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/* Copyright (C) 2011-2016 B.A.T.M.A.N. contributors:
*
* Linus Lüssing, Marek Lindner
*
* 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 "bat_v_elp.h"
#include "main.h"
#include <linux/atomic.h>
#include <linux/byteorder/generic.h>
#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/fs.h>
#include <linux/if_ether.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/random.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
#include <linux/skbuff.h>
#include <linux/stddef.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/workqueue.h>
#include "bat_algo.h"
#include "hard-interface.h"
#include "packet.h"
#include "send.h"
/**
* batadv_v_elp_start_timer - restart timer for ELP periodic work
* @hard_iface: the interface for which the timer has to be reset
*/
static void batadv_v_elp_start_timer(struct batadv_hard_iface *hard_iface)
{
unsigned int msecs;
msecs = atomic_read(&hard_iface->bat_v.elp_interval) - BATADV_JITTER;
msecs += prandom_u32() % (2 * BATADV_JITTER);
queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.elp_wq,
msecs_to_jiffies(msecs));
}
/**
* batadv_v_elp_periodic_work - ELP periodic task per interface
* @work: work queue item
*
* Emits broadcast ELP message in regular intervals.
*/
static void batadv_v_elp_periodic_work(struct work_struct *work)
{
struct batadv_hard_iface *hard_iface;
struct batadv_hard_iface_bat_v *bat_v;
struct batadv_elp_packet *elp_packet;
struct batadv_priv *bat_priv;
struct sk_buff *skb;
u32 elp_interval;
bat_v = container_of(work, struct batadv_hard_iface_bat_v, elp_wq.work);
hard_iface = container_of(bat_v, struct batadv_hard_iface, bat_v);
bat_priv = netdev_priv(hard_iface->soft_iface);
if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
goto out;
/* we are in the process of shutting this interface down */
if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) ||
(hard_iface->if_status == BATADV_IF_TO_BE_REMOVED))
goto out;
/* the interface was enabled but may not be ready yet */
if (hard_iface->if_status != BATADV_IF_ACTIVE)
goto restart_timer;
skb = skb_copy(hard_iface->bat_v.elp_skb, GFP_ATOMIC);
if (!skb)
goto restart_timer;
elp_packet = (struct batadv_elp_packet *)skb->data;
elp_packet->seqno = htonl(atomic_read(&hard_iface->bat_v.elp_seqno));
elp_interval = atomic_read(&hard_iface->bat_v.elp_interval);
elp_packet->elp_interval = htonl(elp_interval);
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"Sending broadcast ELP packet on interface %s, seqno %u\n",
hard_iface->net_dev->name,
atomic_read(&hard_iface->bat_v.elp_seqno));
batadv_send_skb_packet(skb, hard_iface, batadv_broadcast_addr);
atomic_inc(&hard_iface->bat_v.elp_seqno);
restart_timer:
batadv_v_elp_start_timer(hard_iface);
out:
return;
}
/**
* batadv_v_elp_iface_enable - setup the ELP interface private resources
* @hard_iface: interface for which the data has to be prepared
*
* Return: 0 on success or a -ENOMEM in case of failure.
*/
int batadv_v_elp_iface_enable(struct batadv_hard_iface *hard_iface)
{
struct batadv_elp_packet *elp_packet;
unsigned char *elp_buff;
u32 random_seqno;
size_t size;
int res = -ENOMEM;
size = ETH_HLEN + NET_IP_ALIGN + BATADV_ELP_HLEN;
hard_iface->bat_v.elp_skb = dev_alloc_skb(size);
if (!hard_iface->bat_v.elp_skb)
goto out;
skb_reserve(hard_iface->bat_v.elp_skb, ETH_HLEN + NET_IP_ALIGN);
elp_buff = skb_push(hard_iface->bat_v.elp_skb, BATADV_ELP_HLEN);
elp_packet = (struct batadv_elp_packet *)elp_buff;
memset(elp_packet, 0, BATADV_ELP_HLEN);
elp_packet->packet_type = BATADV_ELP;
elp_packet->version = BATADV_COMPAT_VERSION;
/* randomize initial seqno to avoid collision */
get_random_bytes(&random_seqno, sizeof(random_seqno));
atomic_set(&hard_iface->bat_v.elp_seqno, random_seqno);
atomic_set(&hard_iface->bat_v.elp_interval, 500);
INIT_DELAYED_WORK(&hard_iface->bat_v.elp_wq,
batadv_v_elp_periodic_work);
batadv_v_elp_start_timer(hard_iface);
res = 0;
out:
return res;
}
/**
* batadv_v_elp_iface_disable - release ELP interface private resources
* @hard_iface: interface for which the resources have to be released
*/
void batadv_v_elp_iface_disable(struct batadv_hard_iface *hard_iface)
{
cancel_delayed_work_sync(&hard_iface->bat_v.elp_wq);
dev_kfree_skb(hard_iface->bat_v.elp_skb);
hard_iface->bat_v.elp_skb = NULL;
}
/**
* batadv_v_elp_primary_iface_set - change internal data to reflect the new
* primary interface
* @primary_iface: the new primary interface
*/
void batadv_v_elp_primary_iface_set(struct batadv_hard_iface *primary_iface)
{
struct batadv_hard_iface *hard_iface;
struct batadv_elp_packet *elp_packet;
struct sk_buff *skb;
/* update orig field of every elp iface belonging to this mesh */
rcu_read_lock();
list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
if (primary_iface->soft_iface != hard_iface->soft_iface)
continue;
if (!hard_iface->bat_v.elp_skb)
continue;
skb = hard_iface->bat_v.elp_skb;
elp_packet = (struct batadv_elp_packet *)skb->data;
ether_addr_copy(elp_packet->orig,
primary_iface->net_dev->dev_addr);
}
rcu_read_unlock();
}
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