[mirror_ubuntu-zesty-kernel.git] / net / batman-adv / bat_v_elp.c

/* 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/ethtool.h>
#include <linux/fs.h>
#include <linux/if_ether.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/netdevice.h>
#include <linux/random.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>
#include <linux/stddef.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/workqueue.h>
#include <net/cfg80211.h>

#include "bat_algo.h"
#include "bat_v_ogm.h"
#include "hard-interface.h"
#include "log.h"
#include "originator.h"
#include "packet.h"
#include "routing.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_get_throughput - get the throughput towards a neighbour
 * @neigh: the neighbour for which the throughput has to be obtained
 *
 * Return: The throughput towards the given neighbour in multiples of 100kpbs
 *         (a value of '1' equals to 0.1Mbps, '10' equals 1Mbps, etc).
 */
static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh)
{
	struct batadv_hard_iface *hard_iface = neigh->if_incoming;
	struct ethtool_link_ksettings link_settings;
	struct net_device *real_netdev;
	struct station_info sinfo;
	u32 throughput;
	int ret;

	/* if the user specified a customised value for this interface, then
	 * return it directly
	 */
	throughput =  atomic_read(&hard_iface->bat_v.throughput_override);
	if (throughput != 0)
		return throughput;

	/* if this is a wireless device, then ask its throughput through
	 * cfg80211 API
	 */
	if (batadv_is_wifi_hardif(hard_iface)) {
		if (!batadv_is_cfg80211_hardif(hard_iface))
			/* unsupported WiFi driver version */
			goto default_throughput;

		real_netdev = batadv_get_real_netdev(hard_iface->net_dev);
		if (!real_netdev)
			goto default_throughput;

		ret = cfg80211_get_station(real_netdev, neigh->addr, &sinfo);

		dev_put(real_netdev);
		if (ret == -ENOENT) {
			/* Node is not associated anymore! It would be
			 * possible to delete this neighbor. For now set
			 * the throughput metric to 0.
			 */
			return 0;
		}
		if (!ret)
			return sinfo.expected_throughput / 100;
	}

	/* if not a wifi interface, check if this device provides data via
	 * ethtool (e.g. an Ethernet adapter)
	 */
	memset(&link_settings, 0, sizeof(link_settings));
	rtnl_lock();
	ret = __ethtool_get_link_ksettings(hard_iface->net_dev, &link_settings);
	rtnl_unlock();
	if (ret == 0) {
		/* link characteristics might change over time */
		if (link_settings.base.duplex == DUPLEX_FULL)
			hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX;
		else
			hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;

		throughput = link_settings.base.speed;
		if (throughput && (throughput != SPEED_UNKNOWN))
			return throughput * 10;
	}

default_throughput:
	if (!(hard_iface->bat_v.flags & BATADV_WARNING_DEFAULT)) {
		batadv_info(hard_iface->soft_iface,
			    "WiFi driver or ethtool info does not provide information about link speeds on interface %s, therefore defaulting to hardcoded throughput values of %u.%1u Mbps. Consider overriding the throughput manually or checking your driver.\n",
			    hard_iface->net_dev->name,
			    BATADV_THROUGHPUT_DEFAULT_VALUE / 10,
			    BATADV_THROUGHPUT_DEFAULT_VALUE % 10);
		hard_iface->bat_v.flags |= BATADV_WARNING_DEFAULT;
	}

	/* if none of the above cases apply, return the base_throughput */
	return BATADV_THROUGHPUT_DEFAULT_VALUE;
}

/**
 * batadv_v_elp_throughput_metric_update - worker updating the throughput metric
 *  of a single hop neighbour
 * @work: the work queue item
 */
void batadv_v_elp_throughput_metric_update(struct work_struct *work)
{
	struct batadv_hardif_neigh_node_bat_v *neigh_bat_v;
	struct batadv_hardif_neigh_node *neigh;

	neigh_bat_v = container_of(work, struct batadv_hardif_neigh_node_bat_v,
				   metric_work);
	neigh = container_of(neigh_bat_v, struct batadv_hardif_neigh_node,
			     bat_v);

	ewma_throughput_add(&neigh->bat_v.throughput,
			    batadv_v_elp_get_throughput(neigh));

	/* decrement refcounter to balance increment performed before scheduling
	 * this task
	 */
	batadv_hardif_neigh_put(neigh);
}

/**
 * batadv_v_elp_wifi_neigh_probe - send link probing packets to a neighbour
 * @neigh: the neighbour to probe
 *
 * Sends a predefined number of unicast wifi packets to a given neighbour in
 * order to trigger the throughput estimation on this link by the RC algorithm.
 * Packets are sent only if there there is not enough payload unicast traffic
 * towards this neighbour..
 *
 * Return: True on success and false in case of error during skb preparation.
 */
static bool
batadv_v_elp_wifi_neigh_probe(struct batadv_hardif_neigh_node *neigh)
{
	struct batadv_hard_iface *hard_iface = neigh->if_incoming;
	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
	unsigned long last_tx_diff;
	struct sk_buff *skb;
	int probe_len, i;
	int elp_skb_len;

	/* this probing routine is for Wifi neighbours only */
	if (!batadv_is_wifi_hardif(hard_iface))
		return true;

	/* probe the neighbor only if no unicast packets have been sent
	 * to it in the last 100 milliseconds: this is the rate control
	 * algorithm sampling interval (minstrel). In this way, if not
	 * enough traffic has been sent to the neighbor, batman-adv can
	 * generate 2 probe packets and push the RC algorithm to perform
	 * the sampling
	 */
	last_tx_diff = jiffies_to_msecs(jiffies - neigh->bat_v.last_unicast_tx);
	if (last_tx_diff <= BATADV_ELP_PROBE_MAX_TX_DIFF)
		return true;

	probe_len = max_t(int, sizeof(struct batadv_elp_packet),
			  BATADV_ELP_MIN_PROBE_SIZE);

	for (i = 0; i < BATADV_ELP_PROBES_PER_NODE; i++) {
		elp_skb_len = hard_iface->bat_v.elp_skb->len;
		skb = skb_copy_expand(hard_iface->bat_v.elp_skb, 0,
				      probe_len - elp_skb_len,
				      GFP_ATOMIC);
		if (!skb)
			return false;

		/* Tell the skb to get as big as the allocated space (we want
		 * the packet to be exactly of that size to make the link
		 * throughput estimation effective.
		 */
		skb_put(skb, probe_len - hard_iface->bat_v.elp_skb->len);

		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
			   "Sending unicast (probe) ELP packet on interface %s to %pM\n",
			   hard_iface->net_dev->name, neigh->addr);

		batadv_send_skb_packet(skb, hard_iface, neigh->addr);
	}

	return true;
}

/**
 * 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_hardif_neigh_node *hardif_neigh;
	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_broadcast_skb(skb, hard_iface);

	atomic_inc(&hard_iface->bat_v.elp_seqno);

	/* The throughput metric is updated on each sent packet. This way, if a
	 * node is dead and no longer sends packets, batman-adv is still able to
	 * react timely to its death.
	 *
	 * The throughput metric is updated by following these steps:
	 * 1) if the hard_iface is wifi => send a number of unicast ELPs for
	 *    probing/sampling to each neighbor
	 * 2) update the throughput metric value of each neighbor (note that the
	 *    value retrieved in this step might be 100ms old because the
	 *    probing packets at point 1) could still be in the HW queue)
	 */
	rcu_read_lock();
	hlist_for_each_entry_rcu(hardif_neigh, &hard_iface->neigh_list, list) {
		if (!batadv_v_elp_wifi_neigh_probe(hardif_neigh))
			/* if something goes wrong while probing, better to stop
			 * sending packets immediately and reschedule the task
			 */
			break;

		if (!kref_get_unless_zero(&hardif_neigh->refcount))
			continue;

		/* Reading the estimated throughput from cfg80211 is a task that
		 * may sleep and that is not allowed in an rcu protected
		 * context. Therefore schedule a task for that.
		 */
		queue_work(batadv_event_workqueue,
			   &hardif_neigh->bat_v.metric_work);
	}
	rcu_read_unlock();

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_put(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);

	/* assume full-duplex by default */
	hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX;

	/* warn the user (again) if there is no throughput data is available */
	hard_iface->bat_v.flags &= ~BATADV_WARNING_DEFAULT;

	if (batadv_is_wifi_hardif(hard_iface))
		hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;

	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_iface_activate - update the ELP buffer belonging to the given
 *  hard-interface
 * @primary_iface: the new primary interface
 * @hard_iface: interface holding the to-be-updated buffer
 */
void batadv_v_elp_iface_activate(struct batadv_hard_iface *primary_iface,
				 struct batadv_hard_iface *hard_iface)
{
	struct batadv_elp_packet *elp_packet;
	struct sk_buff *skb;

	if (!hard_iface->bat_v.elp_skb)
		return;

	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);
}

/**
 * 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;

	/* 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;

		batadv_v_elp_iface_activate(primary_iface, hard_iface);
	}
	rcu_read_unlock();
}

/**
 * batadv_v_elp_neigh_update - update an ELP neighbour node
 * @bat_priv: the bat priv with all the soft interface information
 * @neigh_addr: the neighbour interface address
 * @if_incoming: the interface the packet was received through
 * @elp_packet: the received ELP packet
 *
 * Updates the ELP neighbour node state with the data received within the new
 * ELP packet.
 */
static void batadv_v_elp_neigh_update(struct batadv_priv *bat_priv,
				      u8 *neigh_addr,
				      struct batadv_hard_iface *if_incoming,
				      struct batadv_elp_packet *elp_packet)

{
	struct batadv_neigh_node *neigh;
	struct batadv_orig_node *orig_neigh;
	struct batadv_hardif_neigh_node *hardif_neigh;
	s32 seqno_diff;
	s32 elp_latest_seqno;

	orig_neigh = batadv_v_ogm_orig_get(bat_priv, elp_packet->orig);
	if (!orig_neigh)
		return;

	neigh = batadv_neigh_node_get_or_create(orig_neigh,
						if_incoming, neigh_addr);
	if (!neigh)
		goto orig_free;

	hardif_neigh = batadv_hardif_neigh_get(if_incoming, neigh_addr);
	if (!hardif_neigh)
		goto neigh_free;

	elp_latest_seqno = hardif_neigh->bat_v.elp_latest_seqno;
	seqno_diff = ntohl(elp_packet->seqno) - elp_latest_seqno;

	/* known or older sequence numbers are ignored. However always adopt
	 * if the router seems to have been restarted.
	 */
	if (seqno_diff < 1 && seqno_diff > -BATADV_ELP_MAX_AGE)
		goto hardif_free;

	neigh->last_seen = jiffies;
	hardif_neigh->last_seen = jiffies;
	hardif_neigh->bat_v.elp_latest_seqno = ntohl(elp_packet->seqno);
	hardif_neigh->bat_v.elp_interval = ntohl(elp_packet->elp_interval);

hardif_free:
	if (hardif_neigh)
		batadv_hardif_neigh_put(hardif_neigh);
neigh_free:
	if (neigh)
		batadv_neigh_node_put(neigh);
orig_free:
	if (orig_neigh)
		batadv_orig_node_put(orig_neigh);
}

/**
 * batadv_v_elp_packet_recv - main ELP packet handler
 * @skb: the received packet
 * @if_incoming: the interface this packet was received through
 *
 * Return: NET_RX_SUCCESS and consumes the skb if the packet was peoperly
 * processed or NET_RX_DROP in case of failure.
 */
int batadv_v_elp_packet_recv(struct sk_buff *skb,
			     struct batadv_hard_iface *if_incoming)
{
	struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
	struct batadv_elp_packet *elp_packet;
	struct batadv_hard_iface *primary_if;
	struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
	bool res;
	int ret = NET_RX_DROP;

	res = batadv_check_management_packet(skb, if_incoming, BATADV_ELP_HLEN);
	if (!res)
		goto free_skb;

	if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
		goto free_skb;

	/* did we receive a B.A.T.M.A.N. V ELP packet on an interface
	 * that does not have B.A.T.M.A.N. V ELP enabled ?
	 */
	if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
		goto free_skb;

	elp_packet = (struct batadv_elp_packet *)skb->data;

	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
		   "Received ELP packet from %pM seqno %u ORIG: %pM\n",
		   ethhdr->h_source, ntohl(elp_packet->seqno),
		   elp_packet->orig);

	primary_if = batadv_primary_if_get_selected(bat_priv);
	if (!primary_if)
		goto free_skb;

	batadv_v_elp_neigh_update(bat_priv, ethhdr->h_source, if_incoming,
				  elp_packet);

	ret = NET_RX_SUCCESS;
	batadv_hardif_put(primary_if);

free_skb:
	if (ret == NET_RX_SUCCESS)
		consume_skb(skb);
	else
		kfree_skb(skb);

	return ret;
}
Commit	Line	Data
d6f94d91 LL	1	/* Copyright (C) 2011-2016 B.A.T.M.A.N. contributors:
	2	*
	3	* Linus Lüssing, Marek Lindner
	4	*
	5	* This program is free software; you can redistribute it and/or
	6	* modify it under the terms of version 2 of the GNU General Public
	7	* License as published by the Free Software Foundation.
	8	*
	9	* This program is distributed in the hope that it will be useful, but
	10	* WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	12	* General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, see <http://www.gnu.org/licenses/>.
	16	*/
	17
	18	#include "bat_v_elp.h"
	19	#include "main.h"
	20
	21	#include <linux/atomic.h>
	22	#include <linux/byteorder/generic.h>
	23	#include <linux/errno.h>
	24	#include <linux/etherdevice.h>
c833484e	25	#include <linux/ethtool.h>
d6f94d91 LL	26	#include <linux/fs.h>
	27	#include <linux/if_ether.h>
	28	#include <linux/jiffies.h>
	29	#include <linux/kernel.h>
c833484e	30	#include <linux/kref.h>
d6f94d91 LL	31	#include <linux/netdevice.h>
	32	#include <linux/random.h>
	33	#include <linux/rculist.h>
	34	#include <linux/rcupdate.h>
c833484e	35	#include <linux/rtnetlink.h>
d6f94d91 LL	36	#include <linux/skbuff.h>
	37	#include <linux/stddef.h>
	38	#include <linux/string.h>
	39	#include <linux/types.h>
	40	#include <linux/workqueue.h>
c833484e	41	#include <net/cfg80211.h>
d6f94d91 LL	42
d6f94d91 LL	43	#include "bat_algo.h"
9323158e	44	#include "bat_v_ogm.h"
d6f94d91	45	#include "hard-interface.h"
ba412080	46	#include "log.h"
162bd64c	47	#include "originator.h"
d6f94d91	48	#include "packet.h"
162bd64c	49	#include "routing.h"
d6f94d91 LL	50	#include "send.h"
	51
	52	/**
	53	* batadv_v_elp_start_timer - restart timer for ELP periodic work
	54	* @hard_iface: the interface for which the timer has to be reset
	55	*/
	56	static void batadv_v_elp_start_timer(struct batadv_hard_iface *hard_iface)
	57	{
	58	unsigned int msecs;
	59
	60	msecs = atomic_read(&hard_iface->bat_v.elp_interval) - BATADV_JITTER;
	61	msecs += prandom_u32() % (2 * BATADV_JITTER);
	62
	63	queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.elp_wq,
	64	msecs_to_jiffies(msecs));
	65	}
	66
c833484e AQ	67	/**
	68	* batadv_v_elp_get_throughput - get the throughput towards a neighbour
	69	* @neigh: the neighbour for which the throughput has to be obtained
	70	*
	71	* Return: The throughput towards the given neighbour in multiples of 100kpbs
	72	* (a value of '1' equals to 0.1Mbps, '10' equals 1Mbps, etc).
	73	*/
	74	static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh)
	75	{
	76	struct batadv_hard_iface *hard_iface = neigh->if_incoming;
	77	struct ethtool_link_ksettings link_settings;
1942de1b	78	struct net_device *real_netdev;
c833484e AQ	79	struct station_info sinfo;
	80	u32 throughput;
	81	int ret;
	82
	83	/* if the user specified a customised value for this interface, then
	84	* return it directly
	85	*/
	86	throughput = atomic_read(&hard_iface->bat_v.throughput_override);
	87	if (throughput != 0)
	88	return throughput;
	89
	90	/* if this is a wireless device, then ask its throughput through
	91	* cfg80211 API
	92	*/
10b1bbb4 SE	93	if (batadv_is_wifi_hardif(hard_iface)) {
10b1bbb4 SE	94	if (!batadv_is_cfg80211_hardif(hard_iface))
f44a3ae9 ML	95	/* unsupported WiFi driver version */
f44a3ae9 ML	96	goto default_throughput;
c833484e	97
1942de1b ML	98	real_netdev = batadv_get_real_netdev(hard_iface->net_dev);
	99	if (!real_netdev)
	100	goto default_throughput;
	101
	102	ret = cfg80211_get_station(real_netdev, neigh->addr, &sinfo);
	103
	104	dev_put(real_netdev);
f44a3ae9 ML	105	if (ret == -ENOENT) {
	106	/* Node is not associated anymore! It would be
	107	* possible to delete this neighbor. For now set
	108	* the throughput metric to 0.
	109	*/
	110	return 0;
	111	}
	112	if (!ret)
	113	return sinfo.expected_throughput / 100;
c833484e AQ	114	}
	115
	116	/* if not a wifi interface, check if this device provides data via
	117	* ethtool (e.g. an Ethernet adapter)
	118	*/
	119	memset(&link_settings, 0, sizeof(link_settings));
	120	rtnl_lock();
	121	ret = __ethtool_get_link_ksettings(hard_iface->net_dev, &link_settings);
	122	rtnl_unlock();
	123	if (ret == 0) {
	124	/* link characteristics might change over time */
	125	if (link_settings.base.duplex == DUPLEX_FULL)
	126	hard_iface->bat_v.flags \|= BATADV_FULL_DUPLEX;
	127	else
	128	hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;
	129
	130	throughput = link_settings.base.speed;
	131	if (throughput && (throughput != SPEED_UNKNOWN))
	132	return throughput * 10;
	133	}
	134
	135	default_throughput:
	136	if (!(hard_iface->bat_v.flags & BATADV_WARNING_DEFAULT)) {
	137	batadv_info(hard_iface->soft_iface,
	138	"WiFi driver or ethtool info does not provide information about link speeds on interface %s, therefore defaulting to hardcoded throughput values of %u.%1u Mbps. Consider overriding the throughput manually or checking your driver.\n",
	139	hard_iface->net_dev->name,
	140	BATADV_THROUGHPUT_DEFAULT_VALUE / 10,
	141	BATADV_THROUGHPUT_DEFAULT_VALUE % 10);
	142	hard_iface->bat_v.flags \|= BATADV_WARNING_DEFAULT;
	143	}
	144
	145	/* if none of the above cases apply, return the base_throughput */
	146	return BATADV_THROUGHPUT_DEFAULT_VALUE;
	147	}
	148
	149	/**
	150	* batadv_v_elp_throughput_metric_update - worker updating the throughput metric
	151	* of a single hop neighbour
	152	* @work: the work queue item
	153	*/
	154	void batadv_v_elp_throughput_metric_update(struct work_struct *work)
	155	{
	156	struct batadv_hardif_neigh_node_bat_v *neigh_bat_v;
	157	struct batadv_hardif_neigh_node *neigh;
	158
	159	neigh_bat_v = container_of(work, struct batadv_hardif_neigh_node_bat_v,
	160	metric_work);
	161	neigh = container_of(neigh_bat_v, struct batadv_hardif_neigh_node,
	162	bat_v);
	163
	164	ewma_throughput_add(&neigh->bat_v.throughput,
	165	batadv_v_elp_get_throughput(neigh));
	166
	167	/* decrement refcounter to balance increment performed before scheduling
	168	* this task
	169	*/
	170	batadv_hardif_neigh_put(neigh);
	171	}
	172
8d2d499e AQ	173	/**
	174	* batadv_v_elp_wifi_neigh_probe - send link probing packets to a neighbour
	175	* @neigh: the neighbour to probe
	176	*
	177	* Sends a predefined number of unicast wifi packets to a given neighbour in
	178	* order to trigger the throughput estimation on this link by the RC algorithm.
	179	* Packets are sent only if there there is not enough payload unicast traffic
	180	* towards this neighbour..
	181	*
	182	* Return: True on success and false in case of error during skb preparation.
	183	*/
	184	static bool
	185	batadv_v_elp_wifi_neigh_probe(struct batadv_hardif_neigh_node *neigh)
	186	{
	187	struct batadv_hard_iface *hard_iface = neigh->if_incoming;
	188	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
	189	unsigned long last_tx_diff;
	190	struct sk_buff *skb;
	191	int probe_len, i;
	192	int elp_skb_len;
	193
	194	/* this probing routine is for Wifi neighbours only */
10b1bbb4	195	if (!batadv_is_wifi_hardif(hard_iface))
8d2d499e AQ	196	return true;
	197
	198	/* probe the neighbor only if no unicast packets have been sent
	199	* to it in the last 100 milliseconds: this is the rate control
	200	* algorithm sampling interval (minstrel). In this way, if not
	201	* enough traffic has been sent to the neighbor, batman-adv can
	202	* generate 2 probe packets and push the RC algorithm to perform
	203	* the sampling
	204	*/
	205	last_tx_diff = jiffies_to_msecs(jiffies - neigh->bat_v.last_unicast_tx);
	206	if (last_tx_diff <= BATADV_ELP_PROBE_MAX_TX_DIFF)
	207	return true;
	208
	209	probe_len = max_t(int, sizeof(struct batadv_elp_packet),
	210	BATADV_ELP_MIN_PROBE_SIZE);
	211
	212	for (i = 0; i < BATADV_ELP_PROBES_PER_NODE; i++) {
	213	elp_skb_len = hard_iface->bat_v.elp_skb->len;
	214	skb = skb_copy_expand(hard_iface->bat_v.elp_skb, 0,
	215	probe_len - elp_skb_len,
	216	GFP_ATOMIC);
	217	if (!skb)
	218	return false;
	219
	220	/* Tell the skb to get as big as the allocated space (we want
	221	* the packet to be exactly of that size to make the link
	222	* throughput estimation effective.
	223	*/
	224	skb_put(skb, probe_len - hard_iface->bat_v.elp_skb->len);
	225
	226	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
	227	"Sending unicast (probe) ELP packet on interface %s to %pM\n",
	228	hard_iface->net_dev->name, neigh->addr);
	229
	230	batadv_send_skb_packet(skb, hard_iface, neigh->addr);
	231	}
	232
	233	return true;
	234	}
	235
d6f94d91 LL	236	/**
	237	* batadv_v_elp_periodic_work - ELP periodic task per interface
	238	* @work: work queue item
	239	*
	240	* Emits broadcast ELP message in regular intervals.
	241	*/
	242	static void batadv_v_elp_periodic_work(struct work_struct *work)
	243	{
c833484e	244	struct batadv_hardif_neigh_node *hardif_neigh;
d6f94d91 LL	245	struct batadv_hard_iface *hard_iface;
	246	struct batadv_hard_iface_bat_v *bat_v;
	247	struct batadv_elp_packet *elp_packet;
	248	struct batadv_priv *bat_priv;
	249	struct sk_buff *skb;
	250	u32 elp_interval;
	251
	252	bat_v = container_of(work, struct batadv_hard_iface_bat_v, elp_wq.work);
	253	hard_iface = container_of(bat_v, struct batadv_hard_iface, bat_v);
	254	bat_priv = netdev_priv(hard_iface->soft_iface);
	255
	256	if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
	257	goto out;
	258
	259	/* we are in the process of shutting this interface down */
	260	if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) \|\|
	261	(hard_iface->if_status == BATADV_IF_TO_BE_REMOVED))
	262	goto out;
	263
	264	/* the interface was enabled but may not be ready yet */
	265	if (hard_iface->if_status != BATADV_IF_ACTIVE)
	266	goto restart_timer;
	267
	268	skb = skb_copy(hard_iface->bat_v.elp_skb, GFP_ATOMIC);
	269	if (!skb)
	270	goto restart_timer;
	271
	272	elp_packet = (struct batadv_elp_packet *)skb->data;
	273	elp_packet->seqno = htonl(atomic_read(&hard_iface->bat_v.elp_seqno));
	274	elp_interval = atomic_read(&hard_iface->bat_v.elp_interval);
	275	elp_packet->elp_interval = htonl(elp_interval);
	276
	277	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
	278	"Sending broadcast ELP packet on interface %s, seqno %u\n",
	279	hard_iface->net_dev->name,
	280	atomic_read(&hard_iface->bat_v.elp_seqno));
	281
95d39278	282	batadv_send_broadcast_skb(skb, hard_iface);
d6f94d91 LL	283
	284	atomic_inc(&hard_iface->bat_v.elp_seqno);
	285
c833484e AQ	286	/* The throughput metric is updated on each sent packet. This way, if a
	287	* node is dead and no longer sends packets, batman-adv is still able to
	288	* react timely to its death.
	289	*
	290	* The throughput metric is updated by following these steps:
	291	* 1) if the hard_iface is wifi => send a number of unicast ELPs for
	292	* probing/sampling to each neighbor
	293	* 2) update the throughput metric value of each neighbor (note that the
	294	* value retrieved in this step might be 100ms old because the
	295	* probing packets at point 1) could still be in the HW queue)
	296	*/
	297	rcu_read_lock();
	298	hlist_for_each_entry_rcu(hardif_neigh, &hard_iface->neigh_list, list) {
8d2d499e AQ	299	if (!batadv_v_elp_wifi_neigh_probe(hardif_neigh))
	300	/* if something goes wrong while probing, better to stop
	301	* sending packets immediately and reschedule the task
	302	*/
	303	break;
	304
c833484e AQ	305	if (!kref_get_unless_zero(&hardif_neigh->refcount))
	306	continue;
	307
	308	/* Reading the estimated throughput from cfg80211 is a task that
	309	* may sleep and that is not allowed in an rcu protected
	310	* context. Therefore schedule a task for that.
	311	*/
	312	queue_work(batadv_event_workqueue,
	313	&hardif_neigh->bat_v.metric_work);
	314	}
	315	rcu_read_unlock();
	316
d6f94d91 LL	317	restart_timer:
	318	batadv_v_elp_start_timer(hard_iface);
	319	out:
	320	return;
	321	}
	322
	323	/**
	324	* batadv_v_elp_iface_enable - setup the ELP interface private resources
	325	* @hard_iface: interface for which the data has to be prepared
	326	*
	327	* Return: 0 on success or a -ENOMEM in case of failure.
	328	*/
	329	int batadv_v_elp_iface_enable(struct batadv_hard_iface *hard_iface)
	330	{
	331	struct batadv_elp_packet *elp_packet;
	332	unsigned char *elp_buff;
	333	u32 random_seqno;
	334	size_t size;
	335	int res = -ENOMEM;
	336
	337	size = ETH_HLEN + NET_IP_ALIGN + BATADV_ELP_HLEN;
	338	hard_iface->bat_v.elp_skb = dev_alloc_skb(size);
	339	if (!hard_iface->bat_v.elp_skb)
	340	goto out;
	341
	342	skb_reserve(hard_iface->bat_v.elp_skb, ETH_HLEN + NET_IP_ALIGN);
1e5d343b	343	elp_buff = skb_put(hard_iface->bat_v.elp_skb, BATADV_ELP_HLEN);
d6f94d91 LL	344	elp_packet = (struct batadv_elp_packet *)elp_buff;
	345	memset(elp_packet, 0, BATADV_ELP_HLEN);
	346
	347	elp_packet->packet_type = BATADV_ELP;
	348	elp_packet->version = BATADV_COMPAT_VERSION;
	349
	350	/* randomize initial seqno to avoid collision */
	351	get_random_bytes(&random_seqno, sizeof(random_seqno));
	352	atomic_set(&hard_iface->bat_v.elp_seqno, random_seqno);
d6f94d91	353
c833484e AQ	354	/* assume full-duplex by default */
	355	hard_iface->bat_v.flags \|= BATADV_FULL_DUPLEX;
	356
	357	/* warn the user (again) if there is no throughput data is available */
	358	hard_iface->bat_v.flags &= ~BATADV_WARNING_DEFAULT;
	359
10b1bbb4	360	if (batadv_is_wifi_hardif(hard_iface))
c833484e AQ	361	hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;
c833484e AQ	362
d6f94d91 LL	363	INIT_DELAYED_WORK(&hard_iface->bat_v.elp_wq,
	364	batadv_v_elp_periodic_work);
	365	batadv_v_elp_start_timer(hard_iface);
	366	res = 0;
	367
	368	out:
	369	return res;
	370	}
	371
	372	/**
	373	* batadv_v_elp_iface_disable - release ELP interface private resources
	374	* @hard_iface: interface for which the resources have to be released
	375	*/
	376	void batadv_v_elp_iface_disable(struct batadv_hard_iface *hard_iface)
	377	{
	378	cancel_delayed_work_sync(&hard_iface->bat_v.elp_wq);
	379
	380	dev_kfree_skb(hard_iface->bat_v.elp_skb);
	381	hard_iface->bat_v.elp_skb = NULL;
	382	}
	383
ebe24cea ML	384	/**
	385	* batadv_v_elp_iface_activate - update the ELP buffer belonging to the given
	386	* hard-interface
	387	* @primary_iface: the new primary interface
	388	* @hard_iface: interface holding the to-be-updated buffer
	389	*/
	390	void batadv_v_elp_iface_activate(struct batadv_hard_iface *primary_iface,
	391	struct batadv_hard_iface *hard_iface)
	392	{
	393	struct batadv_elp_packet *elp_packet;
	394	struct sk_buff *skb;
	395
	396	if (!hard_iface->bat_v.elp_skb)
	397	return;
	398
	399	skb = hard_iface->bat_v.elp_skb;
	400	elp_packet = (struct batadv_elp_packet *)skb->data;
	401	ether_addr_copy(elp_packet->orig,
	402	primary_iface->net_dev->dev_addr);
	403	}
	404
d6f94d91 LL	405	/**
	406	* batadv_v_elp_primary_iface_set - change internal data to reflect the new
	407	* primary interface
	408	* @primary_iface: the new primary interface
	409	*/
	410	void batadv_v_elp_primary_iface_set(struct batadv_hard_iface *primary_iface)
	411	{
	412	struct batadv_hard_iface *hard_iface;
d6f94d91 LL	413
	414	/* update orig field of every elp iface belonging to this mesh */
	415	rcu_read_lock();
	416	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
	417	if (primary_iface->soft_iface != hard_iface->soft_iface)
	418	continue;
	419
ebe24cea	420	batadv_v_elp_iface_activate(primary_iface, hard_iface);
d6f94d91 LL	421	}
	422	rcu_read_unlock();
	423	}
162bd64c	424
162bd64c LL	425	/**
	426	* batadv_v_elp_neigh_update - update an ELP neighbour node
	427	* @bat_priv: the bat priv with all the soft interface information
	428	* @neigh_addr: the neighbour interface address
	429	* @if_incoming: the interface the packet was received through
	430	* @elp_packet: the received ELP packet
	431	*
	432	* Updates the ELP neighbour node state with the data received within the new
	433	* ELP packet.
	434	*/
	435	static void batadv_v_elp_neigh_update(struct batadv_priv *bat_priv,
	436	u8 *neigh_addr,
	437	struct batadv_hard_iface *if_incoming,
	438	struct batadv_elp_packet *elp_packet)
	439
	440	{
	441	struct batadv_neigh_node *neigh;
	442	struct batadv_orig_node *orig_neigh;
	443	struct batadv_hardif_neigh_node *hardif_neigh;
	444	s32 seqno_diff;
	445	s32 elp_latest_seqno;
	446
	447	orig_neigh = batadv_v_ogm_orig_get(bat_priv, elp_packet->orig);
	448	if (!orig_neigh)
	449	return;
	450
6f0a6b5e ML	451	neigh = batadv_neigh_node_get_or_create(orig_neigh,
6f0a6b5e ML	452	if_incoming, neigh_addr);
162bd64c LL	453	if (!neigh)
	454	goto orig_free;
	455
	456	hardif_neigh = batadv_hardif_neigh_get(if_incoming, neigh_addr);
	457	if (!hardif_neigh)
	458	goto neigh_free;
	459
	460	elp_latest_seqno = hardif_neigh->bat_v.elp_latest_seqno;
	461	seqno_diff = ntohl(elp_packet->seqno) - elp_latest_seqno;
	462
	463	/* known or older sequence numbers are ignored. However always adopt
	464	* if the router seems to have been restarted.
	465	*/
	466	if (seqno_diff < 1 && seqno_diff > -BATADV_ELP_MAX_AGE)
	467	goto hardif_free;
	468
	469	neigh->last_seen = jiffies;
	470	hardif_neigh->last_seen = jiffies;
	471	hardif_neigh->bat_v.elp_latest_seqno = ntohl(elp_packet->seqno);
	472	hardif_neigh->bat_v.elp_interval = ntohl(elp_packet->elp_interval);
	473
	474	hardif_free:
	475	if (hardif_neigh)
	476	batadv_hardif_neigh_put(hardif_neigh);
	477	neigh_free:
	478	if (neigh)
	479	batadv_neigh_node_put(neigh);
	480	orig_free:
	481	if (orig_neigh)
	482	batadv_orig_node_put(orig_neigh);
	483	}
	484
	485	/**
	486	* batadv_v_elp_packet_recv - main ELP packet handler
	487	* @skb: the received packet
	488	* @if_incoming: the interface this packet was received through
	489	*
	490	* Return: NET_RX_SUCCESS and consumes the skb if the packet was peoperly
	491	* processed or NET_RX_DROP in case of failure.
	492	*/
	493	int batadv_v_elp_packet_recv(struct sk_buff *skb,
	494	struct batadv_hard_iface *if_incoming)
	495	{
	496	struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
	497	struct batadv_elp_packet *elp_packet;
	498	struct batadv_hard_iface *primary_if;
	499	struct ethhdr ethhdr = (struct ethhdr )skb_mac_header(skb);
b91a2543 SE	500	bool res;
b91a2543 SE	501	int ret = NET_RX_DROP;
162bd64c	502
b91a2543 SE	503	res = batadv_check_management_packet(skb, if_incoming, BATADV_ELP_HLEN);
	504	if (!res)
	505	goto free_skb;
162bd64c LL	506
162bd64c LL	507	if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
b91a2543	508	goto free_skb;
162bd64c LL	509
	510	/* did we receive a B.A.T.M.A.N. V ELP packet on an interface
	511	* that does not have B.A.T.M.A.N. V ELP enabled ?
	512	*/
29824a55	513	if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
b91a2543	514	goto free_skb;
162bd64c LL	515
	516	elp_packet = (struct batadv_elp_packet *)skb->data;
	517
	518	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
	519	"Received ELP packet from %pM seqno %u ORIG: %pM\n",
	520	ethhdr->h_source, ntohl(elp_packet->seqno),
	521	elp_packet->orig);
	522
	523	primary_if = batadv_primary_if_get_selected(bat_priv);
	524	if (!primary_if)
b91a2543	525	goto free_skb;
162bd64c LL	526
	527	batadv_v_elp_neigh_update(bat_priv, ethhdr->h_source, if_incoming,
	528	elp_packet);
	529
b91a2543 SE	530	ret = NET_RX_SUCCESS;
	531	batadv_hardif_put(primary_if);
	532
	533	free_skb:
	534	if (ret == NET_RX_SUCCESS)
	535	consume_skb(skb);
	536	else
	537	kfree_skb(skb);
	538
	539	return ret;
162bd64c	540	}