sndlink(l))
-		scnprintf(buf, TIPC_MAX_LINK_NAME, "broadcast-sender");
-	else if (link_is_bc_rcvlink(l))
-		scnprintf(buf, TIPC_MAX_LINK_NAME,
-			  "broadcast-receiver, peer %x", l->addr);
-	else
-		memcpy(buf, l->name, TIPC_MAX_LINK_NAME);
-
-	return buf;
-}
-
 /**
  * tipc_link_dump - dump TIPC link data
  * @l: tipc link to be dumped