text: /*
   * net/tipc/server.c: TIPC server infrastructure
   *
   * Copyright (c) 2012-2013, Wind River Systems
   * Copyright (c) 2017-2018, Ericsson AB
   * 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 "subscr.h"
  #include "topsrv.h"
  #include "core.h"
  #include "socket.h"
  #include "addr.h"
  #include "msg.h"
  #include <net/sock.h>
  #include <linux/module.h>
  
  /* Number of messages to send before rescheduling */
  #define MAX_SEND_MSG_COUNT	25
  #define MAX_RECV_MSG_COUNT	25
  #define CF_CONNECTED		1
  #define CF_SERVER		2
  
  #define TIPC_SERVER_NAME_LEN	32
  
  /**
   * struct tipc_topsrv - TIPC server structure
   * @conn_idr: identifier set of connection
   * @idr_lock: protect the connection identifier set
   * @idr_in_use: amount of allocated identifier entry
   * @net: network namspace instance
   * @rcvbuf_cache: memory cache of server receive buffer
   * @rcv_wq: receive workqueue
   * @send_wq: send workqueue
   * @max_rcvbuf_size: maximum permitted receive message length
   * @tipc_conn_new: callback will be called when new connection is incoming
   * @tipc_conn_release: callback will be called before releasing the connection
   * @tipc_conn_recvmsg: callback will be called when message arrives
   * @name: server name
   * @imp: message importance
   * @type: socket type
   */
  struct tipc_topsrv {
  	struct idr conn_idr;
  	spinlock_t idr_lock; /* for idr list */
  	int idr_in_use;
  	struct net *net;
  	struct work_struct awork;
  	struct workqueue_struct *rcv_wq;
  	struct workqueue_struct *send_wq;
  	int max_rcvbuf_size;
  	struct socket *listener;
  	char name[TIPC_SERVER_NAME_LEN];
  };
  
  /**
   * struct tipc_conn - TIPC connection structure
   * @kref: reference counter to connection object
   * @conid: connection identifier
   * @sock: socket handler associated with connection
   * @flags: indicates connection state
   * @server: pointer to connected server
   * @sub_list: lsit to all pertaing subscriptions
   * @sub_lock: lock protecting the subscription list
   * @outqueue_lock: control access to the outqueue
   * @rwork: receive work item
   * @rx_action: what to do when connection socket is active
   * @outqueue: pointer to first outbound message in queue
   * @outqueue_lock: control access to the outqueue
   * @swork: send work item
   */
  struct tipc_conn {
  	struct kref kref;
  	int conid;
  	struct socket *sock;
  	unsigned long flags;
  	struct tipc_topsrv *server;
  	struct list_head sub_list;
  	spinlock_t sub_lock; /* for subscription list */
  	struct work_struct rwork;
  	struct list_head outqueue;
  	spinlock_t outqueue_lock; /* for outqueue */
  	struct work_struct swork;
  };
  
  /* An entry waiting to be sent */
  struct outqueue_entry {
  	bool inactive;
  	struct tipc_event evt;
  	struct list_head list;
  };
  
  static void tipc_conn_recv_work(struct work_struct *work);
  static void tipc_conn_send_work(struct work_struct *work);
  static void tipc_topsrv_kern_evt(struct net *net, struct tipc_event *evt);
  static void tipc_conn_delete_sub(struct tipc_conn *con, struct tipc_subscr *s);
  
  static bool connected(struct tipc_conn *con)
  {
  	return con && test_bit(CF_CONNECTED, &con->flags);
  }
  
  static void tipc_conn_kref_release(struct kref *kref)
  {
  	struct tipc_conn *con = container_of(kref, struct tipc_conn, kref);
  	struct tipc_topsrv *s = con->server;
  	struct outqueue_entry *e, *safe;
  
  	spin_lock_bh(&s->idr_lock);
  	idr_remove(&s->conn_idr, con->conid);
  	s->idr_in_use--;
  	spin_unlock_bh(&s->idr_lock);
  	if (con->sock)
  		sock_release(con->sock);
  
  	spin_lock_bh(&con->outqueue_lock);
  	list_for_each_entry_safe(e, safe, &con->outqueue, list) {
  		list_del(&e->list);
  		kfree(e);
  	}
  	spin_unlock_bh(&con->outqueue_lock);
  	kfree(con);
  }
  
  static void conn_put(struct tipc_conn *con)
  {
  	kref_put(&con->kref, tipc_conn_kref_release);
  }
  
  static void conn_get(struct tipc_conn *con)
  {
  	kref_get(&con->kref);
  }
  
  static void tipc_conn_close(struct tipc_conn *con)
  {
  	struct sock *sk = con->sock->sk;
  	bool disconnect = false;
  
  	write_lock_bh(&sk->sk_callback_lock);
  	disconnect = test_and_clear_bit(CF_CONNECTED, &con->flags);
  
  	if (disconnect) {
  		sk->sk_user_data = NULL;
  		tipc_conn_delete_sub(con, NULL);
  	}
  	write_unlock_bh(&sk->sk_callback_lock);
  
  	/* Handle concurrent calls from sending and receiving threads */
  	if (!disconnect)
  		return;
  
  	/* Don't flush pending works, -just let them expire */
  	kernel_sock_shutdown(con->sock, SHUT_RDWR);
  
  	conn_put(con);
  }
  
  static struct tipc_conn *tipc_conn_alloc(struct tipc_topsrv *s)
  {
  	struct tipc_conn *con;
  	int ret;
  
  	con = kzalloc(sizeof(*con), GFP_ATOMIC);
  	if (!con)
  		return ERR_PTR(-ENOMEM);
  
  	kref_init(&con->kref);
  	INIT_LIST_HEAD(&con->outqueue);
  	INIT_LIST_HEAD(&con->sub_list);
  	spin_lock_init(&con->outqueue_lock);
  	spin_lock_init(&con->sub_lock);
  	INIT_WORK(&con->swork, tipc_conn_send_work);
  	INIT_WORK(&con->rwork, tipc_conn_recv_work);
  
  	spin_lock_bh(&s->idr_lock);
  	ret = idr_alloc(&s->conn_idr, con, 0, 0, GFP_ATOMIC);
  	if (ret < 0) {
  		kfree(con);
  		spin_unlock_bh(&s->idr_lock);
  		return ERR_PTR(-ENOMEM);
  	}
  	con->conid = ret;
  	s->idr_in_use++;
  	spin_unlock_bh(&s->idr_lock);
  
  	set_bit(CF_CONNECTED, &con->flags);
  	con->server = s;
  
  	return con;
  }
  
  static struct tipc_conn *tipc_conn_lookup(struct tipc_topsrv *s, int conid)
  {
  	struct tipc_conn *con;
  
  	spin_lock_bh(&s->idr_lock);
  	con = idr_find(&s->conn_idr, conid);
  	if (!connected(con) || !kref_get_unless_zero(&con->kref))
  		con = NULL;
  	spin_unlock_bh(&s->idr_lock);
  	return con;
  }
  
  /* tipc_conn_delete_sub - delete a specific or all subscriptions
   * for a given subscriber
   */
  static void tipc_conn_delete_sub(struct tipc_conn *con, struct tipc_subscr *s)
  {
  	struct tipc_net *tn = tipc_net(con->server->net);
  	struct list_head *sub_list = &con->sub_list;
  	struct tipc_subscription *sub, *tmp;
  
  	spin_lock_bh(&con->sub_lock);
  	list_for_each_entry_safe(sub, tmp, sub_list, sub_list) {
  		if (!s || !memcmp(s, &sub->evt.s, sizeof(*s))) {
  			tipc_sub_unsubscribe(sub);
  			atomic_dec(&tn->subscription_count);
  		} else if (s) {
  			break;
  		}
  	}
  	spin_unlock_bh(&con->sub_lock);
  }
  
  static void tipc_conn_send_to_sock(struct tipc_conn *con)
  {
  	struct list_head *queue = &con->outqueue;
  	struct tipc_topsrv *srv = con->server;
  	struct outqueue_entry *e;
  	struct tipc_event *evt;
  	struct msghdr msg;
  	struct kvec iov;
  	int count = 0;
  	int ret;
  
  	spin_lock_bh(&con->outqueue_lock);
  
  	while (!list_empty(queue)) {
  		e = list_first_entry(queue, struct outqueue_entry, list);
  		evt = &e->evt;
  		spin_unlock_bh(&con->outqueue_lock);
  
  		if (e->inactive)
  			tipc_conn_delete_sub(con, &evt->s);
  
  		memset(&msg, 0, sizeof(msg));
  		msg.msg_flags = MSG_DONTWAIT;
  		iov.iov_base = evt;
  		iov.iov_len = sizeof(*evt);
  		msg.msg_name = NULL;
  
  		if (con->sock) {
  			ret = kernel_sendmsg(con->sock, &msg, &iov,
  					     1, sizeof(*evt));
  			if (ret == -EWOULDBLOCK || ret == 0) {
  				cond_resched();
  				return;
  			} else if (ret < 0) {
  				return tipc_conn_close(con);
  			}
  		} else {
  			tipc_topsrv_kern_evt(srv->net, evt);
  		}
  
  		/* Don't starve users filling buffers */
  		if (++count >= MAX_SEND_MSG_COUNT) {
  			cond_resched();
  			count = 0;
  		}
  		spin_lock_bh(&con->outqueue_lock);
  		list_del(&e->list);
  		kfree(e);
  	}
  	spin_unlock_bh(&con->outqueue_lock);
  }
  
  static void tipc_conn_send_work(struct work_struct *work)
  {
  	struct tipc_conn *con = container_of(work, struct tipc_conn, swork);
  
  	if (connected(con))
  		tipc_conn_send_to_sock(con);
  
  	conn_put(con);
  }
  
  /* tipc_topsrv_queue_evt() - interrupt level call from a subscription instance
   * The queued work is launched into tipc_conn_send_work()->tipc_conn_send_to_sock()
   */
  void tipc_topsrv_queue_evt(struct net *net, int conid,
  			   u32 event, struct tipc_event *evt)
  {
  	struct tipc_topsrv *srv = tipc_topsrv(net);
  	struct outqueue_entry *e;
  	struct tipc_conn *con;
  
  	con = tipc_conn_lookup(srv, conid);
  	if (!con)
  		return;
  
  	if (!connected(con))
  		goto err;
  
  	e = kmalloc(sizeof(*e), GFP_ATOMIC);
  	if (!e)
  		goto err;
  	e->inactive = (event == TIPC_SUBSCR_TIMEOUT);
  	memcpy(&e->evt, evt, sizeof(*evt));
  	spin_lock_bh(&con->outqueue_lock);
  	list_add_tail(&e->list, &con->outqueue);
  	spin_unlock_bh(&con->outqueue_lock);
  
  	if (queue_work(srv->send_wq, &con->swork))
  		return;
  err:
  	conn_put(con);
  }
  
  /* tipc_conn_write_space - interrupt callback after a sendmsg EAGAIN
   * Indicates that there now is more space in the send buffer
   * The queued work is launched into tipc_send_work()->tipc_conn_send_to_sock()
   */
  static void tipc_conn_write_space(struct sock *sk)
  {
  	struct tipc_conn *con;
  
  	read_lock_bh(&sk->sk_callback_lock);
  	con = sk->sk_user_data;
  	if (connected(con)) {
  		conn_get(con);
  		if (!queue_work(con->server->send_wq, &con->swork))
  			conn_put(con);
  	}
  	read_unlock_bh(&sk->sk_callback_lock);
  }
  
  static int tipc_conn_rcv_sub(struct tipc_topsrv *srv,
  			     struct tipc_conn *con,
  			     struct tipc_subscr *s)
  {
  	struct tipc_net *tn = tipc_net(srv->net);
  	struct tipc_subscription *sub;
  
  	if (tipc_sub_read(s, filter) & TIPC_SUB_CANCEL) {
  		s->filter &= __constant_ntohl(~TIPC_SUB_CANCEL);
  		tipc_conn_delete_sub(con, s);
  		return 0;
  	}
  	if (atomic_read(&tn->subscription_count) >= TIPC_MAX_SUBSCR) {
  		pr_warn("Subscription rejected, max (%u)\n", TIPC_MAX_SUBSCR);
  		return -1;
  	}
  	sub = tipc_sub_subscribe(srv->net, s, con->conid);
  	if (!sub)
  		return -1;
  	atomic_inc(&tn->subscription_count);
  	spin_lock_bh(&con->sub_lock);
  	list_add(&sub->sub_list, &con->sub_list);
  	spin_unlock_bh(&con->sub_lock);
  	return 0;
  }
  
  static int tipc_conn_rcv_from_sock(struct tipc_conn *con)
  {
  	struct tipc_topsrv *srv = con->server;
  	struct sock *sk = con->sock->sk;
  	struct msghdr msg = {};
  	struct tipc_subscr s;
  	struct kvec iov;
  	int ret;
  
  	iov.iov_base = &s;
  	iov.iov_len = sizeof(s);
  	msg.msg_name = NULL;
  	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &iov, 1, iov.iov_len);
  	ret = sock_recvmsg(con->sock, &msg, MSG_DONTWAIT);
  	if (ret == -EWOULDBLOCK)
  		return -EWOULDBLOCK;
  	if (ret == sizeof(s)) {
  		read_lock_bh(&sk->sk_callback_lock);
  		ret = tipc_conn_rcv_sub(srv, con, &s);
  		read_unlock_bh(&sk->sk_callback_lock);
  	}
  	if (ret < 0)
  		tipc_conn_close(con);
  
  	return ret;
  }
  
  static void tipc_conn_recv_work(struct work_struct *work)
  {
  	struct tipc_conn *con = container_of(work, struct tipc_conn, rwork);
  	int count = 0;
  
  	while (connected(con)) {
  		if (tipc_conn_rcv_from_sock(con))
  			break;
  
  		/* Don't flood Rx machine */
  		if (++count >= MAX_RECV_MSG_COUNT) {
  			cond_resched();
  			count = 0;
  		}
  	}
  	conn_put(con);
  }
  
  /* tipc_conn_data_ready - interrupt callback indicating the socket has data
   * The queued work is launched into tipc_recv_work()->tipc_conn_rcv_from_sock()
   */
  static void tipc_conn_data_ready(struct sock *sk)
  {
  	struct tipc_conn *con;
  
  	read_lock_bh(&sk->sk_callback_lock);
  	con = sk->sk_user_data;
  	if (connected(con)) {
  		conn_get(con);
  		if (!queue_work(con->server->rcv_wq, &con->rwork))
  			conn_put(con);
  	}
  	read_unlock_bh(&sk->sk_callback_lock);
  }
  
  static void tipc_topsrv_accept(struct work_struct *work)
  {
  	struct tipc_topsrv *srv = container_of(work, struct tipc_topsrv, awork);
  	struct socket *lsock = srv->listener;
  	struct socket *newsock;
  	struct tipc_conn *con;
  	struct sock *newsk;
  	int ret;
  
  	while (1) {
  		ret = kernel_accept(lsock, &newsock, O_NONBLOCK);
  		if (ret < 0)
  			return;
  		con = tipc_conn_alloc(srv);
  		if (IS_ERR(con)) {
  			ret = PTR_ERR(con);
  			sock_release(newsock);
  			return;
  		}
  		/* Register callbacks */
  		newsk = newsock->sk;
  		write_lock_bh(&newsk->sk_callback_lock);
  		newsk->sk_data_ready = tipc_conn_data_ready;
  		newsk->sk_write_space = tipc_conn_write_space;
  		newsk->sk_user_data = con;
  		con->sock = newsock;
  		write_unlock_bh(&newsk->sk_callback_lock);
  
  		/* Wake up receive process in case of 'SYN+' message */
  		newsk->sk_data_ready(newsk);
  	}
  }
  
  /* tipc_toprsv_listener_data_ready - interrupt callback with connection request
   * The queued job is launched into tipc_topsrv_accept()
   */
  static void tipc_topsrv_listener_data_ready(struct sock *sk)
  {
  	struct tipc_topsrv *srv;
  
  	read_lock_bh(&sk->sk_callback_lock);
  	srv = sk->sk_user_data;
  	if (srv->listener)
  		queue_work(srv->rcv_wq, &srv->awork);
  	read_unlock_bh(&sk->sk_callback_lock);
  }
  
  static int tipc_topsrv_create_listener(struct tipc_topsrv *srv)
  {
  	int imp = TIPC_CRITICAL_IMPORTANCE;
  	struct socket *lsock = NULL;
  	struct sockaddr_tipc saddr;
  	struct sock *sk;
  	int rc;
  
  	rc = sock_create_kern(srv->net, AF_TIPC, SOCK_SEQPACKET, 0, &lsock);
  	if (rc < 0)
  		return rc;
  
  	srv->listener = lsock;
  	sk = lsock->sk;
  	write_lock_bh(&sk->sk_callback_lock);
  	sk->sk_data_ready = tipc_topsrv_listener_data_ready;
  	sk->sk_user_data = srv;
  	write_unlock_bh(&sk->sk_callback_lock);
  
  	rc = kernel_setsockopt(lsock, SOL_TIPC, TIPC_IMPORTANCE,
  			       (char *)&imp, sizeof(imp));
  	if (rc < 0)
  		goto err;
  
  	saddr.family	                = AF_TIPC;
  	saddr.addrtype		        = TIPC_ADDR_NAMESEQ;
  	saddr.addr.nameseq.type	        = TIPC_TOP_SRV;
  	saddr.addr.nameseq.lower	= TIPC_TOP_SRV;
  	saddr.addr.nameseq.upper	= TIPC_TOP_SRV;
  	saddr.scope			= TIPC_NODE_SCOPE;
  
  	rc = kernel_bind(lsock, (struct sockaddr *)&saddr, sizeof(saddr));
  	if (rc < 0)
  		goto err;
  	rc = kernel_listen(lsock, 0);
  	if (rc < 0)
  		goto err;
  
  	/* As server's listening socket owner and creator is the same module,
  	 * we have to decrease TIPC module reference count to guarantee that
  	 * it remains zero after the server socket is created, otherwise,
  	 * executing "rmmod" command is unable to make TIPC module deleted
  	 * after TIPC module is inserted successfully.
  	 *
  	 * However, the reference count is ever increased twice in
  	 * sock_create_kern(): one is to increase the reference count of owner
  	 * of TIPC socket's proto_ops struct; another is to increment the
  	 * reference count of owner of TIPC proto struct. Therefore, we must
  	 * decrement the module reference count twice to ensure that it keeps
  	 * zero after server's listening socket is created. Of course, we
  	 * must bump the module reference count twice as well before the socket
  	 * is closed.
  	 */
  	module_put(lsock->ops->owner);
  	module_put(sk->sk_prot_creator->owner);
  
  	return 0;
  err:
  	sock_release(lsock);
  	return -EINVAL;
  }
  
  bool tipc_topsrv_kern_subscr(struct net *net, u32 port, u32 type, u32 lower,
  			     u32 upper, u32 filter, int *conid)
  {
  	struct tipc_subscr sub;
  	struct tipc_conn *con;
  	int rc;
  
  	sub.seq.type = type;
  	sub.seq.lower = lower;
  	sub.seq.upper = upper;
  	sub.timeout = TIPC_WAIT_FOREVER;
  	sub.filter = filter;
  	*(u32 *)&sub.usr_handle = port;
  
  	con = tipc_conn_alloc(tipc_topsrv(net));
  	if (IS_ERR(con))
  		return false;
  
  	*conid = con->conid;
  	con->sock = NULL;
  	rc = tipc_conn_rcv_sub(tipc_topsrv(net), con, &sub);
  	if (rc >= 0)
  		return true;
  	conn_put(con);
  	return false;
  }
  
  void tipc_topsrv_kern_unsubscr(struct net *net, int conid)
  {
  	struct tipc_conn *con;
  
  	con = tipc_conn_lookup(tipc_topsrv(net), conid);
  	if (!con)
  		return;
  
  	test_and_clear_bit(CF_CONNECTED, &con->flags);
  	tipc_conn_delete_sub(con, NULL);
  	conn_put(con);
  	conn_put(con);
  }
  
  static void tipc_topsrv_kern_evt(struct net *net, struct tipc_event *evt)
  {
  	u32 port = *(u32 *)&evt->s.usr_handle;
  	u32 self = tipc_own_addr(net);
  	struct sk_buff_head evtq;
  	struct sk_buff *skb;
  
  	skb = tipc_msg_create(TOP_SRV, 0, INT_H_SIZE, sizeof(*evt),
  			      self, self, port, port, 0);
  	if (!skb)
  		return;
  	msg_set_dest_droppable(buf_msg(skb), true);
  	memcpy(msg_data(buf_msg(skb)), evt, sizeof(*evt));
  	skb_queue_head_init(&evtq);
  	__skb_queue_tail(&evtq, skb);
  	tipc_sk_rcv(net, &evtq);
  }
  
  static int tipc_topsrv_work_start(struct tipc_topsrv *s)
  {
  	s->rcv_wq = alloc_ordered_workqueue("tipc_rcv", 0);
  	if (!s->rcv_wq) {
  		pr_err("can't start tipc receive workqueue\n");
  		return -ENOMEM;
  	}
  
  	s->send_wq = alloc_ordered_workqueue("tipc_send", 0);
  	if (!s->send_wq) {
  		pr_err("can't start tipc send workqueue\n");
  		destroy_workqueue(s->rcv_wq);
  		return -ENOMEM;
  	}
  
  	return 0;
  }
  
  static void tipc_topsrv_work_stop(struct tipc_topsrv *s)
  {
  	destroy_workqueue(s->rcv_wq);
  	destroy_workqueue(s->send_wq);
  }
  
  static int tipc_topsrv_start(struct net *net)
  {
  	struct tipc_net *tn = tipc_net(net);
  	const char name[] = "topology_server";
  	struct tipc_topsrv *srv;
  	int ret;
  
  	srv = kzalloc(sizeof(*srv), GFP_ATOMIC);
  	if (!srv)
  		return -ENOMEM;
  
  	srv->net = net;
  	srv->max_rcvbuf_size = sizeof(struct tipc_subscr);
  	INIT_WORK(&srv->awork, tipc_topsrv_accept);
  
  	strscpy(srv->name, name, sizeof(srv->name));
  	tn->topsrv = srv;
  	atomic_set(&tn->subscription_count, 0);
  
  	spin_lock_init(&srv->idr_lock);
  	idr_init(&srv->conn_idr);
  	srv->idr_in_use = 0;
  
  	ret = tipc_topsrv_work_start(srv);
  	if (ret < 0)
  		return ret;
  
  	ret = tipc_topsrv_create_listener(srv);
  	if (ret < 0)
  		tipc_topsrv_work_stop(srv);
  
  	return ret;
  }
  
  static void tipc_topsrv_stop(struct net *net)
  {
  	struct tipc_topsrv *srv = tipc_topsrv(net);
  	struct socket *lsock = srv->listener;
  	struct tipc_conn *con;
  	int id;
  
  	spin_lock_bh(&srv->idr_lock);
  	for (id = 0; srv->idr_in_use; id++) {
  		con = idr_find(&srv->conn_idr, id);
  		if (con) {
  			spin_unlock_bh(&srv->idr_lock);
  			tipc_conn_close(con);
  			spin_lock_bh(&srv->idr_lock);
  		}
  	}
  	__module_get(lsock->ops->owner);
  	__module_get(lsock->sk->sk_prot_creator->owner);
  	srv->listener = NULL;
  	spin_unlock_bh(&srv->idr_lock);
  	sock_release(lsock);
  	tipc_topsrv_work_stop(srv);
  	idr_destroy(&srv->conn_idr);
  	kfree(srv);
  }
  
  int __net_init tipc_topsrv_init_net(struct net *net)
  {
  	return tipc_topsrv_start(net);
  }
  
  void __net_exit tipc_topsrv_exit_net(struct net *net)
  {
  	tipc_topsrv_stop(net);
  }
  