tipc: Ensure congested links receive bearer status updates

[deliverable/linux.git] / net / tipc / node.h

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

#ifndef _TIPC_NODE_H
#define _TIPC_NODE_H

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

/**
 * 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
 * @list: links to adjacent nodes in sorted list of cluster's nodes
 * @nsub: list of "node down" subscriptions monitoring node
 * @active_links: pointers to active links to node
 * @links: pointers to all links to node
 * @working_links: number of working links to node (both active and standby)
 * @cleanup_required: non-zero if cleaning up after a prior loss of contact
 * @link_cnt: number of links to node
 * @permit_changeover: non-zero if node has redundant links to this system
 * @bclink: broadcast-related info
 *    @supported: non-zero if node supports TIPC b'cast capability
 *    @acked: sequence # of last outbound b'cast message acknowledged by node
 *    @last_in: sequence # of last in-sequence b'cast message received from node
 *    @gap_after: sequence # of last message not requiring a NAK request
 *    @gap_to: sequence # of last message requiring a NAK request
 *    @nack_sync: counter that determines when NAK requests should be sent
 *    @deferred_head: oldest OOS b'cast message received from node
 *    @deferred_tail: newest OOS b'cast message received from node
 *    @defragm: list of partially reassembled b'cast message fragments from node
 */

struct tipc_node {
	u32 addr;
	spinlock_t lock;
	struct hlist_node hash;
	struct list_head list;
	struct list_head nsub;
	struct link *active_links[2];
	struct link *links[MAX_BEARERS];
	int link_cnt;
	int working_links;
	int cleanup_required;
	int permit_changeover;
	struct {
		int supported;
		u32 acked;
		u32 last_in;
		u32 gap_after;
		u32 gap_to;
		u32 nack_sync;
		struct sk_buff *deferred_head;
		struct sk_buff *deferred_tail;
		struct sk_buff *defragm;
	} bclink;
};

#define NODE_HTABLE_SIZE 512
extern struct list_head tipc_node_list;

/*
 * A trivial power-of-two bitmask technique is used for speed, since this
 * operation is done for every incoming TIPC packet. The number of hash table
 * entries has been chosen so that no hash chain exceeds 8 nodes and will
 * usually be much smaller (typically only a single node).
 */
static inline unsigned int tipc_hashfn(u32 addr)
{
	return addr & (NODE_HTABLE_SIZE - 1);
}

extern u32 tipc_own_tag;

struct tipc_node *tipc_node_find(u32 addr);
struct tipc_node *tipc_node_create(u32 addr);
void tipc_node_delete(struct tipc_node *n_ptr);
void tipc_node_attach_link(struct tipc_node *n_ptr, struct link *l_ptr);
void tipc_node_detach_link(struct tipc_node *n_ptr, struct link *l_ptr);
void tipc_node_link_down(struct tipc_node *n_ptr, struct link *l_ptr);
void tipc_node_link_up(struct tipc_node *n_ptr, struct link *l_ptr);
int tipc_node_active_links(struct tipc_node *n_ptr);
int tipc_node_redundant_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);

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

static inline void tipc_node_unlock(struct tipc_node *n_ptr)
{
	spin_unlock_bh(&n_ptr->lock);
}

#endif