path: root/net/batman-adv/routing.c

/* Copyright (C) 2007-2014 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 "main.h"
#include "routing.h"
#include "send.h"
#include "soft-interface.h"
#include "hard-interface.h"
#include "icmp_socket.h"
#include "translation-table.h"
#include "originator.h"
#include "bridge_loop_avoidance.h"
#include "distributed-arp-table.h"
#include "network-coding.h"
#include "fragmentation.h"

#include <linux/if_vlan.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;

	rcu_read_lock();
	curr_router = rcu_dereference(orig_ifinfo->router);
	if (curr_router && !atomic_inc_not_zero(&curr_router->refcount))
		curr_router = NULL;
	rcu_read_unlock();

	/* 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);
	}

	if (curr_router)
		batadv_neigh_node_free_ref(curr_router);

	/* increase refcount of new best neighbor */
	if (neigh_node && !atomic_inc_not_zero(&neigh_node->refcount))
		neigh_node = NULL;

	spin_lock_bh(&orig_node->neigh_list_lock);
	rcu_assign_pointer(orig_ifinfo->router, neigh_node);
	spin_unlock_bh(&orig_node->neigh_list_lock);
	batadv_orig_ifinfo_free_ref(orig_ifinfo);

	/* decrease refcount of previous best neighbor */
	if (curr_router)
		batadv_neigh_node_free_ref(curr_router);
}

/**
 * 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
 */
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_neigh_node *router = NULL;

	if (!orig_node)
		goto out;

	router = batadv_orig_router_get(orig_node, recv_if);

	if (router != neigh_node)
		_batadv_update_route(bat_priv, orig_node, recv_if, neigh_node);

out:
	if (router)
		batadv_neigh_node_free_ref(router);
}

/* checks whether the host restarted and is in the protection time.
 * returns:
 *  0 if the packet is to be accepted
 *  1 if the packet is to be ignored.
 */
int batadv_window_protected(struct batadv_priv *bat_priv, int32_t seq_num_diff,
			    unsigned long *last_reset)
{
	if (seq_num_diff <= -BATADV_TQ_LOCAL_WINDOW_SIZE ||
	    seq_num_diff >= BATADV_EXPECTED_SEQNO_RANGE) {
		if (!batadv_has_timed_out(*last_reset,
					  BATADV_RESET_PROTECTION_MS))
			return 1;

		*last_reset = jiffies;
		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
			   "old packet received, start protection\n");
	}

	return 0;
}

bool batadv_check_management_packet(struct sk_buff *skb,
				    struct batadv_hard_iface