/* Copyright (C) 2007-2017 B.A.T.M.A.N. contributors:
*
* Marek Lindner, Simon Wunderlich
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "routing.h"
#include "main.h"
#include <linux/atomic.h>
#include <linux/byteorder/generic.h>
#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/if_ether.h>
#include <linux/jiffies.h>
#include <linux/kref.h>
#include <linux/netdevice.h>
#include <linux/printk.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>
#include "bitarray.h"
#include "bridge_loop_avoidance.h"
#include "distributed-arp-table.h"
#include "fragmentation.h"
#include "hard-interface.h"
#include "icmp_socket.h"
#include "log.h"
#include "network-coding.h"
#include "originator.h"
#include "packet.h"
#include "send.h"
#include "soft-interface.h"
#include "tp_meter.h"
#include "translation-table.h"
#include "tvlv.h"
static int batadv_route_unicast_packet(struct sk_buff *skb,
struct batadv_hard_iface *recv_if);
/**
* _batadv_update_route - set the router for this originator
* @bat_priv: the bat priv with all the soft interface information
* @orig_node: orig node which is to be configured
* @recv_if: the receive interface for which this route is set
* @neigh_node: neighbor which should be the next router
*
* This function does not perform any error checks
*/
static void _batadv_update_route(struct batadv_priv *bat_priv,
struct batadv_orig_node *orig_node,
struct batadv_hard_iface *recv_if,
struct batadv_neigh_node *neigh_node)
{
struct batadv_orig_ifinfo *orig_ifinfo;
struct batadv_neigh_node *curr_router;
orig_ifinfo = batadv_orig_ifinfo_get(orig_node, recv_if);
if (!orig_ifinfo)
return;
spin_lock_bh(&orig_node->neigh_list_lock);
/* curr_router used earlier may not be the current orig_ifinfo->router
* anymore because it was dereferenced outside of the neigh_list_lock
* protected region. After the new best neighbor has replace the current
* best neighbor the reference counter needs to decrease. Consequently,
* the code needs to ensure the curr_router variable contains a pointer
* to the replaced best neighbor.
*/
curr_router = rcu_dereference_protected(orig_ifinfo->router, true);
/* increase refcount of new best neighbor */
if (neigh_node)
kref_get(&neigh_node->refcount);
rcu_assign_pointer(orig_ifinfo->router, neigh_node);
spin_unlock_bh(&orig_node->neigh_list_lock);
batadv_orig_ifinfo_put(orig_ifinfo);
/* route deleted */
if ((curr_router) && (!neigh_node)) {
batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
"Deleting route towards: %pM\n", orig_node->orig);
batadv_tt_global_del_orig(bat_priv, orig_node, -1,
"Deleted route towards originator");
/* route added */
} else if ((!curr_router) && (neigh_node)) {
batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
"Adding route towards: %pM (via %pM)\n",
orig_node->orig, neigh_node->addr);
/* route changed */
} else if (neigh_node && curr_router) {
batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
"Changing route towards: %pM (now via %pM - was via %pM)\n",
orig_node->orig, neigh_node->addr,
curr_router->addr