/*

   * net/tipc/subscr.c: TIPC network topology service

   *

   * Copyright (c) 2000-2017, Ericsson AB

   * Copyright (c) 2005-2007, 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 "core.h"

  #include "name_table.h"

  #include "subscr.h"

  static void tipc_sub_send_event(struct tipc_subscription *sub,
  				u32 found_lower, u32 found_upper,
  				u32 event, u32 port, u32 node)

  {

  	struct tipc_event *evt = &sub->evt;

  	if (sub->inactive)
  		return;

  	tipc_evt_write(evt, event, event);
  	tipc_evt_write(evt, found_lower, found_lower);
  	tipc_evt_write(evt, found_upper, found_upper);
  	tipc_evt_write(evt, port.ref, port);
  	tipc_evt_write(evt, port.node, node);

  	tipc_topsrv_queue_evt(sub->net, sub->conid, event, evt);

  }
  
  /**

   * tipc_sub_check_overlap - test for subscription overlap with the

   * given values

   *
   * Returns 1 if there is overlap, otherwise 0.
   */

  int tipc_sub_check_overlap(struct tipc_name_seq *seq, u32 found_lower,
  			   u32 found_upper)

  {

  	if (found_lower < seq->lower)
  		found_lower = seq->lower;
  	if (found_upper > seq->upper)
  		found_upper = seq->upper;

  	if (found_lower > found_upper)
  		return 0;
  	return 1;
  }

  void tipc_sub_report_overlap(struct tipc_subscription *sub,
  			     u32 found_lower, u32 found_upper,
  			     u32 event, u32 port, u32 node,
  			     u32 scope, int must)

  {

  	struct tipc_subscr *s = &sub->evt.s;
  	u32 filter = tipc_sub_read(s, filter);

  	struct tipc_name_seq seq;

  
  	seq.type = tipc_sub_read(s, seq.type);
  	seq.lower = tipc_sub_read(s, seq.lower);
  	seq.upper = tipc_sub_read(s, seq.upper);

  	if (!tipc_sub_check_overlap(&seq, found_lower, found_upper))

  		return;

  	if (!must && !(filter & TIPC_SUB_PORTS))
  		return;
  	if (filter & TIPC_SUB_CLUSTER_SCOPE && scope == TIPC_NODE_SCOPE)
  		return;
  	if (filter & TIPC_SUB_NODE_SCOPE && scope != TIPC_NODE_SCOPE)

  		return;

  	spin_lock(&sub->lock);

  	tipc_sub_send_event(sub, found_lower, found_upper,
  			    event, port, node);

  	spin_unlock(&sub->lock);

  }

  static void tipc_sub_timeout(struct timer_list *t)

  {

  	struct tipc_subscription *sub = from_timer(sub, t, timer);

  	struct tipc_subscr *s = &sub->evt.s;

  	spin_lock(&sub->lock);

  	tipc_sub_send_event(sub, s->seq.lower, s->seq.upper,
  			    TIPC_SUBSCR_TIMEOUT, 0, 0);

  	sub->inactive = true;
  	spin_unlock(&sub->lock);

  }

  static void tipc_sub_kref_release(struct kref *kref)

  {

  	kfree(container_of(kref, struct tipc_subscription, kref));

  }

  void tipc_sub_put(struct tipc_subscription *subscription)

  {

  	kref_put(&subscription->kref, tipc_sub_kref_release);

  }

  void tipc_sub_get(struct tipc_subscription *subscription)

  {
  	kref_get(&subscription->kref);
  }

  struct tipc_subscription *tipc_sub_subscribe(struct net *net,

  					     struct tipc_subscr *s,
  					     int conid)

  {

  	u32 filter = tipc_sub_read(s, filter);

  	struct tipc_subscription *sub;

  	u32 timeout;

  	if ((filter & TIPC_SUB_PORTS && filter & TIPC_SUB_SERVICE) ||
  	    (tipc_sub_read(s, seq.lower) > tipc_sub_read(s, seq.upper))) {
  		pr_warn("Subscription rejected, illegal request
  ");

  		return NULL;

  	}

  	sub = kmalloc(sizeof(*sub), GFP_ATOMIC);

  	if (!sub) {

  		pr_warn("Subscription rejected, no memory
  ");

  		return NULL;

  	}

  	INIT_LIST_HEAD(&sub->service_list);
  	INIT_LIST_HEAD(&sub->sub_list);

  	sub->net = net;

  	sub->conid = conid;
  	sub->inactive = false;

  	memcpy(&sub->evt.s, s, sizeof(*s));

  	spin_lock_init(&sub->lock);

  	kref_init(&sub->kref);

  	if (!tipc_nametbl_subscribe(sub)) {
  		kfree(sub);
  		return NULL;
  	}

  	timer_setup(&sub->timer, tipc_sub_timeout, 0);

  	timeout = tipc_sub_read(&sub->evt.s, timeout);

  	if (timeout != TIPC_WAIT_FOREVER)
  		mod_timer(&sub->timer, jiffies + msecs_to_jiffies(timeout));

  	return sub;

  }

  void tipc_sub_unsubscribe(struct tipc_subscription *sub)

  {

  	tipc_nametbl_unsubscribe(sub);
  	if (sub->evt.s.timeout != TIPC_WAIT_FOREVER)
  		del_timer_sync(&sub->timer);

  	list_del(&sub->sub_list);
  	tipc_sub_put(sub);

  }