/*
   *	This module:
   *		This module 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.
   *
   *	History
   *	03-01-2007	Added forwarding for x.25	Andrew Hendry
   */
  #include <linux/if_arp.h>
  #include <linux/init.h>

  #include <linux/slab.h>

  #include <net/x25.h>

  LIST_HEAD(x25_forward_list);

  DEFINE_RWLOCK(x25_forward_list_lock);
  
  int x25_forward_call(struct x25_address *dest_addr, struct x25_neigh *from,
  			struct sk_buff *skb, int lci)
  {
  	struct x25_route *rt;
  	struct x25_neigh *neigh_new = NULL;
  	struct list_head *entry;
  	struct x25_forward *x25_frwd, *new_frwd;
  	struct sk_buff *skbn;
  	short same_lci = 0;
  	int rc = 0;

  	if ((rt = x25_get_route(dest_addr)) == NULL)
  		goto out_no_route;

  	if ((neigh_new = x25_get_neigh(rt->dev)) == NULL) {

  		/* This shouldn't happen, if it occurs somehow

  		 * do something sensible

  		 */

  		goto out_put_route;
  	}

  	/* Avoid a loop. This is the normal exit path for a
  	 * system with only one x.25 iface and default route
  	 */
  	if (rt->dev == from->dev) {
  		goto out_put_nb;
  	}
  
  	/* Remote end sending a call request on an already

  	 * established LCI? It shouldn't happen, just in case..

  	 */
  	read_lock_bh(&x25_forward_list_lock);
  	list_for_each(entry, &x25_forward_list) {
  		x25_frwd = list_entry(entry, struct x25_forward, node);
  		if (x25_frwd->lci == lci) {
  			printk(KERN_WARNING "X.25: call request for lci which is already registered!, transmitting but not registering new pair
  ");
  			same_lci = 1;

  		}

  	}
  	read_unlock_bh(&x25_forward_list_lock);

  	/* Save the forwarding details for future traffic */
  	if (!same_lci){
  		if ((new_frwd = kmalloc(sizeof(struct x25_forward),
  						GFP_ATOMIC)) == NULL){
  			rc = -ENOMEM;

  			goto out_put_nb;
  		}

  		new_frwd->lci = lci;
  		new_frwd->dev1 = rt->dev;
  		new_frwd->dev2 = from->dev;
  		write_lock_bh(&x25_forward_list_lock);
  		list_add(&new_frwd->node, &x25_forward_list);
  		write_unlock_bh(&x25_forward_list_lock);
  	}
  
  	/* Forward the call request */
  	if ( (skbn = skb_clone(skb, GFP_ATOMIC)) == NULL){
  		goto out_put_nb;

  	}

  	x25_transmit_link(skbn, neigh_new);
  	rc = 1;

  
  
  out_put_nb:
  	x25_neigh_put(neigh_new);
  
  out_put_route:
  	x25_route_put(rt);

  
  out_no_route:

  	return rc;
  }
  
  
  int x25_forward_data(int lci, struct x25_neigh *from, struct sk_buff *skb) {
  
  	struct x25_forward *frwd;
  	struct list_head *entry;
  	struct net_device *peer = NULL;
  	struct x25_neigh *nb;
  	struct sk_buff *skbn;
  	int rc = 0;
  
  	read_lock_bh(&x25_forward_list_lock);
  	list_for_each(entry, &x25_forward_list) {
  		frwd = list_entry(entry, struct x25_forward, node);
  		if (frwd->lci == lci) {
  			/* The call is established, either side can send */
  			if (from->dev == frwd->dev1) {
  				peer = frwd->dev2;
  			} else {
  				peer = frwd->dev1;
  			}
  			break;
  		}
  	}
  	read_unlock_bh(&x25_forward_list_lock);
  
  	if ( (nb = x25_get_neigh(peer)) == NULL)
  		goto out;
  
  	if ( (skbn = pskb_copy(skb, GFP_ATOMIC)) == NULL){

  		goto output;

  
  	}
  	x25_transmit_link(skbn, nb);

  	rc = 1;

  output:
  	x25_neigh_put(nb);

  out:
  	return rc;
  }
  
  void x25_clear_forward_by_lci(unsigned int lci)
  {
  	struct x25_forward *fwd;
  	struct list_head *entry, *tmp;
  
  	write_lock_bh(&x25_forward_list_lock);
  
  	list_for_each_safe(entry, tmp, &x25_forward_list) {
  		fwd = list_entry(entry, struct x25_forward, node);
  		if (fwd->lci == lci) {
  			list_del(&fwd->node);
  			kfree(fwd);
  		}
  	}
  	write_unlock_bh(&x25_forward_list_lock);
  }
  
  
  void x25_clear_forward_by_dev(struct net_device *dev)
  {
  	struct x25_forward *fwd;
  	struct list_head *entry, *tmp;
  
  	write_lock_bh(&x25_forward_list_lock);
  
  	list_for_each_safe(entry, tmp, &x25_forward_list) {
  		fwd = list_entry(entry, struct x25_forward, node);
  		if ((fwd->dev1 == dev) || (fwd->dev2 == dev)){
  			list_del(&fwd->node);
  			kfree(fwd);
  		}
  	}
  	write_unlock_bh(&x25_forward_list_lock);
  }