/*
   * net/tipc/node_subscr.c: TIPC "node down" subscription handling
   *
   * Copyright (c) 1995-2006, Ericsson AB
   * Copyright (c) 2005, 2010-2011, 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 "node_subscr.h"
  #include "node.h"
  
  /**
   * tipc_nodesub_subscribe - create "node down" subscription for specified node
   */
  void tipc_nodesub_subscribe(struct tipc_node_subscr *node_sub, u32 addr,
  			    void *usr_handle, net_ev_handler handle_down)
  {
  	if (in_own_node(addr)) {
  		node_sub->node = NULL;
  		return;
  	}
  
  	node_sub->node = tipc_node_find(addr);
  	if (!node_sub->node) {
  		pr_warn("Node subscription rejected, unknown node 0x%x
  ",
  			addr);
  		return;
  	}
  	node_sub->handle_node_down = handle_down;
  	node_sub->usr_handle = usr_handle;
  
  	tipc_node_lock(node_sub->node);
  	list_add_tail(&node_sub->nodesub_list, &node_sub->node->nsub);
  	tipc_node_unlock(node_sub->node);
  }
  
  /**
   * tipc_nodesub_unsubscribe - cancel "node down" subscription (if any)
   */
  void tipc_nodesub_unsubscribe(struct tipc_node_subscr *node_sub)
  {
  	if (!node_sub->node)
  		return;
  
  	tipc_node_lock(node_sub->node);
  	list_del_init(&node_sub->nodesub_list);
  	tipc_node_unlock(node_sub->node);
  }
  
  /**
   * tipc_nodesub_notify - notify subscribers that a node is unreachable
   *
   * Note: node is locked by caller
   */
  void tipc_nodesub_notify(struct tipc_node *node)
  {
  	struct tipc_node_subscr *ns;
  
  	list_for_each_entry(ns, &node->nsub, nodesub_list) {
  		if (ns->handle_node_down) {
  			tipc_k_signal((Handler)ns->handle_node_down,
  				      (unsigned long)ns->usr_handle);
  			ns->handle_node_down = NULL;
  		}
  	}
  }