path: root/net/netrom/nr_route.c

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Copyright Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
 * Copyright Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
 * Copyright Tomi Manninen OH2BNS (oh2bns@sral.fi)
 */
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <net/arp.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <linux/fcntl.h>
#include <linux/termios.h>	/* For TIOCINQ/OUTQ */
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/netfilter.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <net/netrom.h>
#include <linux/seq_file.h>

static unsigned int nr_neigh_no = 1;

static HLIST_HEAD(nr_node_list);
static DEFINE_SPINLOCK(nr_node_list_lock);
static HLIST_HEAD(nr_neigh_list);
static DEFINE_SPINLOCK(nr_neigh_list_lock);

static struct nr_node *nr_node_get(ax25_address *callsign)
{
	struct nr_node *found = NULL;
	struct nr_node *nr_node;
	struct hlist_node *node;

	spin_lock_bh(&nr_node_list_lock);
	nr_node_for_each(nr_node, node, &nr_node_list)
		if (ax25cmp(callsign, &nr_node->callsign) == 0) {
			nr_node_hold(nr_node);
			found = nr_node;
			break;
		}
	spin_unlock_bh(&nr_node_list_lock);
	return found;
}

static struct nr_neigh *nr_neigh_get_dev(ax25_address *callsign,
					 struct net_device *dev)
{
	struct nr_neigh *found = NULL;
	struct nr_neigh *nr_neigh;
	struct hlist_node *node;

	spin_lock_bh(&nr_neigh_list_lock);
	nr_neigh_for_each(nr_neigh, node, &nr_neigh_list)
		if (ax25cmp(callsign, &nr_neigh->callsign) == 0 &&
		    nr_neigh->dev == dev) {
			nr_neigh_hold(nr_neigh);
			found = nr_neigh;
			break;
		}
	spin_unlock_bh(&nr_neigh_list_lock);
	return found;
}

static void nr_remove_neigh(struct nr_neigh *);

/*
 *	Add a new route to a node, and in the process add the node and the
 *	neighbour if it is new.
 */
static int nr_add_node(ax25_address *nr, const char *mnemonic, ax25_address *ax25,
	ax25_digi *ax25_digi, struct net_device *dev, int quality, int obs_count)
{
	struct nr_node  *nr_node;
	struct nr_neigh *nr_neigh;
	struct nr_route nr_route;
	int i, found;
	struct net_device *odev;

	if ((odev=nr_dev_get(nr)) != NULL) {	/* Can't add routes to ourself */
		dev_put(odev);
		return -EINVAL;
	}

	nr_node = nr_node_get(nr);

	nr_neigh = nr_neigh_get_dev(ax25, dev);

	/*
	 * The L2 link to a neighbour has failed in the past
	 * and now a frame comes from this neighbour. We assume
	 * it was a temporary trouble with the link and reset the
	 * routes now (and not wait for a node broadcast).
	 */
	if (nr_neigh != NULL && nr_neigh->failed != 0 && quality == 0) {
		struct nr_node *nr_nodet;
		struct hlist_node *node;

		spin_lock_bh(&nr_node_list_lock);
		nr_node_for_each(nr_nodet, node, &nr_node_list) {
			nr_node_lock(nr_nodet);
			for (i = 0; i < nr_nodet->count; i++)
				if (nr_nodet->routes[i].neighbour == nr_neigh)
					if (i < nr_nodet->which)
						nr_nodet->which = i;
			nr_node_unlock(nr_nodet);
		}
		spin_unlock_bh(&nr_node_list_lock);
	}

	if (nr_neigh != NULL)
		nr_neigh->failed = 0;

	if (quality == 0 && nr_neigh != NULL && nr_node != NULL) {
		nr_neigh_put(nr_neigh);
		nr_node_put(nr_node);
		return 0;
	}

	if (nr_neigh == NULL