// SPDX-License-Identifier: GPL-2.0-or-later

  /*

   *
   * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
   * Copyright (C) Terry Dawson VK2KTJ (terry@animats.net)
   */
  #include <linux/errno.h>
  #include <linux/types.h>
  #include <linux/socket.h>
  #include <linux/in.h>
  #include <linux/kernel.h>

  #include <linux/timer.h>
  #include <linux/string.h>
  #include <linux/sockios.h>
  #include <linux/net.h>

  #include <linux/slab.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 <net/tcp_states.h>

  #include <linux/uaccess.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/init.h>
  #include <net/rose.h>
  #include <linux/seq_file.h>

  #include <linux/export.h>

  
  static unsigned int rose_neigh_no = 1;
  
  static struct rose_node  *rose_node_list;
  static DEFINE_SPINLOCK(rose_node_list_lock);
  static struct rose_neigh *rose_neigh_list;
  static DEFINE_SPINLOCK(rose_neigh_list_lock);
  static struct rose_route *rose_route_list;
  static DEFINE_SPINLOCK(rose_route_list_lock);

  struct rose_neigh *rose_loopback_neigh;

  /*
   *	Add a new route to a node, and in the process add the node and the
   *	neighbour if it is new.
   */

  static int __must_check rose_add_node(struct rose_route_struct *rose_route,

  	struct net_device *dev)
  {
  	struct rose_node  *rose_node, *rose_tmpn, *rose_tmpp;
  	struct rose_neigh *rose_neigh;
  	int i, res = 0;
  
  	spin_lock_bh(&rose_node_list_lock);
  	spin_lock_bh(&rose_neigh_list_lock);
  
  	rose_node = rose_node_list;
  	while (rose_node != NULL) {
  		if ((rose_node->mask == rose_route->mask) &&
  		    (rosecmpm(&rose_route->address, &rose_node->address,

  			      rose_route->mask) == 0))

  			break;
  		rose_node = rose_node->next;
  	}
  
  	if (rose_node != NULL && rose_node->loopback) {
  		res = -EINVAL;
  		goto out;
  	}
  
  	rose_neigh = rose_neigh_list;
  	while (rose_neigh != NULL) {

  		if (ax25cmp(&rose_route->neighbour,
  			    &rose_neigh->callsign) == 0 &&
  		    rose_neigh->dev == dev)

  			break;
  		rose_neigh = rose_neigh->next;
  	}
  
  	if (rose_neigh == NULL) {
  		rose_neigh = kmalloc(sizeof(*rose_neigh), GFP_ATOMIC);
  		if (rose_neigh == NULL) {
  			res = -ENOMEM;
  			goto out;
  		}
  
  		rose_neigh->callsign  = rose_route->neighbour;
  		rose_neigh->digipeat  = NULL;
  		rose_neigh->ax25      = NULL;
  		rose_neigh->dev       = dev;
  		rose_neigh->count     = 0;
  		rose_neigh->use       = 0;
  		rose_neigh->dce_mode  = 0;
  		rose_neigh->loopback  = 0;
  		rose_neigh->number    = rose_neigh_no++;
  		rose_neigh->restarted = 0;
  
  		skb_queue_head_init(&rose_neigh->queue);

  		timer_setup(&rose_neigh->ftimer, NULL, 0);
  		timer_setup(&rose_neigh->t0timer, NULL, 0);

  
  		if (rose_route->ndigis != 0) {

  			rose_neigh->digipeat =
  				kmalloc(sizeof(ax25_digi), GFP_ATOMIC);
  			if (rose_neigh->digipeat == NULL) {

  				kfree(rose_neigh);
  				res = -ENOMEM;
  				goto out;
  			}
  
  			rose_neigh->digipeat->ndigi      = rose_route->ndigis;
  			rose_neigh->digipeat->lastrepeat = -1;
  
  			for (i = 0; i < rose_route->ndigis; i++) {
  				rose_neigh->digipeat->calls[i]    =
  					rose_route->digipeaters[i];
  				rose_neigh->digipeat->repeated[i] = 0;
  			}
  		}
  
  		rose_neigh->next = rose_neigh_list;
  		rose_neigh_list  = rose_neigh;
  	}
  
  	/*
  	 * This is a new node to be inserted into the list. Find where it needs
  	 * to be inserted into the list, and insert it. We want to be sure
  	 * to order the list in descending order of mask size to ensure that
  	 * later when we are searching this list the first match will be the
  	 * best match.
  	 */
  	if (rose_node == NULL) {
  		rose_tmpn = rose_node_list;
  		rose_tmpp = NULL;
  
  		while (rose_tmpn != NULL) {
  			if (rose_tmpn->mask > rose_route->mask) {
  				rose_tmpp = rose_tmpn;
  				rose_tmpn = rose_tmpn->next;
  			} else {
  				break;
  			}
  		}
  
  		/* create new node */
  		rose_node = kmalloc(sizeof(*rose_node), GFP_ATOMIC);
  		if (rose_node == NULL) {
  			res = -ENOMEM;
  			goto out;
  		}
  
  		rose_node->address      = rose_route->address;
  		rose_node->mask         = rose_route->mask;
  		rose_node->count        = 1;
  		rose_node->loopback     = 0;
  		rose_node->neighbour[0] = rose_neigh;
  
  		if (rose_tmpn == NULL) {
  			if (rose_tmpp == NULL) {	/* Empty list */
  				rose_node_list  = rose_node;
  				rose_node->next = NULL;
  			} else {
  				rose_tmpp->next = rose_node;
  				rose_node->next = NULL;
  			}
  		} else {
  			if (rose_tmpp == NULL) {	/* 1st node */
  				rose_node->next = rose_node_list;
  				rose_node_list  = rose_node;
  			} else {
  				rose_tmpp->next = rose_node;
  				rose_node->next = rose_tmpn;
  			}
  		}
  		rose_neigh->count++;
  
  		goto out;
  	}
  
  	/* We have space, slot it in */
  	if (rose_node->count < 3) {
  		rose_node->neighbour[rose_node->count] = rose_neigh;
  		rose_node->count++;
  		rose_neigh->count++;
  	}
  
  out:
  	spin_unlock_bh(&rose_neigh_list_lock);
  	spin_unlock_bh(&rose_node_list_lock);
  
  	return res;
  }
  
  /*
   * Caller is holding rose_node_list_lock.
   */
  static void rose_remove_node(struct rose_node *rose_node)
  {
  	struct rose_node *s;
  
  	if ((s = rose_node_list) == rose_node) {
  		rose_node_list = rose_node->next;
  		kfree(rose_node);
  		return;
  	}
  
  	while (s != NULL && s->next != NULL) {
  		if (s->next == rose_node) {
  			s->next = rose_node->next;
  			kfree(rose_node);
  			return;
  		}
  
  		s = s->next;
  	}
  }
  
  /*
   * Caller is holding rose_neigh_list_lock.
   */
  static void rose_remove_neigh(struct rose_neigh *rose_neigh)
  {
  	struct rose_neigh *s;
  
  	rose_stop_ftimer(rose_neigh);
  	rose_stop_t0timer(rose_neigh);
  
  	skb_queue_purge(&rose_neigh->queue);

  	if ((s = rose_neigh_list) == rose_neigh) {
  		rose_neigh_list = rose_neigh->next;

  		if (rose_neigh->ax25)
  			ax25_cb_put(rose_neigh->ax25);

  		kfree(rose_neigh->digipeat);

  		kfree(rose_neigh);
  		return;
  	}
  
  	while (s != NULL && s->next != NULL) {
  		if (s->next == rose_neigh) {
  			s->next = rose_neigh->next;

  			if (rose_neigh->ax25)
  				ax25_cb_put(rose_neigh->ax25);

  			kfree(rose_neigh->digipeat);

  			kfree(rose_neigh);
  			return;
  		}
  
  		s = s->next;
  	}

  }
  
  /*
   * Caller is holding rose_route_list_lock.
   */
  static void rose_remove_route(struct rose_route *rose_route)
  {
  	struct rose_route *s;
  
  	if (rose_route->neigh1 != NULL)
  		rose_route->neigh1->use--;
  
  	if (rose_route->neigh2 != NULL)
  		rose_route->neigh2->use--;
  
  	if ((s = rose_route_list) == rose_route) {
  		rose_route_list = rose_route->next;
  		kfree(rose_route);
  		return;
  	}
  
  	while (s != NULL && s->next != NULL) {
  		if (s->next == rose_route) {
  			s->next = rose_route->next;
  			kfree(rose_route);
  			return;
  		}
  
  		s = s->next;
  	}
  }
  
  /*
   *	"Delete" a node. Strictly speaking remove a route to a node. The node
   *	is only deleted if no routes are left to it.
   */
  static int rose_del_node(struct rose_route_struct *rose_route,
  	struct net_device *dev)
  {
  	struct rose_node  *rose_node;
  	struct rose_neigh *rose_neigh;
  	int i, err = 0;
  
  	spin_lock_bh(&rose_node_list_lock);
  	spin_lock_bh(&rose_neigh_list_lock);
  
  	rose_node = rose_node_list;
  	while (rose_node != NULL) {
  		if ((rose_node->mask == rose_route->mask) &&
  		    (rosecmpm(&rose_route->address, &rose_node->address,

  			      rose_route->mask) == 0))

  			break;
  		rose_node = rose_node->next;
  	}
  
  	if (rose_node == NULL || rose_node->loopback) {
  		err = -EINVAL;
  		goto out;
  	}
  
  	rose_neigh = rose_neigh_list;
  	while (rose_neigh != NULL) {

  		if (ax25cmp(&rose_route->neighbour,
  			    &rose_neigh->callsign) == 0 &&
  		    rose_neigh->dev == dev)

  			break;
  		rose_neigh = rose_neigh->next;
  	}
  
  	if (rose_neigh == NULL) {
  		err = -EINVAL;
  		goto out;
  	}
  
  	for (i = 0; i < rose_node->count; i++) {
  		if (rose_node->neighbour[i] == rose_neigh) {
  			rose_neigh->count--;
  
  			if (rose_neigh->count == 0 && rose_neigh->use == 0)
  				rose_remove_neigh(rose_neigh);
  
  			rose_node->count--;
  
  			if (rose_node->count == 0) {
  				rose_remove_node(rose_node);
  			} else {
  				switch (i) {
  				case 0:
  					rose_node->neighbour[0] =
  						rose_node->neighbour[1];

  					fallthrough;

  				case 1:
  					rose_node->neighbour[1] =
  						rose_node->neighbour[2];
  				case 2:
  					break;
  				}
  			}
  			goto out;
  		}
  	}
  	err = -EINVAL;
  
  out:
  	spin_unlock_bh(&rose_neigh_list_lock);
  	spin_unlock_bh(&rose_node_list_lock);
  
  	return err;
  }
  
  /*
   *	Add the loopback neighbour.
   */

  void rose_add_loopback_neigh(void)

  {

  	struct rose_neigh *sn;
  
  	rose_loopback_neigh = kmalloc(sizeof(struct rose_neigh), GFP_KERNEL);
  	if (!rose_loopback_neigh)
  		return;
  	sn = rose_loopback_neigh;

  	sn->callsign  = null_ax25_address;
  	sn->digipeat  = NULL;
  	sn->ax25      = NULL;
  	sn->dev       = NULL;
  	sn->count     = 0;
  	sn->use       = 0;
  	sn->dce_mode  = 1;
  	sn->loopback  = 1;
  	sn->number    = rose_neigh_no++;
  	sn->restarted = 1;

  	skb_queue_head_init(&sn->queue);

  	timer_setup(&sn->ftimer, NULL, 0);
  	timer_setup(&sn->t0timer, NULL, 0);

  
  	spin_lock_bh(&rose_neigh_list_lock);

  	sn->next = rose_neigh_list;
  	rose_neigh_list           = sn;

  	spin_unlock_bh(&rose_neigh_list_lock);

  }
  
  /*
   *	Add a loopback node.
   */
  int rose_add_loopback_node(rose_address *address)
  {
  	struct rose_node *rose_node;

  	int err = 0;

  
  	spin_lock_bh(&rose_node_list_lock);
  
  	rose_node = rose_node_list;
  	while (rose_node != NULL) {
  		if ((rose_node->mask == 10) &&
  		     (rosecmpm(address, &rose_node->address, 10) == 0) &&
  		     rose_node->loopback)
  			break;
  		rose_node = rose_node->next;
  	}
  
  	if (rose_node != NULL)
  		goto out;
  
  	if ((rose_node = kmalloc(sizeof(*rose_node), GFP_ATOMIC)) == NULL) {
  		err = -ENOMEM;
  		goto out;
  	}
  
  	rose_node->address      = *address;
  	rose_node->mask         = 10;
  	rose_node->count        = 1;
  	rose_node->loopback     = 1;

  	rose_node->neighbour[0] = rose_loopback_neigh;

  
  	/* Insert at the head of list. Address is always mask=10 */
  	rose_node->next = rose_node_list;
  	rose_node_list  = rose_node;

  	rose_loopback_neigh->count++;

  
  out:
  	spin_unlock_bh(&rose_node_list_lock);

  	return err;

  }
  
  /*
   *	Delete a loopback node.
   */
  void rose_del_loopback_node(rose_address *address)
  {
  	struct rose_node *rose_node;
  
  	spin_lock_bh(&rose_node_list_lock);
  
  	rose_node = rose_node_list;
  	while (rose_node != NULL) {
  		if ((rose_node->mask == 10) &&
  		    (rosecmpm(address, &rose_node->address, 10) == 0) &&
  		    rose_node->loopback)
  			break;
  		rose_node = rose_node->next;
  	}
  
  	if (rose_node == NULL)
  		goto out;
  
  	rose_remove_node(rose_node);

  	rose_loopback_neigh->count--;

  
  out:
  	spin_unlock_bh(&rose_node_list_lock);
  }
  
  /*
   *	A device has been removed. Remove its routes and neighbours.
   */
  void rose_rt_device_down(struct net_device *dev)
  {
  	struct rose_neigh *s, *rose_neigh;
  	struct rose_node  *t, *rose_node;
  	int i;
  
  	spin_lock_bh(&rose_node_list_lock);
  	spin_lock_bh(&rose_neigh_list_lock);
  	rose_neigh = rose_neigh_list;
  	while (rose_neigh != NULL) {
  		s          = rose_neigh;
  		rose_neigh = rose_neigh->next;
  
  		if (s->dev != dev)
  			continue;
  
  		rose_node = rose_node_list;
  
  		while (rose_node != NULL) {
  			t         = rose_node;
  			rose_node = rose_node->next;
  
  			for (i = 0; i < t->count; i++) {
  				if (t->neighbour[i] != s)
  					continue;
  
  				t->count--;
  
  				switch (i) {
  				case 0:
  					t->neighbour[0] = t->neighbour[1];

  					fallthrough;

  				case 1:
  					t->neighbour[1] = t->neighbour[2];
  				case 2:
  					break;
  				}
  			}
  
  			if (t->count <= 0)
  				rose_remove_node(t);
  		}
  
  		rose_remove_neigh(s);
  	}
  	spin_unlock_bh(&rose_neigh_list_lock);
  	spin_unlock_bh(&rose_node_list_lock);
  }
  
  #if 0 /* Currently unused */
  /*
   *	A device has been removed. Remove its links.
   */
  void rose_route_device_down(struct net_device *dev)
  {
  	struct rose_route *s, *rose_route;
  
  	spin_lock_bh(&rose_route_list_lock);
  	rose_route = rose_route_list;
  	while (rose_route != NULL) {
  		s          = rose_route;
  		rose_route = rose_route->next;
  
  		if (s->neigh1->dev == dev || s->neigh2->dev == dev)
  			rose_remove_route(s);
  	}
  	spin_unlock_bh(&rose_route_list_lock);
  }
  #endif
  
  /*
   *	Clear all nodes and neighbours out, except for neighbours with
   *	active connections going through them.
   *  Do not clear loopback neighbour and nodes.
   */
  static int rose_clear_routes(void)
  {
  	struct rose_neigh *s, *rose_neigh;
  	struct rose_node  *t, *rose_node;
  
  	spin_lock_bh(&rose_node_list_lock);
  	spin_lock_bh(&rose_neigh_list_lock);
  
  	rose_neigh = rose_neigh_list;
  	rose_node  = rose_node_list;
  
  	while (rose_node != NULL) {
  		t         = rose_node;
  		rose_node = rose_node->next;
  		if (!t->loopback)
  			rose_remove_node(t);
  	}
  
  	while (rose_neigh != NULL) {
  		s          = rose_neigh;
  		rose_neigh = rose_neigh->next;
  
  		if (s->use == 0 && !s->loopback) {
  			s->count = 0;
  			rose_remove_neigh(s);
  		}
  	}
  
  	spin_unlock_bh(&rose_neigh_list_lock);
  	spin_unlock_bh(&rose_node_list_lock);
  
  	return 0;
  }
  
  /*
   *	Check that the device given is a valid AX.25 interface that is "up".

   * 	called with RTNL

   */

  static struct net_device *rose_ax25_dev_find(char *devname)

  {
  	struct net_device *dev;

  	if ((dev = __dev_get_by_name(&init_net, devname)) == NULL)

  		return NULL;
  
  	if ((dev->flags & IFF_UP) && dev->type == ARPHRD_AX25)
  		return dev;

  	return NULL;
  }
  
  /*
   *	Find the first active ROSE device, usually "rose0".
   */
  struct net_device *rose_dev_first(void)
  {
  	struct net_device *dev, *first = NULL;

  	rcu_read_lock();
  	for_each_netdev_rcu(&init_net, dev) {

  		if ((dev->flags & IFF_UP) && dev->type == ARPHRD_ROSE)
  			if (first == NULL || strncmp(dev->name, first->name, 3) < 0)
  				first = dev;
  	}

  	rcu_read_unlock();

  
  	return first;
  }
  
  /*
   *	Find the ROSE device for the given address.
   */
  struct net_device *rose_dev_get(rose_address *addr)
  {
  	struct net_device *dev;

  	rcu_read_lock();
  	for_each_netdev_rcu(&init_net, dev) {

  		if ((dev->flags & IFF_UP) && dev->type == ARPHRD_ROSE && rosecmp(addr, (rose_address *)dev->dev_addr) == 0) {
  			dev_hold(dev);
  			goto out;
  		}
  	}

  	dev = NULL;

  out:

  	rcu_read_unlock();

  	return dev;
  }
  
  static int rose_dev_exists(rose_address *addr)
  {
  	struct net_device *dev;

  	rcu_read_lock();
  	for_each_netdev_rcu(&init_net, dev) {

  		if ((dev->flags & IFF_UP) && dev->type == ARPHRD_ROSE && rosecmp(addr, (rose_address *)dev->dev_addr) == 0)
  			goto out;
  	}

  	dev = NULL;

  out:

  	rcu_read_unlock();

  	return dev != NULL;
  }
  
  
  
  
  struct rose_route *rose_route_free_lci(unsigned int lci, struct rose_neigh *neigh)
  {
  	struct rose_route *rose_route;
  
  	for (rose_route = rose_route_list; rose_route != NULL; rose_route = rose_route->next)
  		if ((rose_route->neigh1 == neigh && rose_route->lci1 == lci) ||
  		    (rose_route->neigh2 == neigh && rose_route->lci2 == lci))
  			return rose_route;
  
  	return NULL;
  }
  
  /*

   *	Find a neighbour or a route given a ROSE address.

   */
  struct rose_neigh *rose_get_neigh(rose_address *addr, unsigned char *cause,

  	unsigned char *diagnostic, int route_frame)

  {
  	struct rose_neigh *res = NULL;
  	struct rose_node *node;
  	int failed = 0;
  	int i;

  	if (!route_frame) spin_lock_bh(&rose_node_list_lock);

  	for (node = rose_node_list; node != NULL; node = node->next) {
  		if (rosecmpm(addr, &node->address, node->mask) == 0) {
  			for (i = 0; i < node->count; i++) {

  				if (node->neighbour[i]->restarted) {
  					res = node->neighbour[i];
  					goto out;

  				}

  			}
  		}
  	}
  	if (!route_frame) { /* connect request */
  		for (node = rose_node_list; node != NULL; node = node->next) {
  			if (rosecmpm(addr, &node->address, node->mask) == 0) {
  				for (i = 0; i < node->count; i++) {

  					if (!rose_ftimer_running(node->neighbour[i])) {
  						res = node->neighbour[i];
  						goto out;

  					}
  					failed = 1;

  				}

  			}

  		}
  	}
  
  	if (failed) {
  		*cause      = ROSE_OUT_OF_ORDER;
  		*diagnostic = 0;
  	} else {
  		*cause      = ROSE_NOT_OBTAINABLE;
  		*diagnostic = 0;
  	}
  
  out:

  	if (!route_frame) spin_unlock_bh(&rose_node_list_lock);

  	return res;
  }
  
  /*
   *	Handle the ioctls that control the routing functions.
   */
  int rose_rt_ioctl(unsigned int cmd, void __user *arg)
  {
  	struct rose_route_struct rose_route;
  	struct net_device *dev;
  	int err;
  
  	switch (cmd) {
  	case SIOCADDRT:
  		if (copy_from_user(&rose_route, arg, sizeof(struct rose_route_struct)))
  			return -EFAULT;

  		if ((dev = rose_ax25_dev_find(rose_route.device)) == NULL)

  			return -EINVAL;

  		if (rose_dev_exists(&rose_route.address)) /* Can't add routes to ourself */

  			return -EINVAL;

  		if (rose_route.mask > 10) /* Mask can't be more than 10 digits */
  			return -EINVAL;

  		if (rose_route.ndigis > AX25_MAX_DIGIS)

  			return -EINVAL;
  		err = rose_add_node(&rose_route, dev);

  		return err;
  
  	case SIOCDELRT:
  		if (copy_from_user(&rose_route, arg, sizeof(struct rose_route_struct)))
  			return -EFAULT;

  		if ((dev = rose_ax25_dev_find(rose_route.device)) == NULL)

  			return -EINVAL;
  		err = rose_del_node(&rose_route, dev);

  		return err;
  
  	case SIOCRSCLRRT:
  		return rose_clear_routes();
  
  	default:
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static void rose_del_route_by_neigh(struct rose_neigh *rose_neigh)
  {
  	struct rose_route *rose_route, *s;
  
  	rose_neigh->restarted = 0;
  
  	rose_stop_t0timer(rose_neigh);
  	rose_start_ftimer(rose_neigh);
  
  	skb_queue_purge(&rose_neigh->queue);
  
  	spin_lock_bh(&rose_route_list_lock);
  
  	rose_route = rose_route_list;
  
  	while (rose_route != NULL) {
  		if ((rose_route->neigh1 == rose_neigh && rose_route->neigh2 == rose_neigh) ||
  		    (rose_route->neigh1 == rose_neigh && rose_route->neigh2 == NULL)       ||
  		    (rose_route->neigh2 == rose_neigh && rose_route->neigh1 == NULL)) {
  			s = rose_route->next;
  			rose_remove_route(rose_route);
  			rose_route = s;
  			continue;
  		}
  
  		if (rose_route->neigh1 == rose_neigh) {
  			rose_route->neigh1->use--;
  			rose_route->neigh1 = NULL;
  			rose_transmit_clear_request(rose_route->neigh2, rose_route->lci2, ROSE_OUT_OF_ORDER, 0);
  		}
  
  		if (rose_route->neigh2 == rose_neigh) {
  			rose_route->neigh2->use--;
  			rose_route->neigh2 = NULL;
  			rose_transmit_clear_request(rose_route->neigh1, rose_route->lci1, ROSE_OUT_OF_ORDER, 0);
  		}
  
  		rose_route = rose_route->next;
  	}
  	spin_unlock_bh(&rose_route_list_lock);
  }
  
  /*
   * 	A level 2 link has timed out, therefore it appears to be a poor link,
   *	then don't use that neighbour until it is reset. Blow away all through
   *	routes and connections using this route.
   */
  void rose_link_failed(ax25_cb *ax25, int reason)
  {
  	struct rose_neigh *rose_neigh;
  
  	spin_lock_bh(&rose_neigh_list_lock);
  	rose_neigh = rose_neigh_list;
  	while (rose_neigh != NULL) {
  		if (rose_neigh->ax25 == ax25)
  			break;
  		rose_neigh = rose_neigh->next;
  	}
  
  	if (rose_neigh != NULL) {
  		rose_neigh->ax25 = NULL;

  		ax25_cb_put(ax25);

  
  		rose_del_route_by_neigh(rose_neigh);
  		rose_kill_by_neigh(rose_neigh);
  	}
  	spin_unlock_bh(&rose_neigh_list_lock);
  }
  
  /*
   * 	A device has been "downed" remove its link status. Blow away all
   *	through routes and connections that use this device.
   */
  void rose_link_device_down(struct net_device *dev)
  {
  	struct rose_neigh *rose_neigh;
  
  	for (rose_neigh = rose_neigh_list; rose_neigh != NULL; rose_neigh = rose_neigh->next) {
  		if (rose_neigh->dev == dev) {
  			rose_del_route_by_neigh(rose_neigh);
  			rose_kill_by_neigh(rose_neigh);
  		}
  	}
  }
  
  /*
   *	Route a frame to an appropriate AX.25 connection.

   *	A NULL ax25_cb indicates an internally generated frame.

   */
  int rose_route_frame(struct sk_buff *skb, ax25_cb *ax25)
  {
  	struct rose_neigh *rose_neigh, *new_neigh;
  	struct rose_route *rose_route;
  	struct rose_facilities_struct facilities;
  	rose_address *src_addr, *dest_addr;
  	struct sock *sk;
  	unsigned short frametype;
  	unsigned int lci, new_lci;
  	unsigned char cause, diagnostic;
  	struct net_device *dev;

  	int res = 0;

  	char buf[11];

  	if (skb->len < ROSE_MIN_LEN)
  		return res;

  
  	if (!ax25)
  		return rose_loopback_queue(skb, NULL);

  	frametype = skb->data[2];
  	lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);

  	if (frametype == ROSE_CALL_REQUEST &&
  	    (skb->len <= ROSE_CALL_REQ_FACILITIES_OFF ||
  	     skb->data[ROSE_CALL_REQ_ADDR_LEN_OFF] !=
  	     ROSE_CALL_REQ_ADDR_LEN_VAL))
  		return res;
  	src_addr  = (rose_address *)(skb->data + ROSE_CALL_REQ_SRC_ADDR_OFF);
  	dest_addr = (rose_address *)(skb->data + ROSE_CALL_REQ_DEST_ADDR_OFF);

  	spin_lock_bh(&rose_neigh_list_lock);
  	spin_lock_bh(&rose_route_list_lock);
  
  	rose_neigh = rose_neigh_list;
  	while (rose_neigh != NULL) {
  		if (ax25cmp(&ax25->dest_addr, &rose_neigh->callsign) == 0 &&
  		    ax25->ax25_dev->dev == rose_neigh->dev)
  			break;
  		rose_neigh = rose_neigh->next;
  	}
  
  	if (rose_neigh == NULL) {
  		printk("rose_route : unknown neighbour or device %s
  ",

  		       ax2asc(buf, &ax25->dest_addr));

  		goto out;
  	}
  
  	/*
  	 *	Obviously the link is working, halt the ftimer.
  	 */
  	rose_stop_ftimer(rose_neigh);
  
  	/*
  	 *	LCI of zero is always for us, and its always a restart
  	 * 	frame.
  	 */
  	if (lci == 0) {
  		rose_link_rx_restart(skb, rose_neigh, frametype);
  		goto out;
  	}
  
  	/*
  	 *	Find an existing socket.
  	 */
  	if ((sk = rose_find_socket(lci, rose_neigh)) != NULL) {
  		if (frametype == ROSE_CALL_REQUEST) {
  			struct rose_sock *rose = rose_sk(sk);
  
  			/* Remove an existing unused socket */
  			rose_clear_queues(sk);
  			rose->cause	 = ROSE_NETWORK_CONGESTION;
  			rose->diagnostic = 0;
  			rose->neighbour->use--;
  			rose->neighbour	 = NULL;
  			rose->lci	 = 0;
  			rose->state	 = ROSE_STATE_0;
  			sk->sk_state	 = TCP_CLOSE;
  			sk->sk_err	 = 0;
  			sk->sk_shutdown	 |= SEND_SHUTDOWN;
  			if (!sock_flag(sk, SOCK_DEAD)) {
  				sk->sk_state_change(sk);
  				sock_set_flag(sk, SOCK_DEAD);
  			}
  		}
  		else {

  			skb_reset_transport_header(skb);

  			res = rose_process_rx_frame(sk, skb);
  			goto out;
  		}
  	}
  
  	/*
  	 *	Is is a Call Request and is it for us ?
  	 */
  	if (frametype == ROSE_CALL_REQUEST)
  		if ((dev = rose_dev_get(dest_addr)) != NULL) {
  			res = rose_rx_call_request(skb, dev, rose_neigh, lci);
  			dev_put(dev);
  			goto out;
  		}
  
  	if (!sysctl_rose_routing_control) {
  		rose_transmit_clear_request(rose_neigh, lci, ROSE_NOT_OBTAINABLE, 0);
  		goto out;
  	}
  
  	/*
  	 *	Route it to the next in line if we have an entry for it.
  	 */
  	rose_route = rose_route_list;
  	while (rose_route != NULL) {
  		if (rose_route->lci1 == lci &&
  		    rose_route->neigh1 == rose_neigh) {
  			if (frametype == ROSE_CALL_REQUEST) {
  				/* F6FBB - Remove an existing unused route */
  				rose_remove_route(rose_route);
  				break;
  			} else if (rose_route->neigh2 != NULL) {
  				skb->data[0] &= 0xF0;
  				skb->data[0] |= (rose_route->lci2 >> 8) & 0x0F;
  				skb->data[1]  = (rose_route->lci2 >> 0) & 0xFF;
  				rose_transmit_link(skb, rose_route->neigh2);
  				if (frametype == ROSE_CLEAR_CONFIRMATION)
  					rose_remove_route(rose_route);
  				res = 1;
  				goto out;
  			} else {
  				if (frametype == ROSE_CLEAR_CONFIRMATION)
  					rose_remove_route(rose_route);
  				goto out;
  			}
  		}
  		if (rose_route->lci2 == lci &&
  		    rose_route->neigh2 == rose_neigh) {
  			if (frametype == ROSE_CALL_REQUEST) {
  				/* F6FBB - Remove an existing unused route */
  				rose_remove_route(rose_route);
  				break;
  			} else if (rose_route->neigh1 != NULL) {
  				skb->data[0] &= 0xF0;
  				skb->data[0] |= (rose_route->lci1 >> 8) & 0x0F;
  				skb->data[1]  = (rose_route->lci1 >> 0) & 0xFF;
  				rose_transmit_link(skb, rose_route->neigh1);
  				if (frametype == ROSE_CLEAR_CONFIRMATION)
  					rose_remove_route(rose_route);
  				res = 1;
  				goto out;
  			} else {
  				if (frametype == ROSE_CLEAR_CONFIRMATION)
  					rose_remove_route(rose_route);
  				goto out;
  			}
  		}
  		rose_route = rose_route->next;
  	}
  
  	/*
  	 *	We know that:
  	 *	1. The frame isn't for us,
  	 *	2. It isn't "owned" by any existing route.
  	 */

  	if (frametype != ROSE_CALL_REQUEST) {	/* XXX */

  		res = 0;

  		goto out;
  	}

  	memset(&facilities, 0x00, sizeof(struct rose_facilities_struct));

  	if (!rose_parse_facilities(skb->data + ROSE_CALL_REQ_FACILITIES_OFF,
  				   skb->len - ROSE_CALL_REQ_FACILITIES_OFF,
  				   &facilities)) {

  		rose_transmit_clear_request(rose_neigh, lci, ROSE_INVALID_FACILITY, 76);
  		goto out;
  	}
  
  	/*
  	 *	Check for routing loops.
  	 */
  	rose_route = rose_route_list;
  	while (rose_route != NULL) {
  		if (rose_route->rand == facilities.rand &&
  		    rosecmp(src_addr, &rose_route->src_addr) == 0 &&
  		    ax25cmp(&facilities.dest_call, &rose_route->src_call) == 0 &&
  		    ax25cmp(&facilities.source_call, &rose_route->dest_call) == 0) {
  			rose_transmit_clear_request(rose_neigh, lci, ROSE_NOT_OBTAINABLE, 120);
  			goto out;
  		}
  		rose_route = rose_route->next;
  	}

  	if ((new_neigh = rose_get_neigh(dest_addr, &cause, &diagnostic, 1)) == NULL) {

  		rose_transmit_clear_request(rose_neigh, lci, cause, diagnostic);
  		goto out;
  	}
  
  	if ((new_lci = rose_new_lci(new_neigh)) == 0) {
  		rose_transmit_clear_request(rose_neigh, lci, ROSE_NETWORK_CONGESTION, 71);
  		goto out;
  	}
  
  	if ((rose_route = kmalloc(sizeof(*rose_route), GFP_ATOMIC)) == NULL) {
  		rose_transmit_clear_request(rose_neigh, lci, ROSE_NETWORK_CONGESTION, 120);
  		goto out;
  	}
  
  	rose_route->lci1      = lci;
  	rose_route->src_addr  = *src_addr;
  	rose_route->dest_addr = *dest_addr;
  	rose_route->src_call  = facilities.dest_call;
  	rose_route->dest_call = facilities.source_call;
  	rose_route->rand      = facilities.rand;
  	rose_route->neigh1    = rose_neigh;
  	rose_route->lci2      = new_lci;
  	rose_route->neigh2    = new_neigh;
  
  	rose_route->neigh1->use++;
  	rose_route->neigh2->use++;
  
  	rose_route->next = rose_route_list;
  	rose_route_list  = rose_route;
  
  	skb->data[0] &= 0xF0;
  	skb->data[0] |= (rose_route->lci2 >> 8) & 0x0F;
  	skb->data[1]  = (rose_route->lci2 >> 0) & 0xFF;
  
  	rose_transmit_link(skb, rose_route->neigh2);
  	res = 1;
  
  out:
  	spin_unlock_bh(&rose_route_list_lock);
  	spin_unlock_bh(&rose_neigh_list_lock);

  
  	return res;
  }
  
  #ifdef CONFIG_PROC_FS
  
  static void *rose_node_start(struct seq_file *seq, loff_t *pos)

  	__acquires(rose_node_list_lock)

  {
  	struct rose_node *rose_node;
  	int i = 1;

  	spin_lock_bh(&rose_node_list_lock);

  	if (*pos == 0)
  		return SEQ_START_TOKEN;

  	for (rose_node = rose_node_list; rose_node && i < *pos;

  	     rose_node = rose_node->next, ++i);
  
  	return (i == *pos) ? rose_node : NULL;
  }
  
  static void *rose_node_next(struct seq_file *seq, void *v, loff_t *pos)
  {
  	++*pos;

  
  	return (v == SEQ_START_TOKEN) ? rose_node_list

  		: ((struct rose_node *)v)->next;
  }
  
  static void rose_node_stop(struct seq_file *seq, void *v)

  	__releases(rose_node_list_lock)

  {

  	spin_unlock_bh(&rose_node_list_lock);

  }
  
  static int rose_node_show(struct seq_file *seq, void *v)
  {

  	char rsbuf[11];

  	int i;
  
  	if (v == SEQ_START_TOKEN)
  		seq_puts(seq, "address    mask n neigh neigh neigh
  ");
  	else {
  		const struct rose_node *rose_node = v;
  		/* if (rose_node->loopback) {
  			seq_printf(seq, "%-10s %04d 1 loopback
  ",

  				   rose2asc(rsbuf, &rose_node->address),
  				   rose_node->mask);

  		} else { */
  			seq_printf(seq, "%-10s %04d %d",

  				   rose2asc(rsbuf, &rose_node->address),
  				   rose_node->mask,
  				   rose_node->count);

  
  			for (i = 0; i < rose_node->count; i++)
  				seq_printf(seq, " %05d",
  					rose_node->neighbour[i]->number);
  
  			seq_puts(seq, "
  ");
  		/* } */
  	}
  	return 0;
  }

  const struct seq_operations rose_node_seqops = {

  	.start = rose_node_start,
  	.next = rose_node_next,
  	.stop = rose_node_stop,
  	.show = rose_node_show,
  };

  static void *rose_neigh_start(struct seq_file *seq, loff_t *pos)

  	__acquires(rose_neigh_list_lock)

  {
  	struct rose_neigh *rose_neigh;
  	int i = 1;
  
  	spin_lock_bh(&rose_neigh_list_lock);
  	if (*pos == 0)
  		return SEQ_START_TOKEN;

  	for (rose_neigh = rose_neigh_list; rose_neigh && i < *pos;

  	     rose_neigh = rose_neigh->next, ++i);
  
  	return (i == *pos) ? rose_neigh : NULL;
  }
  
  static void *rose_neigh_next(struct seq_file *seq, void *v, loff_t *pos)
  {
  	++*pos;

  
  	return (v == SEQ_START_TOKEN) ? rose_neigh_list

  		: ((struct rose_neigh *)v)->next;
  }
  
  static void rose_neigh_stop(struct seq_file *seq, void *v)

  	__releases(rose_neigh_list_lock)

  {
  	spin_unlock_bh(&rose_neigh_list_lock);
  }
  
  static int rose_neigh_show(struct seq_file *seq, void *v)
  {

  	char buf[11];

  	int i;
  
  	if (v == SEQ_START_TOKEN)

  		seq_puts(seq,

  			 "addr  callsign  dev  count use mode restart  t0  tf digipeaters
  ");
  	else {
  		struct rose_neigh *rose_neigh = v;
  
  		/* if (!rose_neigh->loopback) { */
  		seq_printf(seq, "%05d %-9s %-4s   %3d %3d  %3s     %3s %3lu %3lu",
  			   rose_neigh->number,

  			   (rose_neigh->loopback) ? "RSLOOP-0" : ax2asc(buf, &rose_neigh->callsign),

  			   rose_neigh->dev ? rose_neigh->dev->name : "???",
  			   rose_neigh->count,
  			   rose_neigh->use,
  			   (rose_neigh->dce_mode) ? "DCE" : "DTE",
  			   (rose_neigh->restarted) ? "yes" : "no",
  			   ax25_display_timer(&rose_neigh->t0timer) / HZ,
  			   ax25_display_timer(&rose_neigh->ftimer)  / HZ);
  
  		if (rose_neigh->digipeat != NULL) {
  			for (i = 0; i < rose_neigh->digipeat->ndigi; i++)

  				seq_printf(seq, " %s", ax2asc(buf, &rose_neigh->digipeat->calls[i]));

  		}
  
  		seq_puts(seq, "
  ");
  	}
  	return 0;
  }

  const struct seq_operations rose_neigh_seqops = {

  	.start = rose_neigh_start,
  	.next = rose_neigh_next,
  	.stop = rose_neigh_stop,
  	.show = rose_neigh_show,
  };

  static void *rose_route_start(struct seq_file *seq, loff_t *pos)

  	__acquires(rose_route_list_lock)

  {
  	struct rose_route *rose_route;
  	int i = 1;
  
  	spin_lock_bh(&rose_route_list_lock);
  	if (*pos == 0)
  		return SEQ_START_TOKEN;

  	for (rose_route = rose_route_list; rose_route && i < *pos;

  	     rose_route = rose_route->next, ++i);
  
  	return (i == *pos) ? rose_route : NULL;
  }
  
  static void *rose_route_next(struct seq_file *seq, void *v, loff_t *pos)
  {
  	++*pos;

  
  	return (v == SEQ_START_TOKEN) ? rose_route_list

  		: ((struct rose_route *)v)->next;
  }
  
  static void rose_route_stop(struct seq_file *seq, void *v)

  	__releases(rose_route_list_lock)

  {
  	spin_unlock_bh(&rose_route_list_lock);
  }
  
  static int rose_route_show(struct seq_file *seq, void *v)
  {

  	char buf[11], rsbuf[11];

  	if (v == SEQ_START_TOKEN)

  		seq_puts(seq,

  			 "lci  address     callsign   neigh  <-> lci  address     callsign   neigh
  ");
  	else {
  		struct rose_route *rose_route = v;

  		if (rose_route->neigh1)

  			seq_printf(seq,
  				   "%3.3X  %-10s  %-9s  %05d      ",
  				   rose_route->lci1,

  				   rose2asc(rsbuf, &rose_route->src_addr),

  				   ax2asc(buf, &rose_route->src_call),

  				   rose_route->neigh1->number);

  		else
  			seq_puts(seq,

  				 "000  *           *          00000      ");

  		if (rose_route->neigh2)

  			seq_printf(seq,
  				   "%3.3X  %-10s  %-9s  %05d
  ",

  				   rose_route->lci2,
  				   rose2asc(rsbuf, &rose_route->dest_addr),
  				   ax2asc(buf, &rose_route->dest_call),
  				   rose_route->neigh2->number);

  		 else

  			 seq_puts(seq,
  				  "000  *           *          00000
  ");
  		}
  	return 0;
  }

  struct seq_operations rose_route_seqops = {

  	.start = rose_route_start,
  	.next = rose_route_next,
  	.stop = rose_route_stop,
  	.show = rose_route_show,
  };

  #endif /* CONFIG_PROC_FS */
  
  /*
   *	Release all memory associated with ROSE routing structures.
   */
  void __exit rose_rt_free(void)
  {
  	struct rose_neigh *s, *rose_neigh = rose_neigh_list;
  	struct rose_node  *t, *rose_node  = rose_node_list;
  	struct rose_route *u, *rose_route = rose_route_list;
  
  	while (rose_neigh != NULL) {
  		s          = rose_neigh;
  		rose_neigh = rose_neigh->next;
  
  		rose_remove_neigh(s);
  	}
  
  	while (rose_node != NULL) {
  		t         = rose_node;
  		rose_node = rose_node->next;
  
  		rose_remove_node(t);
  	}
  
  	while (rose_route != NULL) {
  		u          = rose_route;
  		rose_route = rose_route->next;
  
  		rose_remove_route(u);
  	}
  }