node.h

/*
 * net/tipc/node.h: Include file for TIPC node management routines
 *
 * Copyright (c) 2000-2006, Ericsson AB
 * Copyright (c) 2005, 2010-2014, 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.
 */

#ifndef _TIPC_NODE_H
#define _TIPC_NODE_H

#include "node_subscr.h"
#include "addr.h"
#include "net.h"
#include "bearer.h"

/*
 * Out-of-range value for node signature
 */
#define INVALID_NODE_SIG 0x10000

/* Flags used to block (re)establishment of contact with a neighboring node
 * TIPC_NODE_DOWN: indicate node is down and it's used to block the node's
 *                 links until RESET or ACTIVE message arrives
 * TIPC_NODE_RESET: indicate node is reset
 * TIPC_NODE_LOST: indicate node is lost and it's used to notify subscriptions
 *                 when node lock is released
 * TIPC_NODE_UP: indicate node is up and it's used to deliver local name table
 *               when node lock is released
 */
enum {
	TIPC_NODE_DOWN	= (1 << 1),
	TIPC_NODE_RESET	= (1 << 2),
	TIPC_NODE_LOST	= (1 << 3),
	TIPC_NODE_UP	= (1 << 4)
};

/**
 * struct tipc_node_bclink - TIPC node bclink structure
 * @acked: sequence # of last outbound b'cast message acknowledged by node
 * @last_in: sequence # of last in-sequence b'cast message received from node
 * @last_sent: sequence # of last b'cast message sent by node
 * @oos_state: state tracker for handling OOS b'cast messages
 * @deferred_size: number of OOS b'cast messages in deferred queue
 * @deferred_head: oldest OOS b'cast message received from node
 * @deferred_tail: newest OOS b'cast message received from node
 * @reasm_head: broadcast reassembly queue head from node
 * @reasm_tail: last broadcast fragment received from node
 * @recv_permitted: true if node is allowed to receive b'cast messages
 */
struct tipc_node_bclink {
	u32 acked;
	u32 last_in;
	u32 last_sent;
	u32 oos_state;
	u32 deferred_size;
	struct sk_buff *deferred_head;
	struct sk_buff *deferred_tail;
	struct sk_buff *reasm_head;
	struct sk_buff *reasm_tail;
	bool recv_permitted;
};

/**
 * struct tipc_node - TIPC node structure
 * @addr: network address of node
 * @lock: spinlock governing access to structure
 * @hash: links to adjacent nodes in unsorted hash chain
 * @active_links: pointers to active links to node
 * @links: pointers to all links to node
 * @flags: bit mask of conditions preventing link establishment to node
 * @bclink: broadcast-related info
 * @list: links to adjacent nodes in sorted list of cluster's nodes
 * @working_links: number of working links to node (both active and standby)
 * @link_cnt: number of links to node
 * @signature: node instance identifier
 * @nsub: list of "node down" subscriptions monitoring node
 * @rcu: rcu struct for tipc_node
 */
struct tipc_node {
	u32 addr;
	spinlock_t lock;
	struct hlist_node hash;
	struct tipc_link *active_links[2];
	struct tipc_link *links[MAX_BEARERS];
	unsigned int flags;
	struct tipc_node_bclink bclink;
	struct list_head list;
	int link_cnt;
	int working_links;
	u32 signature;
	struct list_head nsub;
	struct rcu_head rcu;
};

extern struct list_head tipc_node_list;

struct tipc_node *tipc_node_find(u32 addr);
struct tipc_node *tipc_node_create(u32 addr);
void tipc_node_stop(void);
void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr);
void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr);
void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr);
void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr);
int tipc_node_active_links(struct tipc_node *n_ptr);
int tipc_node_is_up(struct tipc_node *n_ptr);
struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space);
struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space);
int tipc_node_get_linkname(u32 bearer_id, u32 node, char *linkname, size_t len);
void tipc_node_unlock(struct tipc_node *node);

static inline void tipc_node_lock(struct tipc_node *node)
{
	spin_lock_bh(&node->lock);
}

static inline bool tipc_node_blocked(struct tipc_node *node)
{
	return (node->flags & (TIPC_NODE_DOWN | TIPC_NODE_LOST |
		TIPC_NODE_RESET));
}

#endif