linux-imx

// SPDX-License-Identifier: GPL-2.0

/* Copyright (C) 2007-2019  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 <uapi/linux/batadv_packet.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 "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);