Initial import

1 files changed, 2837 insertions, 0 deletions

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
new file mode 100644
index 000000000..f485600c4
--- /dev/null
+++ b/net/tipc/socket.c
@@ -0,0 +1,2837 @@
+/*
+ * net/tipc/socket.c: TIPC socket API
+ *
+ * Copyright (c) 2001-2007, 2012-2015, Ericsson AB
+ * Copyright (c) 2004-2008, 2010-2013, Wind River Systems
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/rhashtable.h>
+#include "core.h"
+#include "name_table.h"
+#include "node.h"
+#include "link.h"
+#include "name_distr.h"
+#include "socket.h"
+
+#define SS_LISTENING		-1	/* socket is listening */
+#define SS_READY		-2	/* socket is connectionless */
+
+#define CONN_TIMEOUT_DEFAULT	8000	/* default connect timeout = 8s */
+#define CONN_PROBING_INTERVAL	msecs_to_jiffies(3600000)  /* [ms] => 1 h */
+#define TIPC_FWD_MSG		1
+#define TIPC_CONN_OK		0
+#define TIPC_CONN_PROBING	1
+#define TIPC_MAX_PORT		0xffffffff
+#define TIPC_MIN_PORT		1
+
+/**
+ * struct tipc_sock - TIPC socket structure
+ * @sk: socket - interacts with 'port' and with user via the socket API
+ * @connected: non-zero if port is currently connected to a peer port
+ * @conn_type: TIPC type used when connection was established
+ * @conn_instance: TIPC instance used when connection was established
+ * @published: non-zero if port has one or more associated names
+ * @max_pkt: maximum packet size "hint" used when building messages sent by port
+ * @portid: unique port identity in TIPC socket hash table
+ * @phdr: preformatted message header used when sending messages
+ * @port_list: adjacent ports in TIPC's global list of ports
+ * @publications: list of publications for port
+ * @pub_count: total # of publications port has made during its lifetime
+ * @probing_state:
+ * @probing_intv:
+ * @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
+ * @link_cong: non-zero if owner must sleep because of link congestion
+ * @sent_unacked: # messages sent by socket, and not yet acked by peer
+ * @rcv_unacked: # messages read by user, but not yet acked back to peer
+ * @remote: 'connected' peer for dgram/rdm
+ * @node: hash table node
+ * @rcu: rcu struct for tipc_sock
+ */
+struct tipc_sock {
+	struct sock sk;
+	int connected;
+	u32 conn_type;
+	u32 conn_instance;
+	int published;
+	u32 max_pkt;
+	u32 portid;
+	struct tipc_msg phdr;
+	struct list_head sock_list;
+	struct list_head publications;
+	u32 pub_count;
+	u32 probing_state;
+	unsigned long probing_intv;
+	uint conn_timeout;
+	atomic_t dupl_rcvcnt;
+	bool link_cong;
+	uint sent_unacked;
+	uint rcv_unacked;
+	struct sockaddr_tipc remote;
+	struct rhash_head node;
+	struct rcu_head rcu;
+};
+
+static int tipc_backlog_rcv(struct sock *sk, struct sk_buff *skb);
+static void tipc_data_ready(struct sock *sk);
+static void tipc_write_space(struct sock *sk);
+static int tipc_release(struct socket *sock);
+static int tipc_accept(struct socket *sock, struct socket *new_sock, int flags);
+static int tipc_wait_for_sndmsg(struct socket *sock, long *timeo_p);
+static void tipc_sk_timeout(unsigned long data);
+static int tipc_sk_publish(struct tipc_sock *tsk, uint scope,
+			   struct tipc_name_seq const *seq);
+static int tipc_sk_withdraw(struct tipc_sock *tsk, uint scope,
+			    struct tipc_name_seq const *seq);
+static struct tipc_sock *tipc_sk_lookup(struct net *net, u32 portid);
+static int tipc_sk_insert(struct tipc_sock *tsk);
+static void tipc_sk_remove(struct tipc_sock *tsk);
+static int __tipc_send_stream(struct socket *sock, struct msghdr *m,
+			      size_t dsz);
+static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dsz);
+
+static const struct proto_ops packet_ops;
+static const struct proto_ops stream_ops;
+static const struct proto_ops msg_ops;
+static struct proto tipc_proto;
+
+static const struct nla_policy tipc_nl_sock_policy[TIPC_NLA_SOCK_MAX + 1] = {
+	[TIPC_NLA_SOCK_UNSPEC]		= { .type = NLA_UNSPEC },
+	[TIPC_NLA_SOCK_ADDR]		= { .type = NLA_U32 },
+	[TIPC_NLA_SOCK_REF]		= { .type = NLA_U32 },
+	[TIPC_NLA_SOCK_CON]		= { .type = NLA_NESTED },
+	[TIPC_NLA_SOCK_HAS_PUBL]	= { .type = NLA_FLAG }
+};
+
+static const struct rhashtable_params tsk_rht_params;
+
+/*
+ * Revised TIPC socket locking policy:
+ *
+ * Most socket operations take the standard socket lock when they start
+ * and hold it until they finish (or until they need to sleep).  Acquiring
+ * this lock grants the owner exclusive access to the fields of the socket
+ * data structures, with the exception of the backlog queue.  A few socket
+ * operations can be done without taking the socket lock because they only
+ * read socket information that never changes during the life of the socket.
+ *
+ * Socket operations may acquire the lock for the associated TIPC port if they
+ * need to perform an operation on the port.  If any routine needs to acquire
+ * both the socket lock and the port lock it must take the socket lock first
+ * to avoid the risk of deadlock.
+ *
+ * The dispatcher handling incoming messages cannot grab the socket lock in
+ * the standard fashion, since invoked it runs at the BH level and cannot block.
+ * Instead, it checks to see if the socket lock is currently owned by someone,
+ * and either handles the message itself or adds it to the socket's backlog
+ * queue; in the latter case the queued message is processed once the process
+ * owning the socket lock releases it.
+ *
+ * NOTE: Releasing the socket lock while an operation is sleeping overcomes
+ * the problem of a blocked socket operation preventing any other operations
+ * from occurring.  However, applications must be careful if they have
+ * multiple threads trying to send (or receive) on the same socket, as these
+ * operations might interfere with each other.  For example, doing a connect
+ * and a receive at the same time might allow the receive to consume the
+ * ACK message meant for the connect.  While additional work could be done
+ * to try and overcome this, it doesn't seem to be worthwhile at the present.
+ *
+ * NOTE: Releasing the socket lock while an operation is sleeping also ensures
+ * that another operation that must be performed in a non-blocking manner is
+ * not delayed for very long because the lock has already been taken.
+ *
+ * NOTE: This code assumes that certain fields of a port/socket pair are
+ * constant over its lifetime; such fields can be examined without taking
+ * the socket lock and/or port lock, and do not need to be re-read even
+ * after resuming processing after waiting.  These fields include:
+ *   - socket type
+ *   - pointer to socket sk structure (aka tipc_sock structure)
+ *   - pointer to port structure
+ *   - port reference
+ */
+
+static u32 tsk_own_node(struct tipc_sock *tsk)
+{
+	return msg_prevnode(&tsk->phdr);
+}
+
+static u32 tsk_peer_node(struct tipc_sock *tsk)
+{
+	return msg_destnode(&tsk->phdr);
+}
+
+static u32 tsk_peer_port(struct tipc_sock *tsk)
+{
+	return msg_destport(&tsk->phdr);
+}
+
+static  bool tsk_unreliable(struct tipc_sock *tsk)
+{
+	return msg_src_droppable(&tsk->phdr) != 0;
+}
+
+static void tsk_set_unreliable(struct tipc_sock *tsk, bool unreliable)
+{
+	msg_set_src_droppable(&tsk->phdr, unreliable ? 1 : 0);
+}
+
+static bool tsk_unreturnable(struct tipc_sock *tsk)
+{
+	return msg_dest_droppable(&tsk->phdr) != 0;
+}
+
+static void tsk_set_unreturnable(struct tipc_sock *tsk, bool unreturnable)
+{
+	msg_set_dest_droppable(&tsk->phdr, unreturnable ? 1 : 0);
+}
+
+static int tsk_importance(struct tipc_sock *tsk)
+{
+	return msg_importance(&tsk->phdr);
+}
+
+static int tsk_set_importance(struct tipc_sock *tsk, int imp)
+{
+	if (imp > TIPC_CRITICAL_IMPORTANCE)
+		return -EINVAL;
+	msg_set_importance(&tsk->phdr, (u32)imp);
+	return 0;
+}
+
+static struct tipc_sock *tipc_sk(const struct sock *sk)
+{
+	return container_of(sk, struct tipc_sock, sk);
+}
+
+static int tsk_conn_cong(struct tipc_sock *tsk)
+{
+	return tsk->sent_unacked >= TIPC_FLOWCTRL_WIN;
+}
+
+/**
+ * tsk_advance_rx_queue - discard first buffer in socket receive queue
+ *
+ * Caller must hold socket lock
+ */
+static void tsk_advance_rx_queue(struct sock *sk)
+{
+	kfree_skb(__skb_dequeue(&sk->sk_receive_queue));
+}
+
+/**
+ * tsk_rej_rx_queue - reject all buffers in socket receive queue
+ *
+ * Caller must hold socket lock
+ */
+static void tsk_rej_rx_queue(struct sock *sk)
+{
+	struct sk_buff *skb;
+	u32 dnode;
+	u32 own_node = tsk_own_node(tipc_sk(sk));
+
+	while ((skb = __skb_dequeue(&sk->sk_receive_queue))) {
+		if (tipc_msg_reverse(own_node, skb, &dnode, TIPC_ERR_NO_PORT))
+			tipc_link_xmit_skb(sock_net(sk), skb, dnode, 0);
+	}
+}
+
+/* tsk_peer_msg - verify if message was sent by connected port's peer
+ *
+ * Handles cases where the node's network address has changed from
+ * the default of <0.0.0> to its configured setting.
+ */
+static bool tsk_peer_msg(struct tipc_sock *tsk, struct tipc_msg *msg)
+{
+	struct tipc_net *tn = net_generic(sock_net(&tsk->sk), tipc_net_id);
+	u32 peer_port = tsk_peer_port(tsk);
+	u32 orig_node;
+	u32 peer_node;
+
+	if (unlikely(!tsk->connected))
+		return false;
+
+	if (unlikely(msg_origport(msg) != peer_port))
+		return false;
+
+	orig_node = msg_orignode(msg);
+	peer_node = tsk_peer_node(tsk);
+
+	if (likely(orig_node == peer_node))
+		return true;
+
+	if (!orig_node && (peer_node == tn->own_addr))
+		return true;
+
+	if (!peer_node && (orig_node == tn->own_addr))
+		return true;
+
+	return false;
+}
+
+/**
+ * tipc_sk_create - create a TIPC socket
+ * @net: network namespace (must be default network)
+ * @sock: pre-allocated socket structure
+ * @protocol: protocol indicator (must be 0)
+ * @kern: caused by kernel or by userspace?
+ *
+ * This routine creates additional data structures used by the TIPC socket,
+ * initializes them, and links them together.
+ *
+ * Returns 0 on success, errno otherwise
+ */
+static int tipc_sk_create(struct net *net, struct socket *sock,
+			  int protocol, int kern)
+{
+	struct tipc_net *tn;
+	const struct proto_ops *ops;
+	socket_state state;
+	struct sock *sk;
+	struct tipc_sock *tsk;
+	struct tipc_msg *msg;
+
+	/* Validate arguments */
+	if (unlikely(protocol != 0))
+		return -EPROTONOSUPPORT;
+
+	switch (sock->type) {
+	case SOCK_STREAM:
+		ops = &stream_ops;
+		state = SS_UNCONNECTED;
+		break;
+	case SOCK_SEQPACKET:
+		ops = &packet_ops;
+		state = SS_UNCONNECTED;
+		break;
+	case SOCK_DGRAM:
+	case SOCK_RDM:
+		ops = &msg_ops;
+		state = SS_READY;
+		break;
+	default:
+		return -EPROTOTYPE;
+	}
+
+	/* Allocate socket's protocol area */
+	sk = sk_alloc(net, AF_TIPC, GFP_KERNEL, &tipc_proto);
+	if (sk == NULL)
+		return -ENOMEM;
+
+	tsk = tipc_sk(sk);
+	tsk->max_pkt = MAX_PKT_DEFAULT;
+	INIT_LIST_HEAD(&tsk->publications);
+	msg = &tsk->phdr;
+	tn = net_generic(sock_net(sk), tipc_net_id);
+	tipc_msg_init(tn->own_addr, msg, TIPC_LOW_IMPORTANCE, TIPC_NAMED_MSG,
+		      NAMED_H_SIZE, 0);
+
+	/* Finish initializing socket data structures */
+	sock->ops = ops;
+	sock->state = state;
+	sock_init_data(sock, sk);
+	if (tipc_sk_insert(tsk)) {
+		pr_warn("Socket create failed; port numbrer exhausted\n");
+		return -EINVAL;
+	}
+	msg_set_origport(msg, tsk->portid);
+	setup_timer(&sk->sk_timer, tipc_sk_timeout, (unsigned long)tsk);
+	sk->sk_backlog_rcv = tipc_backlog_rcv;
+	sk->sk_rcvbuf = sysctl_tipc_rmem[1];
+	sk->sk_data_ready = tipc_data_ready;
+	sk->sk_write_space = tipc_write_space;
+	tsk->conn_timeout = CONN_TIMEOUT_DEFAULT;
+	tsk->sent_unacked = 0;
+	atomic_set(&tsk->dupl_rcvcnt, 0);
+
+	if (sock->state == SS_READY) {
+		tsk_set_unreturnable(tsk, true);
+		if (sock->type == SOCK_DGRAM)
+			tsk_set_unreliable(tsk, true);
+	}
+	return 0;
+}
+
+static void tipc_sk_callback(struct rcu_head *head)
+{
+	struct tipc_sock *tsk = container_of(head, struct tipc_sock, rcu);
+
+	sock_put(&tsk->sk);
+}
+
+/**
+ * tipc_release - destroy a TIPC socket
+ * @sock: socket to destroy
+ *
+ * This routine cleans up any messages that are still queued on the socket.
+ * For DGRAM and RDM socket types, all queued messages are rejected.
+ * For SEQPACKET and STREAM socket types, the first message is rejected
+ * and any others are discarded.  (If the first message on a STREAM socket
+ * is partially-read, it is discarded and the next one is rejected instead.)
+ *
+ * NOTE: Rejected messages are not necessarily returned to the sender!  They
+ * are returned or discarded according to the "destination droppable" setting
+ * specified for the message by the sender.
+ *
+ * Returns 0 on success, errno otherwise
+ */
+static int tipc_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+	struct net *net;
+	struct tipc_sock *tsk;
+	struct sk_buff *skb;
+	u32 dnode, probing_state;
+
+	/*
+	 * Exit if socket isn't fully initialized (occurs when a failed accept()
+	 * releases a pre-allocated child socket that was never used)
+	 */
+	if (sk == NULL)
+		return 0;
+
+	net = sock_net(sk);
+	tsk = tipc_sk(sk);
+	lock_sock(sk);
+
+	/*
+	 * Reject all unreceived messages, except on an active connection
+	 * (which disconnects locally & sends a 'FIN+' to peer)
+	 */
+	dnode = tsk_peer_node(tsk);
+	while (sock->state != SS_DISCONNECTING) {
+		skb = __skb_dequeue(&sk->sk_receive_queue);
+		if (skb == NULL)
+			break;
+		if (TIPC_SKB_CB(skb)->handle != NULL)
+			kfree_skb(skb);
+		else {
+			if ((sock->state == SS_CONNECTING) ||
+			    (sock->state == SS_CONNECTED)) {
+				sock->state = SS_DISCONNECTING;
+				tsk->connected = 0;
+				tipc_node_remove_conn(net, dnode, tsk->portid);
+			}
+			if (tipc_msg_reverse(tsk_own_node(tsk), skb, &dnode,
+					     TIPC_ERR_NO_PORT))
+				tipc_link_xmit_skb(net, skb, dnode, 0);
+		}
+	}
+
+	tipc_sk_withdraw(tsk, 0, NULL);
+	probing_state = tsk->probing_state;
+	if (del_timer_sync(&sk->sk_timer) &&
+	    probing_state != TIPC_CONN_PROBING)
+		sock_put(sk);
+	tipc_sk_remove(tsk);
+	if (tsk->connected) {
+		skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE,
+				      TIPC_CONN_MSG, SHORT_H_SIZE, 0, dnode,
+				      tsk_own_node(tsk), tsk_peer_port(tsk),
+				      tsk->portid, TIPC_ERR_NO_PORT);
+		if (skb)
+			tipc_link_xmit_skb(net, skb, dnode, tsk->portid);
+		tipc_node_remove_conn(net, dnode, tsk->portid);
+	}
+
+	/* Discard any remaining (connection-based) messages in receive queue */
+	__skb_queue_purge(&sk->sk_receive_queue);
+
+	/* Reject any messages that accumulated in backlog queue */
+	sock->state = SS_DISCONNECTING;
+	release_sock(sk);
+
+	call_rcu(&tsk->rcu, tipc_sk_callback);
+	sock->sk = NULL;
+
+	return 0;
+}
+
+/**
+ * tipc_bind - associate or disassocate TIPC name(s) with a socket
+ * @sock: socket structure
+ * @uaddr: socket address describing name(s) and desired operation
+ * @uaddr_len: size of socket address data structure
+ *
+ * Name and name sequence binding is indicated using a positive scope value;
+ * a negative scope value unbinds the specified name.  Specifying no name
+ * (i.e. a socket address length of 0) unbinds all names from the socket.
+ *
+ * Returns 0 on success, errno otherwise
+ *
+ * NOTE: This routine doesn't need to take the socket lock since it doesn't
+ *       access any non-constant socket information.
+ */
+static int tipc_bind(struct socket *sock, struct sockaddr *uaddr,
+		     int uaddr_len)
+{
+	struct sock *sk = sock->sk;
+	struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr;
+	struct tipc_sock *tsk = tipc_sk(sk);
+	int res = -EINVAL;
+
+	lock_sock(sk);
+	if (unlikely(!uaddr_len)) {
+		res = tipc_sk_withdraw(tsk, 0, NULL);
+		goto exit;
+	}
+
+	if (uaddr_len < sizeof(struct sockaddr_tipc)) {
+		res = -EINVAL;
+		goto exit;
+	}
+	if (addr->family != AF_TIPC) {
+		res = -EAFNOSUPPORT;
+		goto exit;
+	}
+
+	if (addr->addrtype == TIPC_ADDR_NAME)
+		addr->addr.nameseq.upper = addr->addr.nameseq.lower;
+	else if (addr->addrtype != TIPC_ADDR_NAMESEQ) {
+		res = -EAFNOSUPPORT;
+		goto exit;
+	}
+
+	if ((addr->addr.nameseq.type < TIPC_RESERVED_TYPES) &&
+	    (addr->addr.nameseq.type != TIPC_TOP_SRV) &&
+	    (addr->addr.nameseq.type != TIPC_CFG_SRV)) {
+		res = -EACCES;
+		goto exit;
+	}
+
+	res = (addr->scope > 0) ?
+		tipc_sk_publish(tsk, addr->scope, &addr->addr.nameseq) :
+		tipc_sk_withdraw(tsk, -addr->scope, &addr->addr.nameseq);
+exit:
+	release_sock(sk);
+	return res;
+}
+
+/**
+ * tipc_getname - get port ID of socket or peer socket
+ * @sock: socket structure
+ * @uaddr: area for returned socket address
+ * @uaddr_len: area for returned length of socket address
+ * @peer: 0 = own ID, 1 = current peer ID, 2 = current/former peer ID
+ *
+ * Returns 0 on success, errno otherwise
+ *
+ * NOTE: This routine doesn't need to take the socket lock since it only
+ *       accesses socket information that is unchanging (or which changes in
+ *       a completely predictable manner).
+ */
+static int tipc_getname(struct socket *sock, struct sockaddr *uaddr,
+			int *uaddr_len, int peer)
+{
+	struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr;
+	struct tipc_sock *tsk = tipc_sk(sock->sk);
+	struct tipc_net *tn = net_generic(sock_net(sock->sk), tipc_net_id);
+
+	memset(addr, 0, sizeof(*addr));
+	if (peer) {
+		if ((sock->state != SS_CONNECTED) &&
+			((peer != 2) || (sock->state != SS_DISCONNECTING)))
+			return -ENOTCONN;
+		addr->addr.id.ref = tsk_peer_port(tsk);
+		addr->addr.id.node = tsk_peer_node(tsk);
+	} else {
+		addr->addr.id.ref = tsk->portid;
+		addr->addr.id.node = tn->own_addr;
+	}
+
+	*uaddr_len = sizeof(*addr);
+	addr->addrtype = TIPC_ADDR_ID;
+	addr->family = AF_TIPC;
+	addr->scope = 0;
+	addr->addr.name.domain = 0;
+
+	return 0;
+}
+
+/**
+ * tipc_poll - read and possibly block on pollmask
+ * @file: file structure associated with the socket
+ * @sock: socket for which to calculate the poll bits
+ * @wait: ???
+ *
+ * Returns pollmask value
+ *
+ * COMMENTARY:
+ * It appears that the usual socket locking mechanisms are not useful here
+ * since the pollmask info is potentially out-of-date the moment this routine
+ * exits.  TCP and other protocols seem to rely on higher level poll routines
+ * to handle any preventable race conditions, so TIPC will do the same ...
+ *
+ * TIPC sets the returned events as follows:
+ *
+ * socket state		flags set
+ * ------------		---------
+ * unconnected		no read flags
+ *			POLLOUT if port is not congested
+ *
+ * connecting		POLLIN/POLLRDNORM if ACK/NACK in rx queue
+ *			no write flags
+ *
+ * connected		POLLIN/POLLRDNORM if data in rx queue
+ *			POLLOUT if port is not congested
+ *
+ * disconnecting	POLLIN/POLLRDNORM/POLLHUP
+ *			no write flags
+ *
+ * listening		POLLIN if SYN in rx queue
+ *			no write flags
+ *
+ * ready		POLLIN/POLLRDNORM if data in rx queue
+ * [connectionless]	POLLOUT (since port cannot be congested)
+ *
+ * IMPORTANT: The fact that a read or write operation is indicated does NOT
+ * imply that the operation will succeed, merely that it should be performed
+ * and will not block.
+ */
+static unsigned int tipc_poll(struct file *file, struct socket *sock,
+			      poll_table *wait)
+{
+	struct sock *sk = sock->sk;
+	struct tipc_sock *tsk = tipc_sk(sk);
+	u32 mask = 0;
+
+	sock_poll_wait(file, sk_sleep(sk), wait);
+
+	switch ((int)sock->state) {
+	case SS_UNCONNECTED:
+		if (!tsk->link_cong)
+			mask |= POLLOUT;
+		break;
+	case SS_READY:
+	case SS_CONNECTED:
+		if (!tsk->link_cong && !tsk_conn_cong(tsk))
+			mask |= POLLOUT;
+		/* fall thru' */
+	case SS_CONNECTING:
+	case SS_LISTENING:
+		if (!skb_queue_empty(&sk->sk_receive_queue))
+			mask |= (POLLIN | POLLRDNORM);
+		break;
+	case SS_DISCONNECTING:
+		mask = (POLLIN | POLLRDNORM | POLLHUP);
+		break;
+	}
+
+	return mask;
+}
+
+/**
+ * tipc_sendmcast - send multicast message
+ * @sock: socket structure
+ * @seq: destination address
+ * @msg: message to send
+ * @dsz: total length of message data
+ * @timeo: timeout to wait for wakeup
+ *
+ * Called from function tipc_sendmsg(), which has done all sanity checks
+ * Returns the number of bytes sent on success, or errno
+ */
+static int tipc_sendmcast(struct  socket *sock, struct tipc_name_seq *seq,
+			  struct msghdr *msg, size_t dsz, long timeo)
+{
+	struct sock *sk = sock->sk;
+	struct tipc_sock *tsk = tipc_sk(sk);
+	struct net *net = sock_net(sk);
+	struct tipc_msg *mhdr = &tsk->phdr;
+	struct sk_buff_head *pktchain = &sk->sk_write_queue;
+	struct iov_iter save = msg->msg_iter;
+	uint mtu;
+	int rc;
+
+	msg_set_type(mhdr, TIPC_MCAST_MSG);
+	msg_set_lookup_scope(mhdr, TIPC_CLUSTER_SCOPE);
+	msg_set_destport(mhdr, 0);
+	msg_set_destnode(mhdr, 0);
+	msg_set_nametype(mhdr, seq->type);
+	msg_set_namelower(mhdr, seq->lower);
+	msg_set_nameupper(mhdr, seq->upper);
+	msg_set_hdr_sz(mhdr, MCAST_H_SIZE);
+
+new_mtu:
+	mtu = tipc_bclink_get_mtu();
+	rc = tipc_msg_build(mhdr, msg, 0, dsz, mtu, pktchain);
+	if (unlikely(rc < 0))
+		return rc;
+
+	do {
+		rc = tipc_bclink_xmit(net, pktchain);
+		if (likely(rc >= 0)) {
+			rc = dsz;
+			break;
+		}
+		if (rc == -EMSGSIZE) {
+			msg->msg_iter = save;
+			goto new_mtu;
+		}
+		if (rc != -ELINKCONG)
+			break;
+		tipc_sk(sk)->link_cong = 1;
+		rc = tipc_wait_for_sndmsg(sock, &timeo);
+		if (rc)
+			__skb_queue_purge(pktchain);
+	} while (!rc);
+	return rc;
+}
+
+/**
+ * tipc_sk_mcast_rcv - Deliver multicast messages to all destination sockets
+ * @arrvq: queue with arriving messages, to be cloned after destination lookup
+ * @inputq: queue with cloned messages, delivered to socket after dest lookup
+ *
+ * Multi-threaded: parallel calls with reference to same queues may occur
+ */
+void tipc_sk_mcast_rcv(struct net *net, struct sk_buff_head *arrvq,
+		       struct sk_buff_head *inputq)
+{
+	struct tipc_msg *msg;
+	struct tipc_plist dports;
+	u32 portid;
+	u32 scope = TIPC_CLUSTER_SCOPE;
+	struct sk_buff_head tmpq;
+	uint hsz;
+	struct sk_buff *skb, *_skb;
+
+	__skb_queue_head_init(&tmpq);
+	tipc_plist_init(&dports);
+
+	skb = tipc_skb_peek(arrvq, &inputq->lock);
+	for (; skb; skb = tipc_skb_peek(arrvq, &inputq->lock)) {
+		msg = buf_msg(skb);
+		hsz = skb_headroom(skb) + msg_hdr_sz(msg);
+
+		if (in_own_node(net, msg_orignode(msg)))
+			scope = TIPC_NODE_SCOPE;
+
+		/* Create destination port list and message clones: */
+		tipc_nametbl_mc_translate(net,
+					  msg_nametype(msg), msg_namelower(msg),
+					  msg_nameupper(msg), scope, &dports);
+		portid = tipc_plist_pop(&dports);
+		for (; portid; portid = tipc_plist_pop(&dports)) {
+			_skb = __pskb_copy(skb, hsz, GFP_ATOMIC);
+			if (_skb) {
+				msg_set_destport(buf_msg(_skb), portid);
+				__skb_queue_tail(&tmpq, _skb);
+				continue;
+			}
+			pr_warn("Failed to clone mcast rcv buffer\n");
+		}
+		/* Append to inputq if not already done by other thread */
+		spin_lock_bh(&inputq->lock);
+		if (skb_peek(arrvq) == skb) {
+			skb_queue_splice_tail_init(&tmpq, inputq);
+			kfree_skb(__skb_dequeue(arrvq));
+		}
+		spin_unlock_bh(&inputq->lock);
+		__skb_queue_purge(&tmpq);
+		kfree_skb(skb);
+	}
+	tipc_sk_rcv(net, inputq);
+}
+
+/**
+ * tipc_sk_proto_rcv - receive a connection mng protocol message
+ * @tsk: receiving socket
+ * @skb: pointer to message buffer. Set to NULL if buffer is consumed.
+ */
+static void tipc_sk_proto_rcv(struct tipc_sock *tsk, struct sk_buff **skb)
+{
+	struct tipc_msg *msg = buf_msg(*skb);
+	int conn_cong;
+	u32 dnode;
+	u32 own_node = tsk_own_node(tsk);
+	/* Ignore if connection cannot be validated: */
+	if (!tsk_peer_msg(tsk, msg))
+		goto exit;
+
+	tsk->probing_state = TIPC_CONN_OK;
+
+	if (msg_type(msg) == CONN_ACK) {
+		conn_cong = tsk_conn_cong(tsk);
+		tsk->sent_unacked -= msg_msgcnt(msg);
+		if (conn_cong)
+			tsk->sk.sk_write_space(&tsk->sk);
+	} else if (msg_type(msg) == CONN_PROBE) {
+		if (tipc_msg_reverse(own_node, *skb, &dnode, TIPC_OK)) {
+			msg_set_type(msg, CONN_PROBE_REPLY);
+			return;
+		}
+	}
+	/* Do nothing if msg_type() == CONN_PROBE_REPLY */
+exit:
+	kfree_skb(*skb);
+	*skb = NULL;
+}
+
+static int tipc_wait_for_sndmsg(struct socket *sock, long *timeo_p)
+{
+	struct sock *sk = sock->sk;
+	struct tipc_sock *tsk = tipc_sk(sk);
+	DEFINE_WAIT(wait);
+	int done;
+
+	do {
+		int err = sock_error(sk);
+		if (err)
+			return err;
+		if (sock->state == SS_DISCONNECTING)
+			return -EPIPE;
+		if (!*timeo_p)
+			return -EAGAIN;
+		if (signal_pending(current))
+			return sock_intr_errno(*timeo_p);
+
+		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+		done = sk_wait_event(sk, timeo_p, !tsk->link_cong);
+		finish_wait(sk_sleep(sk), &wait);
+	} while (!done);
+	return 0;
+}
+
+/**
+ * tipc_sendmsg - send message in connectionless manner
+ * @sock: socket structure
+ * @m: message to send
+ * @dsz: amount of user data to be sent
+ *
+ * Message must have an destination specified explicitly.
+ * Used for SOCK_RDM and SOCK_DGRAM messages,
+ * and for 'SYN' messages on SOCK_SEQPACKET and SOCK_STREAM connections.
+ * (Note: 'SYN+' is prohibited on SOCK_STREAM.)
+ *
+ * Returns the number of bytes sent on success, or errno otherwise
+ */
+static int tipc_sendmsg(struct socket *sock,
+			struct msghdr *m, size_t dsz)
+{
+	struct sock *sk = sock->sk;
+	int ret;
+
+	lock_sock(sk);
+	ret = __tipc_sendmsg(sock, m, dsz);
+	release_sock(sk);
+
+	return ret;
+}
+
+static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dsz)
+{
+	DECLARE_SOCKADDR(struct sockaddr_tipc *, dest, m->msg_name);
+	struct sock *sk = sock->sk;
+	struct tipc_sock *tsk = tipc_sk(sk);
+	struct net *net = sock_net(sk);
+	struct tipc_msg *mhdr = &tsk->phdr;
+	u32 dnode, dport;
+	struct sk_buff_head *pktchain = &sk->sk_write_queue;
+	struct sk_buff *skb;
+	struct tipc_name_seq *seq;
+	struct iov_iter save;
+	u32 mtu;
+	long timeo;
+	int rc;
+
+	if (dsz > TIPC_MAX_USER_MSG_SIZE)
+		return -EMSGSIZE;
+	if (unlikely(!dest)) {
+		if (tsk->connected && sock->state == SS_READY)
+			dest = &tsk->remote;
+		else
+			return -EDESTADDRREQ;
+	} else if (unlikely(m->msg_namelen < sizeof(*dest)) ||
+		   dest->family != AF_TIPC) {
+		return -EINVAL;
+	}
+	if (unlikely(sock->state != SS_READY)) {
+		if (sock->state == SS_LISTENING)
+			return -EPIPE;
+		if (sock->state != SS_UNCONNECTED)
+			return -EISCONN;
+		if (tsk->published)
+			return -EOPNOTSUPP;
+		if (dest->addrtype == TIPC_ADDR_NAME) {
+			tsk->conn_type = dest->addr.name.name.type;
+			tsk->conn_instance = dest->addr.name.name.instance;
+		}
+	}
+	seq = &dest->addr.nameseq;
+	timeo = sock_sndtimeo(sk, m->msg_flags & MSG_DONTWAIT);
+
+	if (dest->addrtype == TIPC_ADDR_MCAST) {
+		return tipc_sendmcast(sock, seq, m, dsz, timeo);
+	} else if (dest->addrtype == TIPC_ADDR_NAME) {
+		u32 type = dest->addr.name.name.type;
+		u32 inst = dest->addr.name.name.instance;
+		u32 domain = dest->addr.name.domain;
+
+		dnode = domain;
+		msg_set_type(mhdr, TIPC_NAMED_MSG);
+		msg_set_hdr_sz(mhdr, NAMED_H_SIZE);
+		msg_set_nametype(mhdr, type);
+		msg_set_nameinst(mhdr, inst);
+		msg_set_lookup_scope(mhdr, tipc_addr_scope(domain));
+		dport = tipc_nametbl_translate(net, type, inst, &dnode);
+		msg_set_destnode(mhdr, dnode);
+		msg_set_destport(mhdr, dport);
+		if (unlikely(!dport && !dnode))
+			return -EHOSTUNREACH;
+	} else if (dest->addrtype == TIPC_ADDR_ID) {
+		dnode = dest->addr.id.node;
+		msg_set_type(mhdr, TIPC_DIRECT_MSG);
+		msg_set_lookup_scope(mhdr, 0);
+		msg_set_destnode(mhdr, dnode);
+		msg_set_destport(mhdr, dest->addr.id.ref);
+		msg_set_hdr_sz(mhdr, BASIC_H_SIZE);
+	}
+
+	save = m->msg_iter;
+new_mtu:
+	mtu = tipc_node_get_mtu(net, dnode, tsk->portid);
+	rc = tipc_msg_build(mhdr, m, 0, dsz, mtu, pktchain);
+	if (rc < 0)
+		return rc;
+
+	do {
+		skb = skb_peek(pktchain);
+		TIPC_SKB_CB(skb)->wakeup_pending = tsk->link_cong;
+		rc = tipc_link_xmit(net, pktchain, dnode, tsk->portid);
+		if (likely(rc >= 0)) {
+			if (sock->state != SS_READY)
+				sock->state = SS_CONNECTING;
+			rc = dsz;
+			break;
+		}
+		if (rc == -EMSGSIZE) {
+			m->msg_iter = save;
+			goto new_mtu;
+		}
+		if (rc != -ELINKCONG)
+			break;
+		tsk->link_cong = 1;
+		rc = tipc_wait_for_sndmsg(sock, &timeo);
+		if (rc)
+			__skb_queue_purge(pktchain);
+	} while (!rc);
+
+	return rc;
+}
+
+static int tipc_wait_for_sndpkt(struct socket *sock, long *timeo_p)
+{
+	struct sock *sk = sock->sk;
+	struct tipc_sock *tsk = tipc_sk(sk);
+	DEFINE_WAIT(wait);
+	int done;
+
+	do {
+		int err = sock_error(sk);
+		if (err)
+			return err;
+		if (sock->state == SS_DISCONNECTING)
+			return -EPIPE;
+		else if (sock->state != SS_CONNECTED)
+			return -ENOTCONN;
+		if (!*timeo_p)
+			return -EAGAIN;
+		if (signal_pending(current))
+			return sock_intr_errno(*timeo_p);
+
+		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+		done = sk_wait_event(sk, timeo_p,
+				     (!tsk->link_cong &&
+				      !tsk_conn_cong(tsk)) ||
+				     !tsk->connected);
+		finish_wait(sk_sleep(sk), &wait);
+	} while (!done);
+	return 0;
+}
+
+/**
+ * tipc_send_stream - send stream-oriented data
+ * @sock: socket structure
+ * @m: data to send
+ * @dsz: total length of data to be transmitted
+ *
+ * Used for SOCK_STREAM data.
+ *
+ * Returns the number of bytes sent on success (or partial success),
+ * or errno if no data sent
+ */
+static int tipc_send_stream(struct socket *sock, struct msghdr *m, size_t dsz)
+{
+	struct sock *sk = sock->sk;
+	int ret;
+
+	lock_sock(sk);
+	ret = __tipc_send_stream(sock, m, dsz);
+	release_sock(sk);
+
+	return ret;
+}
+
+static int __tipc_send_stream(struct socket *sock, struct msghdr *m, size_t dsz)
+{
+	struct sock *sk = sock->sk;
+	struct net *net = sock_net(sk);
+	struct tipc_sock *tsk = tipc_sk(sk);
+	struct tipc_msg *mhdr = &tsk->phdr;
+	struct sk_buff_head *pktchain = &sk->sk_write_queue;
+	DECLARE_SOCKADDR(struct sockaddr_tipc *, dest, m->msg_name);
+	u32 portid = tsk->portid;
+	int rc = -EINVAL;
+	long timeo;
+	u32 dnode;
+	uint mtu, send, sent = 0;
+	struct iov_iter save;
+
+	/* Handle implied connection establishment */
+	if (unlikely(dest)) {
+		rc = __tipc_sendmsg(sock, m, dsz);
+		if (dsz && (dsz == rc))
+			tsk->sent_unacked = 1;
+		return rc;
+	}
+	if (dsz > (uint)INT_MAX)
+		return -EMSGSIZE;
+
+	if (unlikely(sock->state != SS_CONNECTED)) {
+		if (sock->state == SS_DISCONNECTING)
+			return -EPIPE;
+		else
+			return -ENOTCONN;
+	}
+
+	timeo = sock_sndtimeo(sk, m->msg_flags & MSG_DONTWAIT);
+	dnode = tsk_peer_node(tsk);
+
+next:
+	save = m->msg_iter;
+	mtu = tsk->max_pkt;
+	send = min_t(uint, dsz - sent, TIPC_MAX_USER_MSG_SIZE);
+	rc = tipc_msg_build(mhdr, m, sent, send, mtu, pktchain);
+	if (unlikely(rc < 0))
+		return rc;
+	do {
+		if (likely(!tsk_conn_cong(tsk))) {
+			rc = tipc_link_xmit(net, pktchain, dnode, portid);
+			if (likely(!rc)) {
+				tsk->sent_unacked++;
+				sent += send;
+				if (sent == dsz)
+					break;
+				goto next;
+			}
+			if (rc == -EMSGSIZE) {
+				tsk->max_pkt = tipc_node_get_mtu(net, dnode,
+								 portid);
+				m->msg_iter = save;
+				goto next;
+			}
+			if (rc != -ELINKCONG)
+				break;
+			tsk->link_cong = 1;
+		}
+		rc = tipc_wait_for_sndpkt(sock, &timeo);
+		if (rc)
+			__skb_queue_purge(pktchain);
+	} while (!rc);
+
+	return sent ? sent : rc;
+}
+
+/**
+ * tipc_send_packet - send a connection-oriented message
+ * @sock: socket structure
+ * @m: message to send
+ * @dsz: length of data to be transmitted
+ *
+ * Used for SOCK_SEQPACKET messages.
+ *
+ * Returns the number of bytes sent on success, or errno otherwise
+ */
+static int tipc_send_packet(struct socket *sock, struct msghdr *m, size_t dsz)
+{
+	if (dsz > TIPC_MAX_USER_MSG_SIZE)
+		return -EMSGSIZE;
+
+	return tipc_send_stream(sock, m, dsz);
+}
+
+/* tipc_sk_finish_conn - complete the setup of a connection
+ */
+static void tipc_sk_finish_conn(struct tipc_sock *tsk, u32 peer_port,
+				u32 peer_node)
+{
+	struct sock *sk = &tsk->sk;
+	struct net *net = sock_net(sk);
+	struct tipc_msg *msg = &tsk->phdr;
+
+	msg_set_destnode(msg, peer_node);
+	msg_set_destport(msg, peer_port);
+	msg_set_type(msg, TIPC_CONN_MSG);
+	msg_set_lookup_scope(msg, 0);
+	msg_set_hdr_sz(msg, SHORT_H_SIZE);
+
+	tsk->probing_intv = CONN_PROBING_INTERVAL;
+	tsk->probing_state = TIPC_CONN_OK;
+	tsk->connected = 1;
+	sk_reset_timer(sk, &sk->sk_timer, jiffies + tsk->probing_intv);
+	tipc_node_add_conn(net, peer_node, tsk->portid, peer_port);
+	tsk->max_pkt = tipc_node_get_mtu(net, peer_node, tsk->portid);
+}
+
+/**
+ * set_orig_addr - capture sender's address for received message
+ * @m: descriptor for message info
+ * @msg: received message header
+ *
+ * Note: Address is not captured if not requested by receiver.
+ */
+static void set_orig_addr(struct msghdr *m, struct tipc_msg *msg)
+{
+	DECLARE_SOCKADDR(struct sockaddr_tipc *, addr, m->msg_name);
+
+	if (addr) {
+		addr->family = AF_TIPC;
+		addr->addrtype = TIPC_ADDR_ID;
+		memset(&addr->addr, 0, sizeof(addr->addr));
+		addr->addr.id.ref = msg_origport(msg);
+		addr->addr.id.node = msg_orignode(msg);
+		addr->addr.name.domain = 0;	/* could leave uninitialized */
+		addr->scope = 0;		/* could leave uninitialized */
+		m->msg_namelen = sizeof(struct sockaddr_tipc);
+	}
+}
+
+/**
+ * tipc_sk_anc_data_recv - optionally capture ancillary data for received message
+ * @m: descriptor for message info
+ * @msg: received message header
+ * @tsk: TIPC port associated with message
+ *
+ * Note: Ancillary data is not captured if not requested by receiver.
+ *
+ * Returns 0 if successful, otherwise errno
+ */
+static int tipc_sk_anc_data_recv(struct msghdr *m, struct tipc_msg *msg,
+				 struct tipc_sock *tsk)
+{
+	u32 anc_data[3];
+	u32 err;
+	u32 dest_type;
+	int has_name;
+	int res;
+
+	if (likely(m->msg_controllen == 0))
+		return 0;
+
+	/* Optionally capture errored message object(s) */
+	err = msg ? msg_errcode(msg) : 0;
+	if (unlikely(err)) {
+		anc_data[0] = err;
+		anc_data[1] = msg_data_sz(msg);
+		res = put_cmsg(m, SOL_TIPC, TIPC_ERRINFO, 8, anc_data);
+		if (res)
+			return res;
+		if (anc_data[1]) {
+			res = put_cmsg(m, SOL_TIPC, TIPC_RETDATA, anc_data[1],
+				       msg_data(msg));
+			if (res)
+				return res;
+		}
+	}
+
+	/* Optionally capture message destination object */
+	dest_type = msg ? msg_type(msg) : TIPC_DIRECT_MSG;
+	switch (dest_type) {
+	case TIPC_NAMED_MSG:
+		has_name = 1;
+		anc_data[0] = msg_nametype(msg);
+		anc_data[1] = msg_namelower(msg);
+		anc_data[2] = msg_namelower(msg);
+		break;
+	case TIPC_MCAST_MSG:
+		has_name = 1;
+		anc_data[0] = msg_nametype(msg);
+		anc_data[1] = msg_namelower(msg);
+		anc_data[2] = msg_nameupper(msg);
+		break;
+	case TIPC_CONN_MSG:
+		has_name = (tsk->conn_type != 0);
+		anc_data[0] = tsk->conn_type;
+		anc_data[1] = tsk->conn_instance;
+		anc_data[2] = tsk->conn_instance;
+		break;
+	default:
+		has_name = 0;
+	}
+	if (has_name) {
+		res = put_cmsg(m, SOL_TIPC, TIPC_DESTNAME, 12, anc_data);
+		if (res)
+			return res;
+	}
+
+	return 0;
+}
+
+static void tipc_sk_send_ack(struct tipc_sock *tsk, uint ack)
+{
+	struct net *net = sock_net(&tsk->sk);
+	struct sk_buff *skb = NULL;
+	struct tipc_msg *msg;
+	u32 peer_port = tsk_peer_port(tsk);
+	u32 dnode = tsk_peer_node(tsk);
+
+	if (!tsk->connected)
+		return;
+	skb = tipc_msg_create(CONN_MANAGER, CONN_ACK, INT_H_SIZE, 0,
+			      dnode, tsk_own_node(tsk), peer_port,
+			      tsk->portid, TIPC_OK);
+	if (!skb)
+		return;
+	msg = buf_msg(skb);
+	msg_set_msgcnt(msg, ack);
+	tipc_link_xmit_skb(net, skb, dnode, msg_link_selector(msg));
+}
+
+static int tipc_wait_for_rcvmsg(struct socket *sock, long *timeop)
+{
+	struct sock *sk = sock->sk;
+	DEFINE_WAIT(wait);
+	long timeo = *timeop;
+	int err;
+
+	for (;;) {
+		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+		if (timeo && skb_queue_empty(&sk->sk_receive_queue)) {
+			if (sock->state == SS_DISCONNECTING) {
+				err = -ENOTCONN;
+				break;
+			}
+			release_sock(sk);
+			timeo = schedule_timeout(timeo);
+			lock_sock(sk);
+		}
+		err = 0;
+		if (!skb_queue_empty(&sk->sk_receive_queue))
+			break;
+		err = -EAGAIN;
+		if (!timeo)
+			break;
+		err = sock_intr_errno(timeo);
+		if (signal_pending(current))
+			break;
+	}
+	finish_wait(sk_sleep(sk), &wait);
+	*timeop = timeo;
+	return err;
+}
+
+/**
+ * tipc_recvmsg - receive packet-oriented message
+ * @m: descriptor for message info
+ * @buf_len: total size of user buffer area
+ * @flags: receive flags
+ *
+ * Used for SOCK_DGRAM, SOCK_RDM, and SOCK_SEQPACKET messages.
+ * If the complete message doesn't fit in user area, truncate it.
+ *
+ * Returns size of returned message data, errno otherwise
+ */
+static int tipc_recvmsg(struct socket *sock, struct msghdr *m, size_t buf_len,
+			int flags)
+{
+	struct sock *sk = sock->sk;
+	struct tipc_sock *tsk = tipc_sk(sk);
+	struct sk_buff *buf;
+	struct tipc_msg *msg;
+	long timeo;
+	unsigned int sz;
+	u32 err;
+	int res;
+
+	/* Catch invalid receive requests */
+	if (unlikely(!buf_len))
+		return -EINVAL;
+
+	lock_sock(sk);
+
+	if (unlikely(sock->state == SS_UNCONNECTED)) {
+		res = -ENOTCONN;
+		goto exit;
+	}
+
+	timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
+restart:
+
+	/* Look for a message in receive queue; wait if necessary */
+	res = tipc_wait_for_rcvmsg(sock, &timeo);
+	if (res)
+		goto exit;
+
+	/* Look at first message in receive queue */
+	buf = skb_peek(&sk->sk_receive_queue);
+	msg = buf_msg(buf);
+	sz = msg_data_sz(msg);
+	err = msg_errcode(msg);
+
+	/* Discard an empty non-errored message & try again */
+	if ((!sz) && (!err)) {
+		tsk_advance_rx_queue(sk);
+		goto restart;
+	}
+
+	/* Capture sender's address (optional) */
+	set_orig_addr(m, msg);
+
+	/* Capture ancillary data (optional) */
+	res = tipc_sk_anc_data_recv(m, msg, tsk);
+	if (res)
+		goto exit;
+
+	/* Capture message data (if valid) & compute return value (always) */
+	if (!err) {
+		if (unlikely(buf_len < sz)) {
+			sz = buf_len;
+			m->msg_flags |= MSG_TRUNC;
+		}
+		res = skb_copy_datagram_msg(buf, msg_hdr_sz(msg), m, sz);
+		if (res)
+			goto exit;
+		res = sz;
+	} else {
+		if ((sock->state == SS_READY) ||
+		    ((err == TIPC_CONN_SHUTDOWN) || m->msg_control))
+			res = 0;
+		else
+			res = -ECONNRESET;
+	}
+
+	/* Consume received message (optional) */
+	if (likely(!(flags & MSG_PEEK))) {
+		if ((sock->state != SS_READY) &&
+		    (++tsk->rcv_unacked >= TIPC_CONNACK_INTV)) {
+			tipc_sk_send_ack(tsk, tsk->rcv_unacked);
+			tsk->rcv_unacked = 0;
+		}
+		tsk_advance_rx_queue(sk);
+	}
+exit:
+	release_sock(sk);
+	return res;
+}
+
+/**
+ * tipc_recv_stream - receive stream-oriented data
+ * @m: descriptor for message info
+ * @buf_len: total size of user buffer area
+ * @flags: receive flags
+ *
+ * Used for SOCK_STREAM messages only.  If not enough data is available
+ * will optionally wait for more; never truncates data.
+ *
+ * Returns size of returned message data, errno otherwise
+ */
+static int tipc_recv_stream(struct socket *sock, struct msghdr *m,
+			    size_t buf_len, int flags)
+{
+	struct sock *sk = sock->sk;
+	struct tipc_sock *tsk = tipc_sk(sk);
+	struct sk_buff *buf;
+	struct tipc_msg *msg;
+	long timeo;
+	unsigned int sz;
+	int sz_to_copy, target, needed;
+	int sz_copied = 0;
+	u32 err;
+	int res = 0;
+
+	/* Catch invalid receive attempts */
+	if (unlikely(!buf_len))
+		return -EINVAL;
+
+	lock_sock(sk);
+
+	if (unlikely(sock->state == SS_UNCONNECTED)) {
+		res = -ENOTCONN;
+		goto exit;
+	}
+
+	target = sock_rcvlowat(sk, flags & MSG_WAITALL, buf_len);
+	timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
+
+restart:
+	/* Look for a message in receive queue; wait if necessary */
+	res = tipc_wait_for_rcvmsg(sock, &timeo);
+	if (res)
+		goto exit;
+
+	/* Look at first message in receive queue */
+	buf = skb_peek(&sk->sk_receive_queue);
+	msg = buf_msg(buf);
+	sz = msg_data_sz(msg);
+	err = msg_errcode(msg);
+
+	/* Discard an empty non-errored message & try again */
+	if ((!sz) && (!err)) {
+		tsk_advance_rx_queue(sk);
+		goto restart;
+	}
+
+	/* Optionally capture sender's address & ancillary data of first msg */
+	if (sz_copied == 0) {
+		set_orig_addr(m, msg);
+		res = tipc_sk_anc_data_recv(m, msg, tsk);
+		if (res)
+			goto exit;
+	}
+
+	/* Capture message data (if valid) & compute return value (always) */
+	if (!err) {
+		u32 offset = (u32)(unsigned long)(TIPC_SKB_CB(buf)->handle);
+
+		sz -= offset;
+		needed = (buf_len - sz_copied);
+		sz_to_copy = (sz <= needed) ? sz : needed;
+
+		res = skb_copy_datagram_msg(buf, msg_hdr_sz(msg) + offset,
+					    m, sz_to_copy);
+		if (res)
+			goto exit;
+
+		sz_copied += sz_to_copy;
+
+		if (sz_to_copy < sz) {
+			if (!(flags & MSG_PEEK))
+				TIPC_SKB_CB(buf)->handle =
+				(void *)(unsigned long)(offset + sz_to_copy);
+			goto exit;
+		}
+	} else {
+		if (sz_copied != 0)
+			goto exit; /* can't add error msg to valid data */
+
+		if ((err == TIPC_CONN_SHUTDOWN) || m->msg_control)
+			res = 0;
+		else
+			res = -ECONNRESET;
+	}
+
+	/* Consume received message (optional) */
+	if (likely(!(flags & MSG_PEEK))) {
+		if (unlikely(++tsk->rcv_unacked >= TIPC_CONNACK_INTV)) {
+			tipc_sk_send_ack(tsk, tsk->rcv_unacked);
+			tsk->rcv_unacked = 0;
+		}
+		tsk_advance_rx_queue(sk);
+	}
+
+	/* Loop around if more data is required */
+	if ((sz_copied < buf_len) &&	/* didn't get all requested data */
+	    (!skb_queue_empty(&sk->sk_receive_queue) ||
+	    (sz_copied < target)) &&	/* and more is ready or required */
+	    (!(flags & MSG_PEEK)) &&	/* and aren't just peeking at data */
+	    (!err))			/* and haven't reached a FIN */
+		goto restart;
+
+exit:
+	release_sock(sk);
+	return sz_copied ? sz_copied : res;
+}
+
+/**
+ * tipc_write_space - wake up thread if port congestion is released
+ * @sk: socket
+ */
+static void tipc_write_space(struct sock *sk)
+{
+	struct socket_wq *wq;
+
+	rcu_read_lock();
+	wq = rcu_dereference(sk->sk_wq);
+	if (wq_has_sleeper(wq))
+		wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
+						POLLWRNORM | POLLWRBAND);
+	rcu_read_unlock();
+}
+
+/**
+ * tipc_data_ready - wake up threads to indicate messages have been received
+ * @sk: socket
+ * @len: the length of messages
+ */
+static void tipc_data_ready(struct sock *sk)
+{
+	struct socket_wq *wq;
+
+	rcu_read_lock();
+	wq = rcu_dereference(sk->sk_wq);
+	if (wq_has_sleeper(wq))
+		wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
+						POLLRDNORM | POLLRDBAND);
+	rcu_read_unlock();
+}
+
+/**
+ * filter_connect - Handle all incoming messages for a connection-based socket
+ * @tsk: TIPC socket
+ * @skb: pointer to message buffer. Set to NULL if buffer is consumed
+ *
+ * Returns 0 (TIPC_OK) if everything ok, -TIPC_ERR_NO_PORT otherwise
+ */
+static int filter_connect(struct tipc_sock *tsk, struct sk_buff **skb)
+{
+	struct sock *sk = &tsk->sk;
+	struct net *net = sock_net(sk);
+	struct socket *sock = sk->sk_socket;
+	struct tipc_msg *msg = buf_msg(*skb);
+	int retval = -TIPC_ERR_NO_PORT;
+
+	if (msg_mcast(msg))
+		return retval;
+
+	switch ((int)sock->state) {
+	case SS_CONNECTED:
+		/* Accept only connection-based messages sent by peer */
+		if (tsk_peer_msg(tsk, msg)) {
+			if (unlikely(msg_errcode(msg))) {
+				sock->state = SS_DISCONNECTING;
+				tsk->connected = 0;
+				/* let timer expire on it's own */
+				tipc_node_remove_conn(net, tsk_peer_node(tsk),
+						      tsk->portid);
+			}
+			retval = TIPC_OK;
+		}
+		break;
+	case SS_CONNECTING:
+		/* Accept only ACK or NACK message */
+
+		if (unlikely(!msg_connected(msg)))
+			break;
+
+		if (unlikely(msg_errcode(msg))) {
+			sock->state = SS_DISCONNECTING;
+			sk->sk_err = ECONNREFUSED;
+			retval = TIPC_OK;
+			break;
+		}
+
+		if (unlikely(msg_importance(msg) > TIPC_CRITICAL_IMPORTANCE)) {
+			sock->state = SS_DISCONNECTING;
+			sk->sk_err = EINVAL;
+			retval = TIPC_OK;
+			break;
+		}
+
+		tipc_sk_finish_conn(tsk, msg_origport(msg), msg_orignode(msg));
+		msg_set_importance(&tsk->phdr, msg_importance(msg));
+		sock->state = SS_CONNECTED;
+
+		/* If an incoming message is an 'ACK-', it should be
+		 * discarded here because it doesn't contain useful
+		 * data. In addition, we should try to wake up
+		 * connect() routine if sleeping.
+		 */
+		if (msg_data_sz(msg) == 0) {
+			kfree_skb(*skb);
+			*skb = NULL;
+			if (waitqueue_active(sk_sleep(sk)))
+				wake_up_interruptible(sk_sleep(sk));
+		}
+		retval = TIPC_OK;
+		break;
+	case SS_LISTENING:
+	case SS_UNCONNECTED:
+		/* Accept only SYN message */
+		if (!msg_connected(msg) && !(msg_errcode(msg)))
+			retval = TIPC_OK;
+		break;
+	case SS_DISCONNECTING:
+		break;
+	default:
+		pr_err("Unknown socket state %u\n", sock->state);
+	}
+	return retval;
+}
+
+/**
+ * rcvbuf_limit - get proper overload limit of socket receive queue
+ * @sk: socket
+ * @buf: message
+ *
+ * For all connection oriented messages, irrespective of importance,
+ * the default overload value (i.e. 67MB) is set as limit.
+ *
+ * For all connectionless messages, by default new queue limits are
+ * as belows:
+ *
+ * TIPC_LOW_IMPORTANCE       (4 MB)
+ * TIPC_MEDIUM_IMPORTANCE    (8 MB)
+ * TIPC_HIGH_IMPORTANCE      (16 MB)
+ * TIPC_CRITICAL_IMPORTANCE  (32 MB)
+ *
+ * Returns overload limit according to corresponding message importance
+ */
+static unsigned int rcvbuf_limit(struct sock *sk, struct sk_buff *buf)
+{
+	struct tipc_msg *msg = buf_msg(buf);
+
+	if (msg_connected(msg))
+		return sysctl_tipc_rmem[2];
+
+	return sk->sk_rcvbuf >> TIPC_CRITICAL_IMPORTANCE <<
+		msg_importance(msg);
+}
+
+/**
+ * filter_rcv - validate incoming message
+ * @sk: socket
+ * @skb: pointer to message. Set to NULL if buffer is consumed.
+ *
+ * Enqueues message on receive queue if acceptable; optionally handles
+ * disconnect indication for a connected socket.
+ *
+ * Called with socket lock already taken
+ *
+ * Returns 0 (TIPC_OK) if message was ok, -TIPC error code if rejected
+ */
+static int filter_rcv(struct sock *sk, struct sk_buff **skb)
+{
+	struct socket *sock = sk->sk_socket;
+	struct tipc_sock *tsk = tipc_sk(sk);
+	struct tipc_msg *msg = buf_msg(*skb);
+	unsigned int limit = rcvbuf_limit(sk, *skb);
+	int rc = TIPC_OK;
+
+	if (unlikely(msg_user(msg) == CONN_MANAGER)) {
+		tipc_sk_proto_rcv(tsk, skb);
+		return TIPC_OK;
+	}
+
+	if (unlikely(msg_user(msg) == SOCK_WAKEUP)) {
+		kfree_skb(*skb);
+		tsk->link_cong = 0;
+		sk->sk_write_space(sk);
+		*skb = NULL;
+		return TIPC_OK;
+	}
+
+	/* Reject message if it is wrong sort of message for socket */
+	if (msg_type(msg) > TIPC_DIRECT_MSG)
+		return -TIPC_ERR_NO_PORT;
+
+	if (sock->state == SS_READY) {
+		if (msg_connected(msg))
+			return -TIPC_ERR_NO_PORT;
+	} else {
+		rc = filter_connect(tsk, skb);
+		if (rc != TIPC_OK || !*skb)
+			return rc;
+	}
+
+	/* Reject message if there isn't room to queue it */
+	if (sk_rmem_alloc_get(sk) + (*skb)->truesize >= limit)
+		return -TIPC_ERR_OVERLOAD;
+
+	/* Enqueue message */
+	TIPC_SKB_CB(*skb)->handle = NULL;
+	__skb_queue_tail(&sk->sk_receive_queue, *skb);
+	skb_set_owner_r(*skb, sk);
+
+	sk->sk_data_ready(sk);
+	*skb = NULL;
+	return TIPC_OK;
+}
+
+/**
+ * tipc_backlog_rcv - handle incoming message from backlog queue
+ * @sk: socket
+ * @skb: message
+ *
+ * Caller must hold socket lock
+ *
+ * Returns 0
+ */
+static int tipc_backlog_rcv(struct sock *sk, struct sk_buff *skb)
+{
+	int err;
+	atomic_t *dcnt;
+	u32 dnode;
+	struct tipc_sock *tsk = tipc_sk(sk);
+	struct net *net = sock_net(sk);
+	uint truesize = skb->truesize;
+
+	err = filter_rcv(sk, &skb);
+	if (likely(!skb)) {
+		dcnt = &tsk->dupl_rcvcnt;
+		if (atomic_read(dcnt) < TIPC_CONN_OVERLOAD_LIMIT)
+			atomic_add(truesize, dcnt);
+		return 0;
+	}
+	if (!err || tipc_msg_reverse(tsk_own_node(tsk), skb, &dnode, -err))
+		tipc_link_xmit_skb(net, skb, dnode, tsk->portid);
+	return 0;
+}
+
+/**
+ * tipc_sk_enqueue - extract all buffers with destination 'dport' from
+ *                   inputq and try adding them to socket or backlog queue
+ * @inputq: list of incoming buffers with potentially different destinations
+ * @sk: socket where the buffers should be enqueued
+ * @dport: port number for the socket
+ * @_skb: returned buffer to be forwarded or rejected, if applicable
+ *
+ * Caller must hold socket lock
+ *
+ * Returns TIPC_OK if all buffers enqueued, otherwise -TIPC_ERR_OVERLOAD
+ * or -TIPC_ERR_NO_PORT
+ */
+static int tipc_sk_enqueue(struct sk_buff_head *inputq, struct sock *sk,
+			   u32 dport, struct sk_buff **_skb)
+{
+	unsigned int lim;
+	atomic_t *dcnt;
+	int err;
+	struct sk_buff *skb;
+	unsigned long time_limit = jiffies + 2;
+
+	while (skb_queue_len(inputq)) {
+		if (unlikely(time_after_eq(jiffies, time_limit)))
+			return TIPC_OK;
+		skb = tipc_skb_dequeue(inputq, dport);
+		if (unlikely(!skb))
+			return TIPC_OK;
+		if (!sock_owned_by_user(sk)) {
+			err = filter_rcv(sk, &skb);
+			if (likely(!skb))
+				continue;
+			*_skb = skb;
+			return err;
+		}
+		dcnt = &tipc_sk(sk)->dupl_rcvcnt;
+		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)))
+			continue;
+		*_skb = skb;
+		return -TIPC_ERR_OVERLOAD;
+	}
+	return TIPC_OK;
+}
+
+/**
+ * tipc_sk_rcv - handle a chain of incoming buffers
+ * @inputq: buffer list containing the buffers
+ * Consumes all buffers in list until inputq is empty
+ * Note: may be called in multiple threads referring to the same queue
+ * Returns 0 if last buffer was accepted, otherwise -EHOSTUNREACH
+ * Only node local calls check the return value, sending single-buffer queues
+ */
+int tipc_sk_rcv(struct net *net, struct sk_buff_head *inputq)
+{
+	u32 dnode, dport = 0;
+	int err;
+	struct sk_buff *skb;
+	struct tipc_sock *tsk;
+	struct tipc_net *tn;
+	struct sock *sk;
+
+	while (skb_queue_len(inputq)) {
+		err = -TIPC_ERR_NO_PORT;
+		skb = NULL;
+		dport = tipc_skb_peek_port(inputq, dport);
+		tsk = tipc_sk_lookup(net, dport);
+		if (likely(tsk)) {
+			sk = &tsk->sk;
+			if (likely(spin_trylock_bh(&sk->sk_lock.slock))) {
+				err = tipc_sk_enqueue(inputq, sk, dport, &skb);
+				spin_unlock_bh(&sk->sk_lock.slock);
+				dport = 0;
+			}
+			sock_put(sk);
+		} else {
+			skb = tipc_skb_dequeue(inputq, dport);
+		}
+		if (likely(!skb))
+			continue;
+		if (tipc_msg_lookup_dest(net, skb, &dnode, &err))
+			goto xmit;
+		if (!err) {
+			dnode = msg_destnode(buf_msg(skb));
+			goto xmit;
+		}
+		tn = net_generic(net, tipc_net_id);
+		if (!tipc_msg_reverse(tn->own_addr, skb, &dnode, -err))
+			continue;
+xmit:
+		tipc_link_xmit_skb(net, skb, dnode, dport);
+	}
+	return err ? -EHOSTUNREACH : 0;
+}
+
+static int tipc_wait_for_connect(struct socket *sock, long *timeo_p)
+{
+	struct sock *sk = sock->sk;
+	DEFINE_WAIT(wait);
+	int done;
+
+	do {
+		int err = sock_error(sk);
+		if (err)
+			return err;
+		if (!*timeo_p)
+			return -ETIMEDOUT;
+		if (signal_pending(current))
+			return sock_intr_errno(*timeo_p);
+
+		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+		done = sk_wait_event(sk, timeo_p, sock->state != SS_CONNECTING);
+		finish_wait(sk_sleep(sk), &wait);
+	} while (!done);
+	return 0;
+}
+
+/**
+ * tipc_connect - establish a connection to another TIPC port
+ * @sock: socket structure
+ * @dest: socket address for destination port
+ * @destlen: size of socket address data structure
+ * @flags: file-related flags associated with socket
+ *
+ * Returns 0 on success, errno otherwise
+ */
+static int tipc_connect(struct socket *sock, struct sockaddr *dest,
+			int destlen, int flags)
+{
+	struct sock *sk = sock->sk;
+	struct tipc_sock *tsk = tipc_sk(sk);
+	struct sockaddr_tipc *dst = (struct sockaddr_tipc *)dest;
+	struct msghdr m = {NULL,};
+	long timeout = (flags & O_NONBLOCK) ? 0 : tsk->conn_timeout;
+	socket_state previous;
+	int res = 0;
+
+	lock_sock(sk);
+
+	/* DGRAM/RDM connect(), just save the destaddr */
+	if (sock->state == SS_READY) {
+		if (dst->family == AF_UNSPEC) {
+			memset(&tsk->remote, 0, sizeof(struct sockaddr_tipc));
+			tsk->connected = 0;
+		} else if (destlen != sizeof(struct sockaddr_tipc)) {
+			res = -EINVAL;
+		} else {
+			memcpy(&tsk->remote, dest, destlen);
+			tsk->connected = 1;
+		}
+		goto exit;
+	}
+
+	/*
+	 * Reject connection attempt using multicast address
+	 *
+	 * Note: send_msg() validates the rest of the address fields,
+	 *       so there's no need to do it here
+	 */
+	if (dst->addrtype == TIPC_ADDR_MCAST) {
+		res = -EINVAL;
+		goto exit;
+	}
+
+	previous = sock->state;
+	switch (sock->state) {
+	case SS_UNCONNECTED:
+		/* Send a 'SYN-' to destination */
+		m.msg_name = dest;
+		m.msg_namelen = destlen;
+
+		/* If connect is in non-blocking case, set MSG_DONTWAIT to
+		 * indicate send_msg() is never blocked.
+		 */
+		if (!timeout)
+			m.msg_flags = MSG_DONTWAIT;
+
+		res = __tipc_sendmsg(sock, &m, 0);
+		if ((res < 0) && (res != -EWOULDBLOCK))
+			goto exit;
+
+		/* Just entered SS_CONNECTING state; the only
+		 * difference is that return value in non-blocking
+		 * case is EINPROGRESS, rather than EALREADY.
+		 */
+		res = -EINPROGRESS;
+	case SS_CONNECTING:
+		if (previous == SS_CONNECTING)
+			res = -EALREADY;
+		if (!timeout)
+			goto exit;
+		timeout = msecs_to_jiffies(timeout);
+		/* Wait until an 'ACK' or 'RST' arrives, or a timeout occurs */
+		res = tipc_wait_for_connect(sock, &timeout);
+		break;
+	case SS_CONNECTED:
+		res = -EISCONN;
+		break;
+	default:
+		res = -EINVAL;
+		break;
+	}
+exit:
+	release_sock(sk);
+	return res;
+}
+
+/**
+ * tipc_listen - allow socket to listen for incoming connections
+ * @sock: socket structure
+ * @len: (unused)
+ *
+ * Returns 0 on success, errno otherwise
+ */
+static int tipc_listen(struct socket *sock, int len)
+{
+	struct sock *sk = sock->sk;
+	int res;
+
+	lock_sock(sk);
+
+	if (sock->state != SS_UNCONNECTED)
+		res = -EINVAL;
+	else {
+		sock->state = SS_LISTENING;
+		res = 0;
+	}
+
+	release_sock(sk);
+	return res;
+}
+
+static int tipc_wait_for_accept(struct socket *sock, long timeo)
+{
+	struct sock *sk = sock->sk;
+	DEFINE_WAIT(wait);
+	int err;
+
+	/* True wake-one mechanism for incoming connections: only
+	 * one process gets woken up, not the 'whole herd'.
+	 * Since we do not 'race & poll' for established sockets
+	 * anymore, the common case will execute the loop only once.
+	*/
+	for (;;) {
+		prepare_to_wait_exclusive(sk_sleep(sk), &wait,
+					  TASK_INTERRUPTIBLE);
+		if (timeo && skb_queue_empty(&sk->sk_receive_queue)) {
+			release_sock(sk);
+			timeo = schedule_timeout(timeo);
+			lock_sock(sk);
+		}
+		err = 0;
+		if (!skb_queue_empty(&sk->sk_receive_queue))
+			break;
+		err = -EINVAL;
+		if (sock->state != SS_LISTENING)
+			break;
+		err = -EAGAIN;
+		if (!timeo)
+			break;
+		err = sock_intr_errno(timeo);
+		if (signal_pending(current))
+			break;
+	}
+	finish_wait(sk_sleep(sk), &wait);
+	return err;
+}
+
+/**
+ * tipc_accept - wait for connection request
+ * @sock: listening socket
+ * @newsock: new socket that is to be connected
+ * @flags: file-related flags associated with socket
+ *
+ * Returns 0 on success, errno otherwise
+ */
+static int tipc_accept(struct socket *sock, struct socket *new_sock, int flags)
+{
+	struct sock *new_sk, *sk = sock->sk;
+	struct sk_buff *buf;
+	struct tipc_sock *new_tsock;
+	struct tipc_msg *msg;
+	long timeo;
+	int res;
+
+	lock_sock(sk);
+
+	if (sock->state != SS_LISTENING) {
+		res = -EINVAL;
+		goto exit;
+	}
+	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
+	res = tipc_wait_for_accept(sock, timeo);
+	if (res)
+		goto exit;
+
+	buf = skb_peek(&sk->sk_receive_queue);
+
+	res = tipc_sk_create(sock_net(sock->sk), new_sock, 0, 1);
+	if (res)
+		goto exit;
+
+	new_sk = new_sock->sk;
+	new_tsock = tipc_sk(new_sk);
+	msg = buf_msg(buf);
+
+	/* we lock on new_sk; but lockdep sees the lock on sk */
+	lock_sock_nested(new_sk, SINGLE_DEPTH_NESTING);
+
+	/*
+	 * Reject any stray messages received by new socket
+	 * before the socket lock was taken (very, very unlikely)
+	 */
+	tsk_rej_rx_queue(new_sk);
+
+	/* Connect new socket to it's peer */
+	tipc_sk_finish_conn(new_tsock, msg_origport(msg), msg_orignode(msg));
+	new_sock->state = SS_CONNECTED;
+
+	tsk_set_importance(new_tsock, msg_importance(msg));
+	if (msg_named(msg)) {
+		new_tsock->conn_type = msg_nametype(msg);
+		new_tsock->conn_instance = msg_nameinst(msg);
+	}
+
+	/*
+	 * Respond to 'SYN-' by discarding it & returning 'ACK'-.
+	 * Respond to 'SYN+' by queuing it on new socket.
+	 */
+	if (!msg_data_sz(msg)) {
+		struct msghdr m = {NULL,};
+
+		tsk_advance_rx_queue(sk);
+		__tipc_send_stream(new_sock, &m, 0);
+	} else {
+		__skb_dequeue(&sk->sk_receive_queue);
+		__skb_queue_head(&new_sk->sk_receive_queue, buf);
+		skb_set_owner_r(buf, new_sk);
+	}
+	release_sock(new_sk);
+exit:
+	release_sock(sk);
+	return res;
+}
+
+/**
+ * tipc_shutdown - shutdown socket connection
+ * @sock: socket structure
+ * @how: direction to close (must be SHUT_RDWR)
+ *
+ * Terminates connection (if necessary), then purges socket's receive queue.
+ *
+ * Returns 0 on success, errno otherwise
+ */
+static int tipc_shutdown(struct socket *sock, int how)
+{
+	struct sock *sk = sock->sk;
+	struct net *net = sock_net(sk);
+	struct tipc_sock *tsk = tipc_sk(sk);
+	struct sk_buff *skb;
+	u32 dnode;
+	int res;
+
+	if (how != SHUT_RDWR)
+		return -EINVAL;
+
+	lock_sock(sk);
+
+	switch (sock->state) {
+	case SS_CONNECTING:
+	case SS_CONNECTED:
+
+restart:
+		/* Disconnect and send a 'FIN+' or 'FIN-' message to peer */
+		skb = __skb_dequeue(&sk->sk_receive_queue);
+		if (skb) {
+			if (TIPC_SKB_CB(skb)->handle != NULL) {
+				kfree_skb(skb);
+				goto restart;
+			}
+			if (tipc_msg_reverse(tsk_own_node(tsk), skb, &dnode,
+					     TIPC_CONN_SHUTDOWN))
+				tipc_link_xmit_skb(net, skb, dnode,
+						   tsk->portid);
+		} else {
+			dnode = tsk_peer_node(tsk);
+
+			skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE,
+					      TIPC_CONN_MSG, SHORT_H_SIZE,
+					      0, dnode, tsk_own_node(tsk),
+					      tsk_peer_port(tsk),
+					      tsk->portid, TIPC_CONN_SHUTDOWN);
+			tipc_link_xmit_skb(net, skb, dnode, tsk->portid);
+		}
+		tsk->connected = 0;
+		sock->state = SS_DISCONNECTING;
+		tipc_node_remove_conn(net, dnode, tsk->portid);
+		/* fall through */
+
+	case SS_DISCONNECTING:
+
+		/* Discard any unreceived messages */
+		__skb_queue_purge(&sk->sk_receive_queue);
+
+		/* Wake up anyone sleeping in poll */
+		sk->sk_state_change(sk);
+		res = 0;
+		break;
+
+	default:
+		res = -ENOTCONN;
+	}
+
+	release_sock(sk);
+	return res;
+}
+
+static void tipc_sk_timeout(unsigned long data)
+{
+	struct tipc_sock *tsk = (struct tipc_sock *)data;
+	struct sock *sk = &tsk->sk;
+	struct sk_buff *skb = NULL;
+	u32 peer_port, peer_node;
+	u32 own_node = tsk_own_node(tsk);
+
+	bh_lock_sock(sk);
+	if (!tsk->connected) {
+		bh_unlock_sock(sk);
+		goto exit;
+	}
+	peer_port = tsk_peer_port(tsk);
+	peer_node = tsk_peer_node(tsk);
+
+	if (tsk->probing_state == TIPC_CONN_PROBING) {
+		if (!sock_owned_by_user(sk)) {
+			sk->sk_socket->state = SS_DISCONNECTING;
+			tsk->connected = 0;
+			tipc_node_remove_conn(sock_net(sk), tsk_peer_node(tsk),
+					      tsk_peer_port(tsk));
+			sk->sk_state_change(sk);
+		} else {
+			/* Try again later */
+			sk_reset_timer(sk, &sk->sk_timer, (HZ / 20));
+		}
+
+	} else {
+		skb = tipc_msg_create(CONN_MANAGER, CONN_PROBE,
+				      INT_H_SIZE, 0, peer_node, own_node,
+				      peer_port, tsk->portid, TIPC_OK);
+		tsk->probing_state = TIPC_CONN_PROBING;
+		sk_reset_timer(sk, &sk->sk_timer, jiffies + tsk->probing_intv);
+	}
+	bh_unlock_sock(sk);
+	if (skb)
+		tipc_link_xmit_skb(sock_net(sk), skb, peer_node, tsk->portid);
+exit:
+	sock_put(sk);
+}
+
+static int tipc_sk_publish(struct tipc_sock *tsk, uint scope,
+			   struct tipc_name_seq const *seq)
+{
+	struct net *net = sock_net(&tsk->sk);
+	struct publication *publ;
+	u32 key;
+
+	if (tsk->connected)
+		return -EINVAL;
+	key = tsk->portid + tsk->pub_count + 1;
+	if (key == tsk->portid)
+		return -EADDRINUSE;
+
+	publ = tipc_nametbl_publish(net, seq->type, seq->lower, seq->upper,
+				    scope, tsk->portid, key);
+	if (unlikely(!publ))
+		return -EINVAL;
+
+	list_add(&publ->pport_list, &tsk->publications);
+	tsk->pub_count++;
+	tsk->published = 1;
+	return 0;
+}
+
+static int tipc_sk_withdraw(struct tipc_sock *tsk, uint scope,
+			    struct tipc_name_seq const *seq)
+{
+	struct net *net = sock_net(&tsk->sk);
+	struct publication *publ;
+	struct publication *safe;
+	int rc = -EINVAL;
+
+	list_for_each_entry_safe(publ, safe, &tsk->publications, pport_list) {
+		if (seq) {
+			if (publ->scope != scope)
+				continue;
+			if (publ->type != seq->type)
+				continue;
+			if (publ->lower != seq->lower)
+				continue;
+			if (publ->upper != seq->upper)
+				break;
+			tipc_nametbl_withdraw(net, publ->type, publ->lower,
+					      publ->ref, publ->key);
+			rc = 0;
+			break;
+		}
+		tipc_nametbl_withdraw(net, publ->type, publ->lower,
+				      publ->ref, publ->key);
+		rc = 0;
+	}
+	if (list_empty(&tsk->publications))
+		tsk->published = 0;
+	return rc;
+}
+
+/* tipc_sk_reinit: set non-zero address in all existing sockets
+ *                 when we go from standalone to network mode.
+ */
+void tipc_sk_reinit(struct net *net)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	const struct bucket_table *tbl;
+	struct rhash_head *pos;
+	struct tipc_sock *tsk;
+	struct tipc_msg *msg;
+	int i;
+
+	rcu_read_lock();
+	tbl = rht_dereference_rcu((&tn->sk_rht)->tbl, &tn->sk_rht);
+	for (i = 0; i < tbl->size; i++) {
+		rht_for_each_entry_rcu(tsk, pos, tbl, i, node) {
+			spin_lock_bh(&tsk->sk.sk_lock.slock);
+			msg = &tsk->phdr;
+			msg_set_prevnode(msg, tn->own_addr);
+			msg_set_orignode(msg, tn->own_addr);
+			spin_unlock_bh(&tsk->sk.sk_lock.slock);
+		}
+	}
+	rcu_read_unlock();
+}
+
+static struct tipc_sock *tipc_sk_lookup(struct net *net, u32 portid)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_sock *tsk;
+
+	rcu_read_lock();
+	tsk = rhashtable_lookup_fast(&tn->sk_rht, &portid, tsk_rht_params);
+	if (tsk)
+		sock_hold(&tsk->sk);
+	rcu_read_unlock();
+
+	return tsk;
+}
+
+static int tipc_sk_insert(struct tipc_sock *tsk)
+{
+	struct sock *sk = &tsk->sk;
+	struct net *net = sock_net(sk);
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	u32 remaining = (TIPC_MAX_PORT - TIPC_MIN_PORT) + 1;
+	u32 portid = prandom_u32() % remaining + TIPC_MIN_PORT;
+
+	while (remaining--) {
+		portid++;
+		if ((portid < TIPC_MIN_PORT) || (portid > TIPC_MAX_PORT))
+			portid = TIPC_MIN_PORT;
+		tsk->portid = portid;
+		sock_hold(&tsk->sk);
+		if (!rhashtable_lookup_insert_fast(&tn->sk_rht, &tsk->node,
+						   tsk_rht_params))
+			return 0;
+		sock_put(&tsk->sk);
+	}
+
+	return -1;
+}
+
+static void tipc_sk_remove(struct tipc_sock *tsk)
+{
+	struct sock *sk = &tsk->sk;
+	struct tipc_net *tn = net_generic(sock_net(sk), tipc_net_id);
+
+	if (!rhashtable_remove_fast(&tn->sk_rht, &tsk->node, tsk_rht_params)) {
+		WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
+		__sock_put(sk);
+	}
+}
+
+static const struct rhashtable_params tsk_rht_params = {
+	.nelem_hint = 192,
+	.head_offset = offsetof(struct tipc_sock, node),
+	.key_offset = offsetof(struct tipc_sock, portid),
+	.key_len = sizeof(u32), /* portid */
+	.max_size = 1048576,
+	.min_size = 256,
+	.automatic_shrinking = true,
+};
+
+int tipc_sk_rht_init(struct net *net)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+
+	return rhashtable_init(&tn->sk_rht, &tsk_rht_params);
+}
+
+void tipc_sk_rht_destroy(struct net *net)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+
+	/* Wait for socket readers to complete */
+	synchronize_net();
+
+	rhashtable_destroy(&tn->sk_rht);
+}
+
+/**
+ * tipc_setsockopt - set socket option
+ * @sock: socket structure
+ * @lvl: option level
+ * @opt: option identifier
+ * @ov: pointer to new option value
+ * @ol: length of option value
+ *
+ * For stream sockets only, accepts and ignores all IPPROTO_TCP options
+ * (to ease compatibility).
+ *
+ * Returns 0 on success, errno otherwise
+ */
+static int tipc_setsockopt(struct socket *sock, int lvl, int opt,
+			   char __user *ov, unsigned int ol)
+{
+	struct sock *sk = sock->sk;
+	struct tipc_sock *tsk = tipc_sk(sk);
+	u32 value;
+	int res;
+
+	if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM))
+		return 0;
+	if (lvl != SOL_TIPC)
+		return -ENOPROTOOPT;
+	if (ol < sizeof(value))
+		return -EINVAL;
+	res = get_user(value, (u32 __user *)ov);
+	if (res)
+		return res;
+
+	lock_sock(sk);
+
+	switch (opt) {
+	case TIPC_IMPORTANCE:
+		res = tsk_set_importance(tsk, value);
+		break;
+	case TIPC_SRC_DROPPABLE:
+		if (sock->type != SOCK_STREAM)
+			tsk_set_unreliable(tsk, value);
+		else
+			res = -ENOPROTOOPT;
+		break;
+	case TIPC_DEST_DROPPABLE:
+		tsk_set_unreturnable(tsk, value);
+		break;
+	case TIPC_CONN_TIMEOUT:
+		tipc_sk(sk)->conn_timeout = value;
+		/* no need to set "res", since already 0 at this point */
+		break;
+	default:
+		res = -EINVAL;
+	}
+
+	release_sock(sk);
+
+	return res;
+}
+
+/**
+ * tipc_getsockopt - get socket option
+ * @sock: socket structure
+ * @lvl: option level
+ * @opt: option identifier
+ * @ov: receptacle for option value
+ * @ol: receptacle for length of option value
+ *
+ * For stream sockets only, returns 0 length result for all IPPROTO_TCP options
+ * (to ease compatibility).
+ *
+ * Returns 0 on success, errno otherwise
+ */
+static int tipc_getsockopt(struct socket *sock, int lvl, int opt,
+			   char __user *ov, int __user *ol)
+{
+	struct sock *sk = sock->sk;
+	struct tipc_sock *tsk = tipc_sk(sk);
+	int len;
+	u32 value;
+	int res;
+
+	if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM))
+		return put_user(0, ol);
+	if (lvl != SOL_TIPC)
+		return -ENOPROTOOPT;
+	res = get_user(len, ol);
+	if (res)
+		return res;
+
+	lock_sock(sk);
+
+	switch (opt) {
+	case TIPC_IMPORTANCE:
+		value = tsk_importance(tsk);
+		break;
+	case TIPC_SRC_DROPPABLE:
+		value = tsk_unreliable(tsk);
+		break;
+	case TIPC_DEST_DROPPABLE:
+		value = tsk_unreturnable(tsk);
+		break;
+	case TIPC_CONN_TIMEOUT:
+		value = tsk->conn_timeout;
+		/* no need to set "res", since already 0 at this point */
+		break;
+	case TIPC_NODE_RECVQ_DEPTH:
+		value = 0; /* was tipc_queue_size, now obsolete */
+		break;
+	case TIPC_SOCK_RECVQ_DEPTH:
+		value = skb_queue_len(&sk->sk_receive_queue);
+		break;
+	default:
+		res = -EINVAL;
+	}
+
+	release_sock(sk);
+
+	if (res)
+		return res;	/* "get" failed */
+
+	if (len < sizeof(value))
+		return -EINVAL;
+
+	if (copy_to_user(ov, &value, sizeof(value)))
+		return -EFAULT;
+
+	return put_user(sizeof(value), ol);
+}
+
+static int tipc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+{
+	struct sock *sk = sock->sk;
+	struct tipc_sioc_ln_req lnr;
+	void __user *argp = (void __user *)arg;
+
+	switch (cmd) {
+	case SIOCGETLINKNAME:
+		if (copy_from_user(&lnr, argp, sizeof(lnr)))
+			return -EFAULT;
+		if (!tipc_node_get_linkname(sock_net(sk),
+					    lnr.bearer_id & 0xffff, lnr.peer,
+					    lnr.linkname, TIPC_MAX_LINK_NAME)) {
+			if (copy_to_user(argp, &lnr, sizeof(lnr)))
+				return -EFAULT;
+			return 0;
+		}
+		return -EADDRNOTAVAIL;
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
+/* Protocol switches for the various types of TIPC sockets */
+
+static const struct proto_ops msg_ops = {
+	.owner		= THIS_MODULE,
+	.family		= AF_TIPC,
+	.release	= tipc_release,
+	.bind		= tipc_bind,
+	.connect	= tipc_connect,
+	.socketpair	= sock_no_socketpair,
+	.accept		= sock_no_accept,
+	.getname	= tipc_getname,
+	.poll		= tipc_poll,
+	.ioctl		= tipc_ioctl,
+	.listen		= sock_no_listen,
+	.shutdown	= tipc_shutdown,
+	.setsockopt	= tipc_setsockopt,
+	.getsockopt	= tipc_getsockopt,
+	.sendmsg	= tipc_sendmsg,
+	.recvmsg	= tipc_recvmsg,
+	.mmap		= sock_no_mmap,
+	.sendpage	= sock_no_sendpage
+};
+
+static const struct proto_ops packet_ops = {
+	.owner		= THIS_MODULE,
+	.family		= AF_TIPC,
+	.release	= tipc_release,
+	.bind		= tipc_bind,
+	.connect	= tipc_connect,
+	.socketpair	= sock_no_socketpair,
+	.accept		= tipc_accept,
+	.getname	= tipc_getname,
+	.poll		= tipc_poll,
+	.ioctl		= tipc_ioctl,
+	.listen		= tipc_listen,
+	.shutdown	= tipc_shutdown,
+	.setsockopt	= tipc_setsockopt,
+	.getsockopt	= tipc_getsockopt,
+	.sendmsg	= tipc_send_packet,
+	.recvmsg	= tipc_recvmsg,
+	.mmap		= sock_no_mmap,
+	.sendpage	= sock_no_sendpage
+};
+
+static const struct proto_ops stream_ops = {
+	.owner		= THIS_MODULE,
+	.family		= AF_TIPC,
+	.release	= tipc_release,
+	.bind		= tipc_bind,
+	.connect	= tipc_connect,
+	.socketpair	= sock_no_socketpair,
+	.accept		= tipc_accept,
+	.getname	= tipc_getname,
+	.poll		= tipc_poll,
+	.ioctl		= tipc_ioctl,
+	.listen		= tipc_listen,
+	.shutdown	= tipc_shutdown,
+	.setsockopt	= tipc_setsockopt,
+	.getsockopt	= tipc_getsockopt,
+	.sendmsg	= tipc_send_stream,
+	.recvmsg	= tipc_recv_stream,
+	.mmap		= sock_no_mmap,
+	.sendpage	= sock_no_sendpage
+};
+
+static const struct net_proto_family tipc_family_ops = {
+	.owner		= THIS_MODULE,
+	.family		= AF_TIPC,
+	.create		= tipc_sk_create
+};
+
+static struct proto tipc_proto = {
+	.name		= "TIPC",
+	.owner		= THIS_MODULE,
+	.obj_size	= sizeof(struct tipc_sock),
+	.sysctl_rmem	= sysctl_tipc_rmem
+};
+
+/**
+ * tipc_socket_init - initialize TIPC socket interface
+ *
+ * Returns 0 on success, errno otherwise
+ */
+int tipc_socket_init(void)
+{
+	int res;
+
+	res = proto_register(&tipc_proto, 1);
+	if (res) {
+		pr_err("Failed to register TIPC protocol type\n");
+		goto out;
+	}
+
+	res = sock_register(&tipc_family_ops);
+	if (res) {
+		pr_err("Failed to register TIPC socket type\n");
+		proto_unregister(&tipc_proto);
+		goto out;
+	}
+ out:
+	return res;
+}
+
+/**
+ * tipc_socket_stop - stop TIPC socket interface
+ */
+void tipc_socket_stop(void)
+{
+	sock_unregister(tipc_family_ops.family);
+	proto_unregister(&tipc_proto);
+}
+
+/* Caller should hold socket lock for the passed tipc socket. */
+static int __tipc_nl_add_sk_con(struct sk_buff *skb, struct tipc_sock *tsk)
+{
+	u32 peer_node;
+	u32 peer_port;
+	struct nlattr *nest;
+
+	peer_node = tsk_peer_node(tsk);
+	peer_port = tsk_peer_port(tsk);
+
+	nest = nla_nest_start(skb, TIPC_NLA_SOCK_CON);
+
+	if (nla_put_u32(skb, TIPC_NLA_CON_NODE, peer_node))
+		goto msg_full;
+	if (nla_put_u32(skb, TIPC_NLA_CON_SOCK, peer_port))
+		goto msg_full;
+
+	if (tsk->conn_type != 0) {
+		if (nla_put_flag(skb, TIPC_NLA_CON_FLAG))
+			goto msg_full;
+		if (nla_put_u32(skb, TIPC_NLA_CON_TYPE, tsk->conn_type))
+			goto msg_full;
+		if (nla_put_u32(skb, TIPC_NLA_CON_INST, tsk->conn_instance))
+			goto msg_full;
+	}
+	nla_nest_end(skb, nest);
+
+	return 0;
+
+msg_full:
+	nla_nest_cancel(skb, nest);
+
+	return -EMSGSIZE;
+}
+
+/* Caller should hold socket lock for the passed tipc socket. */
+static int __tipc_nl_add_sk(struct sk_buff *skb, struct netlink_callback *cb,
+			    struct tipc_sock *tsk)
+{
+	int err;
+	void *hdr;
+	struct nlattr *attrs;
+	struct net *net = sock_net(skb->sk);
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+
+	hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
+			  &tipc_genl_family, NLM_F_MULTI, TIPC_NL_SOCK_GET);
+	if (!hdr)
+		goto msg_cancel;
+
+	attrs = nla_nest_start(skb, TIPC_NLA_SOCK);
+	if (!attrs)
+		goto genlmsg_cancel;
+	if (nla_put_u32(skb, TIPC_NLA_SOCK_REF, tsk->portid))
+		goto attr_msg_cancel;
+	if (nla_put_u32(skb, TIPC_NLA_SOCK_ADDR, tn->own_addr))
+		goto attr_msg_cancel;
+
+	if (tsk->connected) {
+		err = __tipc_nl_add_sk_con(skb, tsk);
+		if (err)
+			goto attr_msg_cancel;
+	} else if (!list_empty(&tsk->publications)) {
+		if (nla_put_flag(skb, TIPC_NLA_SOCK_HAS_PUBL))
+			goto attr_msg_cancel;
+	}
+	nla_nest_end(skb, attrs);
+	genlmsg_end(skb, hdr);
+
+	return 0;
+
+attr_msg_cancel:
+	nla_nest_cancel(skb, attrs);
+genlmsg_cancel:
+	genlmsg_cancel(skb, hdr);
+msg_cancel:
+	return -EMSGSIZE;
+}
+
+int tipc_nl_sk_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	int err;
+	struct tipc_sock *tsk;
+	const struct bucket_table *tbl;
+	struct rhash_head *pos;
+	struct net *net = sock_net(skb->sk);
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	u32 tbl_id = cb->args[0];
+	u32 prev_portid = cb->args[1];
+
+	rcu_read_lock();
+	tbl = rht_dereference_rcu((&tn->sk_rht)->tbl, &tn->sk_rht);
+	for (; tbl_id < tbl->size; tbl_id++) {
+		rht_for_each_entry_rcu(tsk, pos, tbl, tbl_id, node) {
+			spin_lock_bh(&tsk->sk.sk_lock.slock);
+			if (prev_portid && prev_portid != tsk->portid) {
+				spin_unlock_bh(&tsk->sk.sk_lock.slock);
+				continue;
+			}
+
+			err = __tipc_nl_add_sk(skb, cb, tsk);
+			if (err) {
+				prev_portid = tsk->portid;
+				spin_unlock_bh(&tsk->sk.sk_lock.slock);
+				goto out;
+			}
+			prev_portid = 0;
+			spin_unlock_bh(&tsk->sk.sk_lock.slock);
+		}
+	}
+out:
+	rcu_read_unlock();
+	cb->args[0] = tbl_id;
+	cb->args[1] = prev_portid;
+
+	return skb->len;
+}
+
+/* Caller should hold socket lock for the passed tipc socket. */
+static int __tipc_nl_add_sk_publ(struct sk_buff *skb,
+				 struct netlink_callback *cb,
+				 struct publication *publ)
+{
+	void *hdr;
+	struct nlattr *attrs;
+
+	hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
+			  &tipc_genl_family, NLM_F_MULTI, TIPC_NL_PUBL_GET);
+	if (!hdr)
+		goto msg_cancel;
+
+	attrs = nla_nest_start(skb, TIPC_NLA_PUBL);
+	if (!attrs)
+		goto genlmsg_cancel;
+
+	if (nla_put_u32(skb, TIPC_NLA_PUBL_KEY, publ->key))
+		goto attr_msg_cancel;
+	if (nla_put_u32(skb, TIPC_NLA_PUBL_TYPE, publ->type))
+		goto attr_msg_cancel;
+	if (nla_put_u32(skb, TIPC_NLA_PUBL_LOWER, publ->lower))
+		goto attr_msg_cancel;
+	if (nla_put_u32(skb, TIPC_NLA_PUBL_UPPER, publ->upper))
+		goto attr_msg_cancel;
+
+	nla_nest_end(skb, attrs);
+	genlmsg_end(skb, hdr);
+
+	return 0;
+
+attr_msg_cancel:
+	nla_nest_cancel(skb, attrs);
+genlmsg_cancel:
+	genlmsg_cancel(skb, hdr);
+msg_cancel:
+	return -EMSGSIZE;
+}
+
+/* Caller should hold socket lock for the passed tipc socket. */
+static int __tipc_nl_list_sk_publ(struct sk_buff *skb,
+				  struct netlink_callback *cb,
+				  struct tipc_sock *tsk, u32 *last_publ)
+{
+	int err;
+	struct publication *p;
+
+	if (*last_publ) {
+		list_for_each_entry(p, &tsk->publications, pport_list) {
+			if (p->key == *last_publ)
+				break;
+		}
+		if (p->key != *last_publ) {
+			/* We never set seq or call nl_dump_check_consistent()
+			 * this means that setting prev_seq here will cause the
+			 * consistence check to fail in the netlink callback
+			 * handler. Resulting in the last NLMSG_DONE message
+			 * having the NLM_F_DUMP_INTR flag set.
+			 */
+			cb->prev_seq = 1;
+			*last_publ = 0;
+			return -EPIPE;
+		}
+	} else {
+		p = list_first_entry(&tsk->publications, struct publication,
+				     pport_list);
+	}
+
+	list_for_each_entry_from(p, &tsk->publications, pport_list) {
+		err = __tipc_nl_add_sk_publ(skb, cb, p);
+		if (err) {
+			*last_publ = p->key;
+			return err;
+		}
+	}
+	*last_publ = 0;
+
+	return 0;
+}
+
+int tipc_nl_publ_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	int err;
+	u32 tsk_portid = cb->args[0];
+	u32 last_publ = cb->args[1];
+	u32 done = cb->args[2];
+	struct net *net = sock_net(skb->sk);
+	struct tipc_sock *tsk;
+
+	if (!tsk_portid) {
+		struct nlattr **attrs;
+		struct nlattr *sock[TIPC_NLA_SOCK_MAX + 1];
+
+		err = tipc_nlmsg_parse(cb->nlh, &attrs);
+		if (err)
+			return err;
+
+		err = nla_parse_nested(sock, TIPC_NLA_SOCK_MAX,
+				       attrs[TIPC_NLA_SOCK],
+				       tipc_nl_sock_policy);
+		if (err)
+			return err;
+
+		if (!sock[TIPC_NLA_SOCK_REF])
+			return -EINVAL;
+
+		tsk_portid = nla_get_u32(sock[TIPC_NLA_SOCK_REF]);
+	}
+
+	if (done)
+		return 0;
+
+	tsk = tipc_sk_lookup(net, tsk_portid);
+	if (!tsk)
+		return -EINVAL;
+
+	lock_sock(&tsk->sk);
+	err = __tipc_nl_list_sk_publ(skb, cb, tsk, &last_publ);
+	if (!err)
+		done = 1;
+	release_sock(&tsk->sk);
+	sock_put(&tsk->sk);
+
+	cb->args[0] = tsk_portid;
+	cb->args[1] = last_publ;
+	cb->args[2] = done;
+
+	return skb->len;
+}