diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 366ce0b..4b92b19 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -46,8 +46,9 @@
 #include "bcast.h"
 #include "netlink.h"
 #include "group.h"
+#include "trace.h"
 
-#define CONN_TIMEOUT_DEFAULT	8000	/* default connect timeout = 8s */
+#define CONN_TIMEOUT_DEFAULT    8000    /* default connect timeout = 8s */
 #define CONN_PROBING_INTV	msecs_to_jiffies(3600000)  /* [ms] => 1 h */
 #define TIPC_FWD_MSG		1
 #define TIPC_MAX_PORT		0xffffffff
@@ -80,7 +81,6 @@
  * @publications: list of publications for port
  * @blocking_link: address of the congested link we are currently sleeping on
  * @pub_count: total # of publications port has made during its lifetime
- * @probing_state:
  * @conn_timeout: the time we can wait for an unresponded setup request
  * @dupl_rcvcnt: number of bytes counted twice, in both backlog and rcv queue
  * @cong_link_cnt: number of congested links
@@ -102,8 +102,8 @@
 	struct list_head cong_links;
 	struct list_head publications;
 	u32 pub_count;
-	uint conn_timeout;
 	atomic_t dupl_rcvcnt;
+	u16 conn_timeout;
 	bool probe_unacked;
 	u16 cong_link_cnt;
 	u16 snt_unacked;
@@ -234,6 +234,7 @@
  */
 static void tsk_advance_rx_queue(struct sock *sk)
 {
+	trace_tipc_sk_advance_rx(sk, NULL, TIPC_DUMP_SK_RCVQ, " ");
 	kfree_skb(__skb_dequeue(&sk->sk_receive_queue));
 }
 
@@ -248,6 +249,7 @@
 	if (!tipc_msg_reverse(onode, &skb, err))
 		return;
 
+	trace_tipc_sk_rej_msg(sk, skb, TIPC_DUMP_NONE, "@sk_respond!");
 	dnode = msg_destnode(buf_msg(skb));
 	selector = msg_origport(buf_msg(skb));
 	tipc_node_xmit_skb(sock_net(sk), skb, dnode, selector);
@@ -377,16 +379,18 @@
 
 #define tipc_wait_for_cond(sock_, timeo_, condition_)			       \
 ({                                                                             \
+	DEFINE_WAIT_FUNC(wait_, woken_wake_function);                          \
 	struct sock *sk_;						       \
 	int rc_;							       \
 									       \
 	while ((rc_ = !(condition_))) {					       \
-		DEFINE_WAIT_FUNC(wait_, woken_wake_function);	               \
+		/* coupled with smp_wmb() in tipc_sk_proto_rcv() */            \
+		smp_rmb();                                                     \
 		sk_ = (sock_)->sk;					       \
 		rc_ = tipc_sk_sock_err((sock_), timeo_);		       \
 		if (rc_)						       \
 			break;						       \
-		prepare_to_wait(sk_sleep(sk_), &wait_, TASK_INTERRUPTIBLE);    \
+		add_wait_queue(sk_sleep(sk_), &wait_);                         \
 		release_sock(sk_);					       \
 		*(timeo_) = wait_woken(&wait_, TASK_INTERRUPTIBLE, *(timeo_)); \
 		sched_annotate_sleep();				               \
@@ -482,7 +486,8 @@
 		if (sock->type == SOCK_DGRAM)
 			tsk_set_unreliable(tsk, true);
 	}
-
+	__skb_queue_head_init(&tsk->mc_method.deferredq);
+	trace_tipc_sk_create(sk, NULL, TIPC_DUMP_NONE, " ");
 	return 0;
 }
 
@@ -507,6 +512,9 @@
 	tipc_wait_for_cond(sock, &timeout, (!tsk->cong_link_cnt &&
 					    !tsk_conn_cong(tsk)));
 
+	/* Remove any pending SYN message */
+	__skb_queue_purge(&sk->sk_write_queue);
+
 	/* Reject all unreceived messages, except on an active connection
 	 * (which disconnects locally & sends a 'FIN+' to peer).
 	 */
@@ -569,10 +577,12 @@
 	tsk = tipc_sk(sk);
 	lock_sock(sk);
 
+	trace_tipc_sk_release(sk, NULL, TIPC_DUMP_ALL, " ");
 	__tipc_shutdown(sock, TIPC_ERR_NO_PORT);
 	sk->sk_shutdown = SHUTDOWN_MASK;
 	tipc_sk_leave(tsk);
 	tipc_sk_withdraw(tsk, 0, NULL);
+	__skb_queue_purge(&tsk->mc_method.deferredq);
 	sk_stop_timer(sk, &sk->sk_timer);
 	tipc_sk_remove(tsk);
 
@@ -716,6 +726,7 @@
 	__poll_t revents = 0;
 
 	sock_poll_wait(file, sock, wait);
+	trace_tipc_sk_poll(sk, NULL, TIPC_DUMP_ALL, " ");
 
 	if (sk->sk_shutdown & RCV_SHUTDOWN)
 		revents |= EPOLLRDHUP | EPOLLIN | EPOLLRDNORM;
@@ -724,12 +735,12 @@
 
 	switch (sk->sk_state) {
 	case TIPC_ESTABLISHED:
-	case TIPC_CONNECTING:
 		if (!tsk->cong_link_cnt && !tsk_conn_cong(tsk))
 			revents |= EPOLLOUT;
-		/* fall thru' */
+		/* fall through */
 	case TIPC_LISTEN:
-		if (!skb_queue_empty(&sk->sk_receive_queue))
+	case TIPC_CONNECTING:
+		if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
 			revents |= EPOLLIN | EPOLLRDNORM;
 		break;
 	case TIPC_OPEN:
@@ -737,7 +748,7 @@
 			revents |= EPOLLOUT;
 		if (!tipc_sk_type_connectionless(sk))
 			break;
-		if (skb_queue_empty(&sk->sk_receive_queue))
+		if (skb_queue_empty_lockless(&sk->sk_receive_queue))
 			break;
 		revents |= EPOLLIN | EPOLLRDNORM;
 		break;
@@ -798,13 +809,16 @@
 	msg_set_nameupper(hdr, seq->upper);
 
 	/* Build message as chain of buffers */
-	skb_queue_head_init(&pkts);
+	__skb_queue_head_init(&pkts);
 	rc = tipc_msg_build(hdr, msg, 0, dlen, mtu, &pkts);
 
 	/* Send message if build was successful */
-	if (unlikely(rc == dlen))
+	if (unlikely(rc == dlen)) {
+		trace_tipc_sk_sendmcast(sk, skb_peek(&pkts),
+					TIPC_DUMP_SK_SNDQ, " ");
 		rc = tipc_mcast_xmit(net, &pkts, method, &dsts,
 				     &tsk->cong_link_cnt);
+	}
 
 	tipc_nlist_purge(&dsts);
 
@@ -839,7 +853,7 @@
 	msg_set_grp_bc_seqno(hdr, bc_snd_nxt);
 
 	/* Build message as chain of buffers */
-	skb_queue_head_init(&pkts);
+	__skb_queue_head_init(&pkts);
 	mtu = tipc_node_get_mtu(net, dnode, tsk->portid);
 	rc = tipc_msg_build(hdr, m, 0, dlen, mtu, &pkts);
 	if (unlikely(rc != dlen))
@@ -878,7 +892,6 @@
 	DECLARE_SOCKADDR(struct sockaddr_tipc *, dest, m->msg_name);
 	int blks = tsk_blocks(GROUP_H_SIZE + dlen);
 	struct tipc_sock *tsk = tipc_sk(sk);
-	struct tipc_group *grp = tsk->group;
 	struct net *net = sock_net(sk);
 	struct tipc_member *mb = NULL;
 	u32 node, port;
@@ -892,7 +905,9 @@
 	/* Block or return if destination link or member is congested */
 	rc = tipc_wait_for_cond(sock, &timeout,
 				!tipc_dest_find(&tsk->cong_links, node, 0) &&
-				!tipc_group_cong(grp, node, port, blks, &mb));
+				tsk->group &&
+				!tipc_group_cong(tsk->group, node, port, blks,
+						 &mb));
 	if (unlikely(rc))
 		return rc;
 
@@ -922,7 +937,6 @@
 	struct tipc_sock *tsk = tipc_sk(sk);
 	struct list_head *cong_links = &tsk->cong_links;
 	int blks = tsk_blocks(GROUP_H_SIZE + dlen);
-	struct tipc_group *grp = tsk->group;
 	struct tipc_msg *hdr = &tsk->phdr;
 	struct tipc_member *first = NULL;
 	struct tipc_member *mbr = NULL;
@@ -939,9 +953,10 @@
 	type = msg_nametype(hdr);
 	inst = dest->addr.name.name.instance;
 	scope = msg_lookup_scope(hdr);
-	exclude = tipc_group_exclude(grp);
 
 	while (++lookups < 4) {
+		exclude = tipc_group_exclude(tsk->group);
+
 		first = NULL;
 
 		/* Look for a non-congested destination member, if any */
@@ -950,7 +965,8 @@
 						 &dstcnt, exclude, false))
 				return -EHOSTUNREACH;
 			tipc_dest_pop(&dsts, &node, &port);
-			cong = tipc_group_cong(grp, node, port, blks, &mbr);
+			cong = tipc_group_cong(tsk->group, node, port, blks,
+					       &mbr);
 			if (!cong)
 				break;
 			if (mbr == first)
@@ -969,7 +985,8 @@
 		/* Block or return if destination link or member is congested */
 		rc = tipc_wait_for_cond(sock, &timeout,
 					!tipc_dest_find(cong_links, node, 0) &&
-					!tipc_group_cong(grp, node, port,
+					tsk->group &&
+					!tipc_group_cong(tsk->group, node, port,
 							 blks, &mbr));
 		if (unlikely(rc))
 			return rc;
@@ -1004,8 +1021,7 @@
 	struct sock *sk = sock->sk;
 	struct net *net = sock_net(sk);
 	struct tipc_sock *tsk = tipc_sk(sk);
-	struct tipc_group *grp = tsk->group;
-	struct tipc_nlist *dsts = tipc_group_dests(grp);
+	struct tipc_nlist *dsts;
 	struct tipc_mc_method *method = &tsk->mc_method;
 	bool ack = method->mandatory && method->rcast;
 	int blks = tsk_blocks(MCAST_H_SIZE + dlen);
@@ -1014,15 +1030,17 @@
 	struct sk_buff_head pkts;
 	int rc = -EHOSTUNREACH;
 
-	if (!dsts->local && !dsts->remote)
-		return -EHOSTUNREACH;
-
 	/* Block or return if any destination link or member is congested */
-	rc = tipc_wait_for_cond(sock, &timeout,	!tsk->cong_link_cnt &&
-				!tipc_group_bc_cong(grp, blks));
+	rc = tipc_wait_for_cond(sock, &timeout,
+				!tsk->cong_link_cnt && tsk->group &&
+				!tipc_group_bc_cong(tsk->group, blks));
 	if (unlikely(rc))
 		return rc;
 
+	dsts = tipc_group_dests(tsk->group);
+	if (!dsts->local && !dsts->remote)
+		return -EHOSTUNREACH;
+
 	/* Complete message header */
 	if (dest) {
 		msg_set_type(hdr, TIPC_GRP_MCAST_MSG);
@@ -1034,13 +1052,13 @@
 	msg_set_hdr_sz(hdr, GROUP_H_SIZE);
 	msg_set_destport(hdr, 0);
 	msg_set_destnode(hdr, 0);
-	msg_set_grp_bc_seqno(hdr, tipc_group_bc_snd_nxt(grp));
+	msg_set_grp_bc_seqno(hdr, tipc_group_bc_snd_nxt(tsk->group));
 
 	/* Avoid getting stuck with repeated forced replicasts */
 	msg_set_grp_bc_ack_req(hdr, ack);
 
 	/* Build message as chain of buffers */
-	skb_queue_head_init(&pkts);
+	__skb_queue_head_init(&pkts);
 	rc = tipc_msg_build(hdr, m, 0, dlen, mtu, &pkts);
 	if (unlikely(rc != dlen))
 		return rc;
@@ -1206,8 +1224,10 @@
 	bool conn_cong;
 
 	/* Ignore if connection cannot be validated: */
-	if (!tsk_peer_msg(tsk, hdr))
+	if (!tsk_peer_msg(tsk, hdr)) {
+		trace_tipc_sk_drop_msg(sk, skb, TIPC_DUMP_NONE, "@proto_rcv!");
 		goto exit;
+	}
 
 	if (unlikely(msg_errcode(hdr))) {
 		tipc_set_sk_state(sk, TIPC_DISCONNECTING);
@@ -1314,7 +1334,7 @@
 
 	if (unlikely(!dest)) {
 		dest = &tsk->peer;
-		if (!syn || dest->family != AF_TIPC)
+		if (!syn && dest->family != AF_TIPC)
 			return -EDESTADDRREQ;
 	}
 
@@ -1329,6 +1349,7 @@
 			tsk->conn_type = dest->addr.name.name.type;
 			tsk->conn_instance = dest->addr.name.name.instance;
 		}
+		msg_set_syn(hdr, 1);
 	}
 
 	seq = &dest->addr.nameseq;
@@ -1366,12 +1387,15 @@
 	if (unlikely(rc))
 		return rc;
 
-	skb_queue_head_init(&pkts);
+	__skb_queue_head_init(&pkts);
 	mtu = tipc_node_get_mtu(net, dnode, tsk->portid);
 	rc = tipc_msg_build(hdr, m, 0, dlen, mtu, &pkts);
 	if (unlikely(rc != dlen))
 		return rc;
+	if (unlikely(syn && !tipc_msg_skb_clone(&pkts, &sk->sk_write_queue)))
+		return -ENOMEM;
 
+	trace_tipc_sk_sendmsg(sk, skb_peek(&pkts), TIPC_DUMP_SK_SNDQ, " ");
 	rc = tipc_node_xmit(net, &pkts, dnode, tsk->portid);
 	if (unlikely(rc == -ELINKCONG)) {
 		tipc_dest_push(clinks, dnode, 0);
@@ -1421,7 +1445,7 @@
 	int send, sent = 0;
 	int rc = 0;
 
-	skb_queue_head_init(&pkts);
+	__skb_queue_head_init(&pkts);
 
 	if (unlikely(dlen > INT_MAX))
 		return -EMSGSIZE;
@@ -1449,6 +1473,8 @@
 		if (unlikely(rc != send))
 			break;
 
+		trace_tipc_sk_sendstream(sk, skb_peek(&pkts),
+					 TIPC_DUMP_SK_SNDQ, " ");
 		rc = tipc_node_xmit(net, &pkts, dnode, tsk->portid);
 		if (unlikely(rc == -ELINKCONG)) {
 			tsk->cong_link_cnt = 1;
@@ -1490,6 +1516,7 @@
 	struct net *net = sock_net(sk);
 	struct tipc_msg *msg = &tsk->phdr;
 
+	msg_set_syn(msg, 0);
 	msg_set_destnode(msg, peer_node);
 	msg_set_destport(msg, peer_port);
 	msg_set_type(msg, TIPC_CONN_MSG);
@@ -1501,6 +1528,7 @@
 	tipc_node_add_conn(net, peer_node, tsk->portid, peer_port);
 	tsk->max_pkt = tipc_node_get_mtu(net, peer_node, tsk->portid);
 	tsk->peer_caps = tipc_node_get_capabilities(net, peer_node);
+	__skb_queue_purge(&sk->sk_write_queue);
 	if (tsk->peer_caps & TIPC_BLOCK_FLOWCTL)
 		return;
 
@@ -1652,7 +1680,7 @@
 static int tipc_wait_for_rcvmsg(struct socket *sock, long *timeop)
 {
 	struct sock *sk = sock->sk;
-	DEFINE_WAIT(wait);
+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
 	long timeo = *timeop;
 	int err = sock_error(sk);
 
@@ -1660,15 +1688,17 @@
 		return err;
 
 	for (;;) {
-		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 		if (timeo && skb_queue_empty(&sk->sk_receive_queue)) {
 			if (sk->sk_shutdown & RCV_SHUTDOWN) {
 				err = -ENOTCONN;
 				break;
 			}
+			add_wait_queue(sk_sleep(sk), &wait);
 			release_sock(sk);
-			timeo = schedule_timeout(timeo);
+			timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
+			sched_annotate_sleep();
 			lock_sock(sk);
+			remove_wait_queue(sk_sleep(sk), &wait);
 		}
 		err = 0;
 		if (!skb_queue_empty(&sk->sk_receive_queue))
@@ -1684,7 +1714,6 @@
 		if (err)
 			break;
 	}
-	finish_wait(sk_sleep(sk), &wait);
 	*timeop = timeo;
 	return err;
 }
@@ -1776,7 +1805,7 @@
 
 	/* Send group flow control advertisement when applicable */
 	if (tsk->group && msg_in_group(hdr) && !grp_evt) {
-		skb_queue_head_init(&xmitq);
+		__skb_queue_head_init(&xmitq);
 		tipc_group_update_rcv_win(tsk->group, tsk_blocks(hlen + dlen),
 					  msg_orignode(hdr), msg_origport(hdr),
 					  &xmitq);
@@ -1957,6 +1986,8 @@
 		return;
 	case SOCK_WAKEUP:
 		tipc_dest_del(&tsk->cong_links, msg_orignode(hdr), 0);
+		/* coupled with smp_rmb() in tipc_wait_for_cond() */
+		smp_wmb();
 		tsk->cong_link_cnt--;
 		wakeup = true;
 		break;
@@ -1978,91 +2009,90 @@
 }
 
 /**
- * tipc_filter_connect - Handle incoming message for a connection-based socket
+ * tipc_sk_filter_connect - check incoming message for a connection-based socket
  * @tsk: TIPC socket
- * @skb: pointer to message buffer. Set to NULL if buffer is consumed
- *
- * Returns true if everything ok, false otherwise
+ * @skb: pointer to message buffer.
+ * Returns true if message should be added to receive queue, false otherwise
  */
 static bool tipc_sk_filter_connect(struct tipc_sock *tsk, struct sk_buff *skb)
 {
 	struct sock *sk = &tsk->sk;
 	struct net *net = sock_net(sk);
 	struct tipc_msg *hdr = buf_msg(skb);
-	u32 pport = msg_origport(hdr);
-	u32 pnode = msg_orignode(hdr);
+	bool con_msg = msg_connected(hdr);
+	u32 pport = tsk_peer_port(tsk);
+	u32 pnode = tsk_peer_node(tsk);
+	u32 oport = msg_origport(hdr);
+	u32 onode = msg_orignode(hdr);
+	int err = msg_errcode(hdr);
+	unsigned long delay;
 
 	if (unlikely(msg_mcast(hdr)))
 		return false;
 
 	switch (sk->sk_state) {
 	case TIPC_CONNECTING:
-		/* Accept only ACK or NACK message */
-		if (unlikely(!msg_connected(hdr))) {
-			if (pport != tsk_peer_port(tsk) ||
-			    pnode != tsk_peer_node(tsk))
-				return false;
-
-			tipc_set_sk_state(sk, TIPC_DISCONNECTING);
-			sk->sk_err = ECONNREFUSED;
+		/* Setup ACK */
+		if (likely(con_msg)) {
+			if (err)
+				break;
+			tipc_sk_finish_conn(tsk, oport, onode);
+			msg_set_importance(&tsk->phdr, msg_importance(hdr));
+			/* ACK+ message with data is added to receive queue */
+			if (msg_data_sz(hdr))
+				return true;
+			/* Empty ACK-, - wake up sleeping connect() and drop */
 			sk->sk_state_change(sk);
-			return true;
+			msg_set_dest_droppable(hdr, 1);
+			return false;
 		}
-
-		if (unlikely(msg_errcode(hdr))) {
-			tipc_set_sk_state(sk, TIPC_DISCONNECTING);
-			sk->sk_err = ECONNREFUSED;
-			sk->sk_state_change(sk);
-			return true;
-		}
-
-		if (unlikely(!msg_isdata(hdr))) {
-			tipc_set_sk_state(sk, TIPC_DISCONNECTING);
-			sk->sk_err = EINVAL;
-			sk->sk_state_change(sk);
-			return true;
-		}
-
-		tipc_sk_finish_conn(tsk, msg_origport(hdr), msg_orignode(hdr));
-		msg_set_importance(&tsk->phdr, msg_importance(hdr));
-
-		/* If 'ACK+' message, add to socket receive queue */
-		if (msg_data_sz(hdr))
-			return true;
-
-		/* If empty 'ACK-' message, wake up sleeping connect() */
-		sk->sk_data_ready(sk);
-
-		/* 'ACK-' message is neither accepted nor rejected: */
-		msg_set_dest_droppable(hdr, 1);
-		return false;
-
-	case TIPC_OPEN:
-	case TIPC_DISCONNECTING:
-		break;
-	case TIPC_LISTEN:
-		/* Accept only SYN message */
-		if (!msg_connected(hdr) && !(msg_errcode(hdr)))
-			return true;
-		break;
-	case TIPC_ESTABLISHED:
-		/* Accept only connection-based messages sent by peer */
-		if (unlikely(!tsk_peer_msg(tsk, hdr)))
+		/* Ignore connectionless message if not from listening socket */
+		if (oport != pport || onode != pnode)
 			return false;
 
-		if (unlikely(msg_errcode(hdr))) {
-			tipc_set_sk_state(sk, TIPC_DISCONNECTING);
-			/* Let timer expire on it's own */
-			tipc_node_remove_conn(net, tsk_peer_node(tsk),
-					      tsk->portid);
-			sk->sk_state_change(sk);
-		}
+		/* Rejected SYN */
+		if (err != TIPC_ERR_OVERLOAD)
+			break;
+
+		/* Prepare for new setup attempt if we have a SYN clone */
+		if (skb_queue_empty(&sk->sk_write_queue))
+			break;
+		get_random_bytes(&delay, 2);
+		delay %= (tsk->conn_timeout / 4);
+		delay = msecs_to_jiffies(delay + 100);
+		sk_reset_timer(sk, &sk->sk_timer, jiffies + delay);
+		return false;
+	case TIPC_OPEN:
+	case TIPC_DISCONNECTING:
+		return false;
+	case TIPC_LISTEN:
+		/* Accept only SYN message */
+		if (!msg_is_syn(hdr) &&
+		    tipc_node_get_capabilities(net, onode) & TIPC_SYN_BIT)
+			return false;
+		if (!con_msg && !err)
+			return true;
+		return false;
+	case TIPC_ESTABLISHED:
+		/* Accept only connection-based messages sent by peer */
+		if (likely(con_msg && !err && pport == oport && pnode == onode))
+			return true;
+		if (!tsk_peer_msg(tsk, hdr))
+			return false;
+		if (!err)
+			return true;
+		tipc_set_sk_state(sk, TIPC_DISCONNECTING);
+		tipc_node_remove_conn(net, pnode, tsk->portid);
+		sk->sk_state_change(sk);
 		return true;
 	default:
 		pr_err("Unknown sk_state %u\n", sk->sk_state);
 	}
-
-	return false;
+	/* Abort connection setup attempt */
+	tipc_set_sk_state(sk, TIPC_DISCONNECTING);
+	sk->sk_err = ECONNREFUSED;
+	sk->sk_state_change(sk);
+	return true;
 }
 
 /**
@@ -2089,13 +2119,13 @@
 	struct tipc_msg *hdr = buf_msg(skb);
 
 	if (unlikely(msg_in_group(hdr)))
-		return sk->sk_rcvbuf;
+		return READ_ONCE(sk->sk_rcvbuf);
 
 	if (unlikely(!msg_connected(hdr)))
-		return sk->sk_rcvbuf << msg_importance(hdr);
+		return READ_ONCE(sk->sk_rcvbuf) << msg_importance(hdr);
 
 	if (likely(tsk->peer_caps & TIPC_BLOCK_FLOWCTL))
-		return sk->sk_rcvbuf;
+		return READ_ONCE(sk->sk_rcvbuf);
 
 	return FLOWCTL_MSG_LIM;
 }
@@ -2120,8 +2150,10 @@
 	struct tipc_msg *hdr = buf_msg(skb);
 	struct net *net = sock_net(sk);
 	struct sk_buff_head inputq;
+	int mtyp = msg_type(hdr);
 	int limit, err = TIPC_OK;
 
+	trace_tipc_sk_filter_rcv(sk, skb, TIPC_DUMP_ALL, " ");
 	TIPC_SKB_CB(skb)->bytes_read = 0;
 	__skb_queue_head_init(&inputq);
 	__skb_queue_tail(&inputq, skb);
@@ -2132,6 +2164,9 @@
 	if (unlikely(grp))
 		tipc_group_filter_msg(grp, &inputq, xmitq);
 
+	if (unlikely(!grp) && mtyp == TIPC_MCAST_MSG)
+		tipc_mcast_filter_msg(net, &tsk->mc_method.deferredq, &inputq);
+
 	/* Validate and add to receive buffer if there is space */
 	while ((skb = __skb_dequeue(&inputq))) {
 		hdr = buf_msg(skb);
@@ -2141,17 +2176,25 @@
 		    (!grp && msg_in_group(hdr)))
 			err = TIPC_ERR_NO_PORT;
 		else if (sk_rmem_alloc_get(sk) + skb->truesize >= limit) {
+			trace_tipc_sk_dump(sk, skb, TIPC_DUMP_ALL,
+					   "err_overload2!");
 			atomic_inc(&sk->sk_drops);
 			err = TIPC_ERR_OVERLOAD;
 		}
 
 		if (unlikely(err)) {
-			tipc_skb_reject(net, err, skb, xmitq);
+			if (tipc_msg_reverse(tipc_own_addr(net), &skb, err)) {
+				trace_tipc_sk_rej_msg(sk, skb, TIPC_DUMP_NONE,
+						      "@filter_rcv!");
+				__skb_queue_tail(xmitq, skb);
+			}
 			err = TIPC_OK;
 			continue;
 		}
 		__skb_queue_tail(&sk->sk_receive_queue, skb);
 		skb_set_owner_r(skb, sk);
+		trace_tipc_sk_overlimit2(sk, skb, TIPC_DUMP_ALL,
+					 "rcvq >90% allocated!");
 		sk->sk_data_ready(sk);
 	}
 }
@@ -2217,14 +2260,21 @@
 		if (!sk->sk_backlog.len)
 			atomic_set(dcnt, 0);
 		lim = rcvbuf_limit(sk, skb) + atomic_read(dcnt);
-		if (likely(!sk_add_backlog(sk, skb, lim)))
+		if (likely(!sk_add_backlog(sk, skb, lim))) {
+			trace_tipc_sk_overlimit1(sk, skb, TIPC_DUMP_ALL,
+						 "bklg & rcvq >90% allocated!");
 			continue;
+		}
 
+		trace_tipc_sk_dump(sk, skb, TIPC_DUMP_ALL, "err_overload!");
 		/* Overload => reject message back to sender */
 		onode = tipc_own_addr(sock_net(sk));
 		atomic_inc(&sk->sk_drops);
-		if (tipc_msg_reverse(onode, &skb, TIPC_ERR_OVERLOAD))
+		if (tipc_msg_reverse(onode, &skb, TIPC_ERR_OVERLOAD)) {
+			trace_tipc_sk_rej_msg(sk, skb, TIPC_DUMP_ALL,
+					      "@sk_enqueue!");
 			__skb_queue_tail(xmitq, skb);
+		}
 		break;
 	}
 }
@@ -2273,6 +2323,8 @@
 		/* Prepare for message rejection */
 		if (!tipc_msg_reverse(tipc_own_addr(net), &skb, err))
 			continue;
+
+		trace_tipc_sk_rej_msg(NULL, skb, TIPC_DUMP_NONE, "@sk_rcv!");
 xmit:
 		dnode = msg_destnode(buf_msg(skb));
 		tipc_node_xmit_skb(net, skb, dnode, dport);
@@ -2302,6 +2354,16 @@
 	return 0;
 }
 
+static bool tipc_sockaddr_is_sane(struct sockaddr_tipc *addr)
+{
+	if (addr->family != AF_TIPC)
+		return false;
+	if (addr->addrtype == TIPC_SERVICE_RANGE)
+		return (addr->addr.nameseq.lower <= addr->addr.nameseq.upper);
+	return (addr->addrtype == TIPC_SERVICE_ADDR ||
+		addr->addrtype == TIPC_SOCKET_ADDR);
+}
+
 /**
  * tipc_connect - establish a connection to another TIPC port
  * @sock: socket structure
@@ -2337,18 +2399,18 @@
 		if (!tipc_sk_type_connectionless(sk))
 			res = -EINVAL;
 		goto exit;
-	} else if (dst->family != AF_TIPC) {
-		res = -EINVAL;
 	}
-	if (dst->addrtype != TIPC_ADDR_ID && dst->addrtype != TIPC_ADDR_NAME)
+	if (!tipc_sockaddr_is_sane(dst)) {
 		res = -EINVAL;
-	if (res)
 		goto exit;
-
+	}
 	/* DGRAM/RDM connect(), just save the destaddr */
 	if (tipc_sk_type_connectionless(sk)) {
 		memcpy(&tsk->peer, dest, destlen);
 		goto exit;
+	} else if (dst->addrtype == TIPC_SERVICE_RANGE) {
+		res = -EINVAL;
+		goto exit;
 	}
 
 	previous = sk->sk_state;
@@ -2374,7 +2436,7 @@
 		 * case is EINPROGRESS, rather than EALREADY.
 		 */
 		res = -EINPROGRESS;
-		/* fall thru' */
+		/* fall through */
 	case TIPC_CONNECTING:
 		if (!timeout) {
 			if (previous == TIPC_CONNECTING)
@@ -2546,6 +2608,7 @@
 
 	lock_sock(sk);
 
+	trace_tipc_sk_shutdown(sk, NULL, TIPC_DUMP_ALL, " ");
 	__tipc_shutdown(sock, TIPC_CONN_SHUTDOWN);
 	sk->sk_shutdown = SEND_SHUTDOWN;
 
@@ -2564,43 +2627,78 @@
 	return res;
 }
 
+static void tipc_sk_check_probing_state(struct sock *sk,
+					struct sk_buff_head *list)
+{
+	struct tipc_sock *tsk = tipc_sk(sk);
+	u32 pnode = tsk_peer_node(tsk);
+	u32 pport = tsk_peer_port(tsk);
+	u32 self = tsk_own_node(tsk);
+	u32 oport = tsk->portid;
+	struct sk_buff *skb;
+
+	if (tsk->probe_unacked) {
+		tipc_set_sk_state(sk, TIPC_DISCONNECTING);
+		sk->sk_err = ECONNABORTED;
+		tipc_node_remove_conn(sock_net(sk), pnode, pport);
+		sk->sk_state_change(sk);
+		return;
+	}
+	/* Prepare new probe */
+	skb = tipc_msg_create(CONN_MANAGER, CONN_PROBE, INT_H_SIZE, 0,
+			      pnode, self, pport, oport, TIPC_OK);
+	if (skb)
+		__skb_queue_tail(list, skb);
+	tsk->probe_unacked = true;
+	sk_reset_timer(sk, &sk->sk_timer, jiffies + CONN_PROBING_INTV);
+}
+
+static void tipc_sk_retry_connect(struct sock *sk, struct sk_buff_head *list)
+{
+	struct tipc_sock *tsk = tipc_sk(sk);
+
+	/* Try again later if dest link is congested */
+	if (tsk->cong_link_cnt) {
+		sk_reset_timer(sk, &sk->sk_timer, msecs_to_jiffies(100));
+		return;
+	}
+	/* Prepare SYN for retransmit */
+	tipc_msg_skb_clone(&sk->sk_write_queue, list);
+}
+
 static void tipc_sk_timeout(struct timer_list *t)
 {
 	struct sock *sk = from_timer(sk, t, sk_timer);
 	struct tipc_sock *tsk = tipc_sk(sk);
-	u32 peer_port = tsk_peer_port(tsk);
-	u32 peer_node = tsk_peer_node(tsk);
-	u32 own_node = tsk_own_node(tsk);
-	u32 own_port = tsk->portid;
-	struct net *net = sock_net(sk);
-	struct sk_buff *skb = NULL;
+	u32 pnode = tsk_peer_node(tsk);
+	struct sk_buff_head list;
+	int rc = 0;
 
+	__skb_queue_head_init(&list);
 	bh_lock_sock(sk);
-	if (!tipc_sk_connected(sk))
-		goto exit;
 
 	/* Try again later if socket is busy */
 	if (sock_owned_by_user(sk)) {
 		sk_reset_timer(sk, &sk->sk_timer, jiffies + HZ / 20);
-		goto exit;
+		bh_unlock_sock(sk);
+		return;
 	}
 
-	if (tsk->probe_unacked) {
-		tipc_set_sk_state(sk, TIPC_DISCONNECTING);
-		tipc_node_remove_conn(net, peer_node, peer_port);
-		sk->sk_state_change(sk);
-		goto exit;
-	}
-	/* Send new probe */
-	skb = tipc_msg_create(CONN_MANAGER, CONN_PROBE, INT_H_SIZE, 0,
-			      peer_node, own_node, peer_port, own_port,
-			      TIPC_OK);
-	tsk->probe_unacked = true;
-	sk_reset_timer(sk, &sk->sk_timer, jiffies + CONN_PROBING_INTV);
-exit:
+	if (sk->sk_state == TIPC_ESTABLISHED)
+		tipc_sk_check_probing_state(sk, &list);
+	else if (sk->sk_state == TIPC_CONNECTING)
+		tipc_sk_retry_connect(sk, &list);
+
 	bh_unlock_sock(sk);
-	if (skb)
-		tipc_node_xmit_skb(net, skb, peer_node, own_port);
+
+	if (!skb_queue_empty(&list))
+		rc = tipc_node_xmit(sock_net(sk), &list, pnode, tsk->portid);
+
+	/* SYN messages may cause link congestion */
+	if (rc == -ELINKCONG) {
+		tipc_dest_push(&tsk->cong_links, pnode, 0);
+		tsk->cong_link_cnt = 1;
+	}
 	sock_put(sk);
 }
 
@@ -2683,11 +2781,15 @@
 		rhashtable_walk_start(&iter);
 
 		while ((tsk = rhashtable_walk_next(&iter)) && !IS_ERR(tsk)) {
-			spin_lock_bh(&tsk->sk.sk_lock.slock);
+			sock_hold(&tsk->sk);
+			rhashtable_walk_stop(&iter);
+			lock_sock(&tsk->sk);
 			msg = &tsk->phdr;
 			msg_set_prevnode(msg, tipc_own_addr(net));
 			msg_set_orignode(msg, tipc_own_addr(net));
-			spin_unlock_bh(&tsk->sk.sk_lock.slock);
+			release_sock(&tsk->sk);
+			rhashtable_walk_start(&iter);
+			sock_put(&tsk->sk);
 		}
 
 		rhashtable_walk_stop(&iter);
@@ -2967,6 +3069,9 @@
 	case TIPC_SOCK_RECVQ_DEPTH:
 		value = skb_queue_len(&sk->sk_receive_queue);
 		break;
+	case TIPC_SOCK_RECVQ_USED:
+		value = sk_rmem_alloc_get(sk);
+		break;
 	case TIPC_GROUP_JOIN:
 		seq.type = 0;
 		if (tsk->group)
@@ -3167,7 +3272,9 @@
 	peer_node = tsk_peer_node(tsk);
 	peer_port = tsk_peer_port(tsk);
 
-	nest = nla_nest_start(skb, TIPC_NLA_SOCK_CON);
+	nest = nla_nest_start_noflag(skb, TIPC_NLA_SOCK_CON);
+	if (!nest)
+		return -EMSGSIZE;
 
 	if (nla_put_u32(skb, TIPC_NLA_CON_NODE, peer_node))
 		goto msg_full;
@@ -3224,7 +3331,7 @@
 	if (!hdr)
 		goto msg_cancel;
 
-	attrs = nla_nest_start(skb, TIPC_NLA_SOCK);
+	attrs = nla_nest_start_noflag(skb, TIPC_NLA_SOCK);
 	if (!attrs)
 		goto genlmsg_cancel;
 
@@ -3329,7 +3436,7 @@
 	if (!(sk_filter_state & (1 << sk->sk_state)))
 		return 0;
 
-	attrs = nla_nest_start(skb, TIPC_NLA_SOCK);
+	attrs = nla_nest_start_noflag(skb, TIPC_NLA_SOCK);
 	if (!attrs)
 		goto msg_cancel;
 
@@ -3347,7 +3454,7 @@
 			      TIPC_NLA_SOCK_PAD))
 		goto attr_msg_cancel;
 
-	stat = nla_nest_start(skb, TIPC_NLA_SOCK_STAT);
+	stat = nla_nest_start_noflag(skb, TIPC_NLA_SOCK_STAT);
 	if (!stat)
 		goto attr_msg_cancel;
 
@@ -3404,7 +3511,7 @@
 	if (!hdr)
 		goto msg_cancel;
 
-	attrs = nla_nest_start(skb, TIPC_NLA_PUBL);
+	attrs = nla_nest_start_noflag(skb, TIPC_NLA_PUBL);
 	if (!attrs)
 		goto genlmsg_cancel;
 
@@ -3491,9 +3598,9 @@
 		if (!attrs[TIPC_NLA_SOCK])
 			return -EINVAL;
 
-		err = nla_parse_nested(sock, TIPC_NLA_SOCK_MAX,
-				       attrs[TIPC_NLA_SOCK],
-				       tipc_nl_sock_policy, NULL);
+		err = nla_parse_nested_deprecated(sock, TIPC_NLA_SOCK_MAX,
+						  attrs[TIPC_NLA_SOCK],
+						  tipc_nl_sock_policy, NULL);
 		if (err)
 			return err;
 
@@ -3523,3 +3630,187 @@
 
 	return skb->len;
 }
+
+/**
+ * tipc_sk_filtering - check if a socket should be traced
+ * @sk: the socket to be examined
+ * @sysctl_tipc_sk_filter[]: the socket tuple for filtering,
+ *  (portid, sock type, name type, name lower, name upper)
+ *
+ * Returns true if the socket meets the socket tuple data
+ * (value 0 = 'any') or when there is no tuple set (all = 0),
+ * otherwise false
+ */
+bool tipc_sk_filtering(struct sock *sk)
+{
+	struct tipc_sock *tsk;
+	struct publication *p;
+	u32 _port, _sktype, _type, _lower, _upper;
+	u32 type = 0, lower = 0, upper = 0;
+
+	if (!sk)
+		return true;
+
+	tsk = tipc_sk(sk);
+
+	_port = sysctl_tipc_sk_filter[0];
+	_sktype = sysctl_tipc_sk_filter[1];
+	_type = sysctl_tipc_sk_filter[2];
+	_lower = sysctl_tipc_sk_filter[3];
+	_upper = sysctl_tipc_sk_filter[4];
+
+	if (!_port && !_sktype && !_type && !_lower && !_upper)
+		return true;
+
+	if (_port)
+		return (_port == tsk->portid);
+
+	if (_sktype && _sktype != sk->sk_type)
+		return false;
+
+	if (tsk->published) {
+		p = list_first_entry_or_null(&tsk->publications,
+					     struct publication, binding_sock);
+		if (p) {
+			type = p->type;
+			lower = p->lower;
+			upper = p->upper;
+		}
+	}
+
+	if (!tipc_sk_type_connectionless(sk)) {
+		type = tsk->conn_type;
+		lower = tsk->conn_instance;
+		upper = tsk->conn_instance;
+	}
+
+	if ((_type && _type != type) || (_lower && _lower != lower) ||
+	    (_upper && _upper != upper))
+		return false;
+
+	return true;
+}
+
+u32 tipc_sock_get_portid(struct sock *sk)
+{
+	return (sk) ? (tipc_sk(sk))->portid : 0;
+}
+
+/**
+ * tipc_sk_overlimit1 - check if socket rx queue is about to be overloaded,
+ *			both the rcv and backlog queues are considered
+ * @sk: tipc sk to be checked
+ * @skb: tipc msg to be checked
+ *
+ * Returns true if the socket rx queue allocation is > 90%, otherwise false
+ */
+
+bool tipc_sk_overlimit1(struct sock *sk, struct sk_buff *skb)
+{
+	atomic_t *dcnt = &tipc_sk(sk)->dupl_rcvcnt;
+	unsigned int lim = rcvbuf_limit(sk, skb) + atomic_read(dcnt);
+	unsigned int qsize = sk->sk_backlog.len + sk_rmem_alloc_get(sk);
+
+	return (qsize > lim * 90 / 100);
+}
+
+/**
+ * tipc_sk_overlimit2 - check if socket rx queue is about to be overloaded,
+ *			only the rcv queue is considered
+ * @sk: tipc sk to be checked
+ * @skb: tipc msg to be checked
+ *
+ * Returns true if the socket rx queue allocation is > 90%, otherwise false
+ */
+
+bool tipc_sk_overlimit2(struct sock *sk, struct sk_buff *skb)
+{
+	unsigned int lim = rcvbuf_limit(sk, skb);
+	unsigned int qsize = sk_rmem_alloc_get(sk);
+
+	return (qsize > lim * 90 / 100);
+}
+
+/**
+ * tipc_sk_dump - dump TIPC socket
+ * @sk: tipc sk to be dumped
+ * @dqueues: bitmask to decide if any socket queue to be dumped?
+ *           - TIPC_DUMP_NONE: don't dump socket queues
+ *           - TIPC_DUMP_SK_SNDQ: dump socket send queue
+ *           - TIPC_DUMP_SK_RCVQ: dump socket rcv queue
+ *           - TIPC_DUMP_SK_BKLGQ: dump socket backlog queue
+ *           - TIPC_DUMP_ALL: dump all the socket queues above
+ * @buf: returned buffer of dump data in format
+ */
+int tipc_sk_dump(struct sock *sk, u16 dqueues, char *buf)
+{
+	int i = 0;
+	size_t sz = (dqueues) ? SK_LMAX : SK_LMIN;
+	struct tipc_sock *tsk;
+	struct publication *p;
+	bool tsk_connected;
+
+	if (!sk) {
+		i += scnprintf(buf, sz, "sk data: (null)\n");
+		return i;
+	}
+
+	tsk = tipc_sk(sk);
+	tsk_connected = !tipc_sk_type_connectionless(sk);
+
+	i += scnprintf(buf, sz, "sk data: %u", sk->sk_type);
+	i += scnprintf(buf + i, sz - i, " %d", sk->sk_state);
+	i += scnprintf(buf + i, sz - i, " %x", tsk_own_node(tsk));
+	i += scnprintf(buf + i, sz - i, " %u", tsk->portid);
+	i += scnprintf(buf + i, sz - i, " | %u", tsk_connected);
+	if (tsk_connected) {
+		i += scnprintf(buf + i, sz - i, " %x", tsk_peer_node(tsk));
+		i += scnprintf(buf + i, sz - i, " %u", tsk_peer_port(tsk));
+		i += scnprintf(buf + i, sz - i, " %u", tsk->conn_type);
+		i += scnprintf(buf + i, sz - i, " %u", tsk->conn_instance);
+	}
+	i += scnprintf(buf + i, sz - i, " | %u", tsk->published);
+	if (tsk->published) {
+		p = list_first_entry_or_null(&tsk->publications,
+					     struct publication, binding_sock);
+		i += scnprintf(buf + i, sz - i, " %u", (p) ? p->type : 0);
+		i += scnprintf(buf + i, sz - i, " %u", (p) ? p->lower : 0);
+		i += scnprintf(buf + i, sz - i, " %u", (p) ? p->upper : 0);
+	}
+	i += scnprintf(buf + i, sz - i, " | %u", tsk->snd_win);
+	i += scnprintf(buf + i, sz - i, " %u", tsk->rcv_win);
+	i += scnprintf(buf + i, sz - i, " %u", tsk->max_pkt);
+	i += scnprintf(buf + i, sz - i, " %x", tsk->peer_caps);
+	i += scnprintf(buf + i, sz - i, " %u", tsk->cong_link_cnt);
+	i += scnprintf(buf + i, sz - i, " %u", tsk->snt_unacked);
+	i += scnprintf(buf + i, sz - i, " %u", tsk->rcv_unacked);
+	i += scnprintf(buf + i, sz - i, " %u", atomic_read(&tsk->dupl_rcvcnt));
+	i += scnprintf(buf + i, sz - i, " %u", sk->sk_shutdown);
+	i += scnprintf(buf + i, sz - i, " | %d", sk_wmem_alloc_get(sk));
+	i += scnprintf(buf + i, sz - i, " %d", sk->sk_sndbuf);
+	i += scnprintf(buf + i, sz - i, " | %d", sk_rmem_alloc_get(sk));
+	i += scnprintf(buf + i, sz - i, " %d", sk->sk_rcvbuf);
+	i += scnprintf(buf + i, sz - i, " | %d\n", READ_ONCE(sk->sk_backlog.len));
+
+	if (dqueues & TIPC_DUMP_SK_SNDQ) {
+		i += scnprintf(buf + i, sz - i, "sk_write_queue: ");
+		i += tipc_list_dump(&sk->sk_write_queue, false, buf + i);
+	}
+
+	if (dqueues & TIPC_DUMP_SK_RCVQ) {
+		i += scnprintf(buf + i, sz - i, "sk_receive_queue: ");
+		i += tipc_list_dump(&sk->sk_receive_queue, false, buf + i);
+	}
+
+	if (dqueues & TIPC_DUMP_SK_BKLGQ) {
+		i += scnprintf(buf + i, sz - i, "sk_backlog:\n  head ");
+		i += tipc_skb_dump(sk->sk_backlog.head, false, buf + i);
+		if (sk->sk_backlog.tail != sk->sk_backlog.head) {
+			i += scnprintf(buf + i, sz - i, "  tail ");
+			i += tipc_skb_dump(sk->sk_backlog.tail, false,
+					   buf + i);
+		}
+	}
+
+	return i;
+}