Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / net / tipc / socket.c
diff --git a/kernel/net/tipc/socket.c b/kernel/net/tipc/socket.c
new file mode 100644 (file)
index 0000000..f485600
--- /dev/null
@@ -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;
+}