[linux-2.6-block.git] / net / batman-adv / bat_v_elp.c

// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2011-2019  B.A.T.M.A.N. contributors:
 *
 * Linus Lüssing, Marek Lindner
 */

#include "bat_v_elp.h"
#include "main.h"

#include <linux/atomic.h>
#include <linux/bitops.h>
#include <linux/byteorder/generic.h>
#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/gfp.h>
#include <linux/if_ether.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/netdevice.h>
#include <linux/nl80211.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 <uapi/linux/batadv_packet.h>

#include "bat_algo.h"
#include "bat_v_ogm.h"
#include "hard-interface.h"
#include "log.h"
#include "originator.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);

		if (!ret) {
			/* free the TID stats immediately */
			cfg80211_sinfo_release_content(&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)
			goto default_throughput;
		if (!(sinfo.filled & BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT)))
			goto default_throughput;

		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();

	/* Virtual interface drivers such as tun / tap interfaces, VLAN, etc
	 * tend to initialize the interface throughput with some value for the
	 * sake of having a throughput number to export via ethtool. This
	 * exported throughput leaves batman-adv to conclude the interface
	 * throughput is genuine (reflecting reality), thus no measurements
	 * are necessary.
	 *
	 * Based on the observation that those interface types also tend to set
	 * the link auto-negotiation to 'off', batman-adv shall check this
	 * setting to differentiate between genuine link throughput information
	 * and placeholders installed by virtual interfaces.
	 */
	if (ret == 0 && link_settings.base.autoneg == AUTONEG_ENABLE) {
		/* 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_zero(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;
	bool ret;

	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.
		 */
		ret = queue_work(batadv_event_workqueue,
				 &hardif_neigh->bat_v.metric_work);

		if (!ret)
			batadv_hardif_neigh_put(hardif_neigh);
	}
	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)
{
	static const size_t tvlv_padding = sizeof(__be32);
	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 + tvlv_padding;
	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_zero(hard_iface->bat_v.elp_skb,
				BATADV_ELP_HLEN + tvlv_padding);
	elp_packet = (struct batadv_elp_packet *)elp_buff;

	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
7db7d9f3	1	// SPDX-License-Identifier: GPL-2.0
7a79d717	2	/* Copyright (C) 2011-2019 B.A.T.M.A.N. contributors:
d6f94d91 LL	3	*
d6f94d91 LL	4	* Linus Lüssing, Marek Lindner
d6f94d91 LL	5	*/
	6
	7	#include "bat_v_elp.h"
	8	#include "main.h"
	9
	10	#include <linux/atomic.h>
d6289088	11	#include <linux/bitops.h>
d6f94d91 LL	12	#include <linux/byteorder/generic.h>
	13	#include <linux/errno.h>
	14	#include <linux/etherdevice.h>
c833484e	15	#include <linux/ethtool.h>
b92b94ac	16	#include <linux/gfp.h>
d6f94d91 LL	17	#include <linux/if_ether.h>
	18	#include <linux/jiffies.h>
	19	#include <linux/kernel.h>
c833484e	20	#include <linux/kref.h>
d6f94d91	21	#include <linux/netdevice.h>
d6289088	22	#include <linux/nl80211.h>
d6f94d91 LL	23	#include <linux/random.h>
	24	#include <linux/rculist.h>
	25	#include <linux/rcupdate.h>
c833484e	26	#include <linux/rtnetlink.h>
d6f94d91 LL	27	#include <linux/skbuff.h>
	28	#include <linux/stddef.h>
	29	#include <linux/string.h>
	30	#include <linux/types.h>
	31	#include <linux/workqueue.h>
c833484e	32	#include <net/cfg80211.h>
fec149f5	33	#include <uapi/linux/batadv_packet.h>
d6f94d91 LL	34
d6f94d91 LL	35	#include "bat_algo.h"
9323158e	36	#include "bat_v_ogm.h"
d6f94d91	37	#include "hard-interface.h"
ba412080	38	#include "log.h"
162bd64c	39	#include "originator.h"
162bd64c	40	#include "routing.h"
d6f94d91 LL	41	#include "send.h"
	42
	43	/**
7e9a8c2c	44	* batadv_v_elp_start_timer() - restart timer for ELP periodic work
d6f94d91 LL	45	* @hard_iface: the interface for which the timer has to be reset
	46	*/
	47	static void batadv_v_elp_start_timer(struct batadv_hard_iface *hard_iface)
	48	{
	49	unsigned int msecs;
	50
	51	msecs = atomic_read(&hard_iface->bat_v.elp_interval) - BATADV_JITTER;
	52	msecs += prandom_u32() % (2 * BATADV_JITTER);
	53
	54	queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.elp_wq,
	55	msecs_to_jiffies(msecs));
	56	}
	57
c833484e	58	/**
7e9a8c2c	59	* batadv_v_elp_get_throughput() - get the throughput towards a neighbour
c833484e AQ	60	* @neigh: the neighbour for which the throughput has to be obtained
	61	*
	62	* Return: The throughput towards the given neighbour in multiples of 100kpbs
	63	* (a value of '1' equals to 0.1Mbps, '10' equals 1Mbps, etc).
	64	*/
	65	static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh)
	66	{
	67	struct batadv_hard_iface *hard_iface = neigh->if_incoming;
	68	struct ethtool_link_ksettings link_settings;
1942de1b	69	struct net_device *real_netdev;
c833484e AQ	70	struct station_info sinfo;
	71	u32 throughput;
	72	int ret;
	73
	74	/* if the user specified a customised value for this interface, then
	75	* return it directly
	76	*/
	77	throughput = atomic_read(&hard_iface->bat_v.throughput_override);
	78	if (throughput != 0)
	79	return throughput;
	80
	81	/* if this is a wireless device, then ask its throughput through
	82	* cfg80211 API
	83	*/
10b1bbb4 SE	84	if (batadv_is_wifi_hardif(hard_iface)) {
10b1bbb4 SE	85	if (!batadv_is_cfg80211_hardif(hard_iface))
f44a3ae9 ML	86	/* unsupported WiFi driver version */
f44a3ae9 ML	87	goto default_throughput;
c833484e	88
1942de1b ML	89	real_netdev = batadv_get_real_netdev(hard_iface->net_dev);
	90	if (!real_netdev)
	91	goto default_throughput;
	92
	93	ret = cfg80211_get_station(real_netdev, neigh->addr, &sinfo);
	94
ca8c3b92 AR	95	if (!ret) {
	96	/* free the TID stats immediately */
	97	cfg80211_sinfo_release_content(&sinfo);
	98	}
7d652669	99
1942de1b	100	dev_put(real_netdev);
f44a3ae9 ML	101	if (ret == -ENOENT) {
	102	/* Node is not associated anymore! It would be
	103	* possible to delete this neighbor. For now set
	104	* the throughput metric to 0.
	105	*/
	106	return 0;
	107	}
3f3f8732 SE	108	if (ret)
3f3f8732 SE	109	goto default_throughput;
d6289088 SE	110	if (!(sinfo.filled & BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT)))
d6289088 SE	111	goto default_throughput;
3f3f8732 SE	112
3f3f8732 SE	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();
8c46fcd7 ML	123
	124	/* Virtual interface drivers such as tun / tap interfaces, VLAN, etc
	125	* tend to initialize the interface throughput with some value for the
	126	* sake of having a throughput number to export via ethtool. This
	127	* exported throughput leaves batman-adv to conclude the interface
	128	* throughput is genuine (reflecting reality), thus no measurements
	129	* are necessary.
	130	*
	131	* Based on the observation that those interface types also tend to set
	132	* the link auto-negotiation to 'off', batman-adv shall check this
	133	* setting to differentiate between genuine link throughput information
	134	* and placeholders installed by virtual interfaces.
	135	*/
	136	if (ret == 0 && link_settings.base.autoneg == AUTONEG_ENABLE) {
c833484e AQ	137	/* link characteristics might change over time */
	138	if (link_settings.base.duplex == DUPLEX_FULL)
	139	hard_iface->bat_v.flags \|= BATADV_FULL_DUPLEX;
	140	else
	141	hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;
	142
	143	throughput = link_settings.base.speed;
825ffe1f	144	if (throughput && throughput != SPEED_UNKNOWN)
c833484e AQ	145	return throughput * 10;
	146	}
	147
	148	default_throughput:
	149	if (!(hard_iface->bat_v.flags & BATADV_WARNING_DEFAULT)) {
	150	batadv_info(hard_iface->soft_iface,
	151	"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",
	152	hard_iface->net_dev->name,
	153	BATADV_THROUGHPUT_DEFAULT_VALUE / 10,
	154	BATADV_THROUGHPUT_DEFAULT_VALUE % 10);
	155	hard_iface->bat_v.flags \|= BATADV_WARNING_DEFAULT;
	156	}
	157
	158	/* if none of the above cases apply, return the base_throughput */
	159	return BATADV_THROUGHPUT_DEFAULT_VALUE;
	160	}
	161
	162	/**
7e9a8c2c SE	163	* batadv_v_elp_throughput_metric_update() - worker updating the throughput
7e9a8c2c SE	164	* metric of a single hop neighbour
c833484e AQ	165	* @work: the work queue item
	166	*/
	167	void batadv_v_elp_throughput_metric_update(struct work_struct *work)
	168	{
	169	struct batadv_hardif_neigh_node_bat_v *neigh_bat_v;
	170	struct batadv_hardif_neigh_node *neigh;
	171
	172	neigh_bat_v = container_of(work, struct batadv_hardif_neigh_node_bat_v,
	173	metric_work);
	174	neigh = container_of(neigh_bat_v, struct batadv_hardif_neigh_node,
	175	bat_v);
	176
	177	ewma_throughput_add(&neigh->bat_v.throughput,
	178	batadv_v_elp_get_throughput(neigh));
	179
	180	/* decrement refcounter to balance increment performed before scheduling
	181	* this task
	182	*/
	183	batadv_hardif_neigh_put(neigh);
	184	}
	185
8d2d499e	186	/**
7e9a8c2c	187	* batadv_v_elp_wifi_neigh_probe() - send link probing packets to a neighbour
8d2d499e AQ	188	* @neigh: the neighbour to probe
	189	*
	190	* Sends a predefined number of unicast wifi packets to a given neighbour in
	191	* order to trigger the throughput estimation on this link by the RC algorithm.
	192	* Packets are sent only if there there is not enough payload unicast traffic
	193	* towards this neighbour..
	194	*
	195	* Return: True on success and false in case of error during skb preparation.
	196	*/
	197	static bool
	198	batadv_v_elp_wifi_neigh_probe(struct batadv_hardif_neigh_node *neigh)
	199	{
	200	struct batadv_hard_iface *hard_iface = neigh->if_incoming;
	201	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
	202	unsigned long last_tx_diff;
	203	struct sk_buff *skb;
	204	int probe_len, i;
	205	int elp_skb_len;
	206
	207	/* this probing routine is for Wifi neighbours only */
10b1bbb4	208	if (!batadv_is_wifi_hardif(hard_iface))
8d2d499e AQ	209	return true;
	210
	211	/* probe the neighbor only if no unicast packets have been sent
	212	* to it in the last 100 milliseconds: this is the rate control
	213	* algorithm sampling interval (minstrel). In this way, if not
	214	* enough traffic has been sent to the neighbor, batman-adv can
	215	* generate 2 probe packets and push the RC algorithm to perform
	216	* the sampling
	217	*/
	218	last_tx_diff = jiffies_to_msecs(jiffies - neigh->bat_v.last_unicast_tx);
	219	if (last_tx_diff <= BATADV_ELP_PROBE_MAX_TX_DIFF)
	220	return true;
	221
	222	probe_len = max_t(int, sizeof(struct batadv_elp_packet),
	223	BATADV_ELP_MIN_PROBE_SIZE);
	224
	225	for (i = 0; i < BATADV_ELP_PROBES_PER_NODE; i++) {
	226	elp_skb_len = hard_iface->bat_v.elp_skb->len;
	227	skb = skb_copy_expand(hard_iface->bat_v.elp_skb, 0,
	228	probe_len - elp_skb_len,
	229	GFP_ATOMIC);
	230	if (!skb)
	231	return false;
	232
	233	/* Tell the skb to get as big as the allocated space (we want
	234	* the packet to be exactly of that size to make the link
	235	* throughput estimation effective.
	236	*/
88d0895d	237	skb_put_zero(skb, probe_len - hard_iface->bat_v.elp_skb->len);
8d2d499e AQ	238
	239	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
	240	"Sending unicast (probe) ELP packet on interface %s to %pM\n",
	241	hard_iface->net_dev->name, neigh->addr);
	242
	243	batadv_send_skb_packet(skb, hard_iface, neigh->addr);
	244	}
	245
	246	return true;
	247	}
	248
d6f94d91	249	/**
7e9a8c2c	250	* batadv_v_elp_periodic_work() - ELP periodic task per interface
d6f94d91 LL	251	* @work: work queue item
	252	*
	253	* Emits broadcast ELP message in regular intervals.
	254	*/
	255	static void batadv_v_elp_periodic_work(struct work_struct *work)
	256	{
c833484e	257	struct batadv_hardif_neigh_node *hardif_neigh;
d6f94d91 LL	258	struct batadv_hard_iface *hard_iface;
	259	struct batadv_hard_iface_bat_v *bat_v;
	260	struct batadv_elp_packet *elp_packet;
	261	struct batadv_priv *bat_priv;
	262	struct sk_buff *skb;
	263	u32 elp_interval;
4c4af690	264	bool ret;
d6f94d91 LL	265
	266	bat_v = container_of(work, struct batadv_hard_iface_bat_v, elp_wq.work);
	267	hard_iface = container_of(bat_v, struct batadv_hard_iface, bat_v);
	268	bat_priv = netdev_priv(hard_iface->soft_iface);
	269
	270	if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
	271	goto out;
	272
	273	/* we are in the process of shutting this interface down */
825ffe1f SE	274	if (hard_iface->if_status == BATADV_IF_NOT_IN_USE \|\|
825ffe1f SE	275	hard_iface->if_status == BATADV_IF_TO_BE_REMOVED)
d6f94d91 LL	276	goto out;
	277
	278	/* the interface was enabled but may not be ready yet */
	279	if (hard_iface->if_status != BATADV_IF_ACTIVE)
	280	goto restart_timer;
	281
	282	skb = skb_copy(hard_iface->bat_v.elp_skb, GFP_ATOMIC);
	283	if (!skb)
	284	goto restart_timer;
	285
	286	elp_packet = (struct batadv_elp_packet *)skb->data;
	287	elp_packet->seqno = htonl(atomic_read(&hard_iface->bat_v.elp_seqno));
	288	elp_interval = atomic_read(&hard_iface->bat_v.elp_interval);
	289	elp_packet->elp_interval = htonl(elp_interval);
	290
	291	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
	292	"Sending broadcast ELP packet on interface %s, seqno %u\n",
	293	hard_iface->net_dev->name,
	294	atomic_read(&hard_iface->bat_v.elp_seqno));
	295
95d39278	296	batadv_send_broadcast_skb(skb, hard_iface);
d6f94d91 LL	297
	298	atomic_inc(&hard_iface->bat_v.elp_seqno);
	299
c833484e AQ	300	/* The throughput metric is updated on each sent packet. This way, if a
	301	* node is dead and no longer sends packets, batman-adv is still able to
	302	* react timely to its death.
	303	*
	304	* The throughput metric is updated by following these steps:
	305	* 1) if the hard_iface is wifi => send a number of unicast ELPs for
	306	* probing/sampling to each neighbor
	307	* 2) update the throughput metric value of each neighbor (note that the
	308	* value retrieved in this step might be 100ms old because the
	309	* probing packets at point 1) could still be in the HW queue)
	310	*/
	311	rcu_read_lock();
	312	hlist_for_each_entry_rcu(hardif_neigh, &hard_iface->neigh_list, list) {
8d2d499e AQ	313	if (!batadv_v_elp_wifi_neigh_probe(hardif_neigh))
	314	/* if something goes wrong while probing, better to stop
	315	* sending packets immediately and reschedule the task
	316	*/
	317	break;
	318
c833484e AQ	319	if (!kref_get_unless_zero(&hardif_neigh->refcount))
	320	continue;
	321
	322	/* Reading the estimated throughput from cfg80211 is a task that
	323	* may sleep and that is not allowed in an rcu protected
	324	* context. Therefore schedule a task for that.
	325	*/
4c4af690 ML	326	ret = queue_work(batadv_event_workqueue,
	327	&hardif_neigh->bat_v.metric_work);
	328
	329	if (!ret)
	330	batadv_hardif_neigh_put(hardif_neigh);
c833484e AQ	331	}
	332	rcu_read_unlock();
	333
d6f94d91 LL	334	restart_timer:
	335	batadv_v_elp_start_timer(hard_iface);
	336	out:
	337	return;
	338	}
	339
	340	/**
7e9a8c2c	341	* batadv_v_elp_iface_enable() - setup the ELP interface private resources
d6f94d91 LL	342	* @hard_iface: interface for which the data has to be prepared
	343	*
	344	* Return: 0 on success or a -ENOMEM in case of failure.
	345	*/
	346	int batadv_v_elp_iface_enable(struct batadv_hard_iface *hard_iface)
	347	{
f4156f96	348	static const size_t tvlv_padding = sizeof(__be32);
d6f94d91 LL	349	struct batadv_elp_packet *elp_packet;
	350	unsigned char *elp_buff;
	351	u32 random_seqno;
	352	size_t size;
	353	int res = -ENOMEM;
	354
f4156f96	355	size = ETH_HLEN + NET_IP_ALIGN + BATADV_ELP_HLEN + tvlv_padding;
d6f94d91 LL	356	hard_iface->bat_v.elp_skb = dev_alloc_skb(size);
	357	if (!hard_iface->bat_v.elp_skb)
	358	goto out;
	359
	360	skb_reserve(hard_iface->bat_v.elp_skb, ETH_HLEN + NET_IP_ALIGN);
f4156f96 SE	361	elp_buff = skb_put_zero(hard_iface->bat_v.elp_skb,
f4156f96 SE	362	BATADV_ELP_HLEN + tvlv_padding);
d6f94d91	363	elp_packet = (struct batadv_elp_packet *)elp_buff;
d6f94d91 LL	364
	365	elp_packet->packet_type = BATADV_ELP;
	366	elp_packet->version = BATADV_COMPAT_VERSION;
	367
	368	/* randomize initial seqno to avoid collision */
	369	get_random_bytes(&random_seqno, sizeof(random_seqno));
	370	atomic_set(&hard_iface->bat_v.elp_seqno, random_seqno);
d6f94d91	371
c833484e AQ	372	/* assume full-duplex by default */
	373	hard_iface->bat_v.flags \|= BATADV_FULL_DUPLEX;
	374
	375	/* warn the user (again) if there is no throughput data is available */
	376	hard_iface->bat_v.flags &= ~BATADV_WARNING_DEFAULT;
	377
10b1bbb4	378	if (batadv_is_wifi_hardif(hard_iface))
c833484e AQ	379	hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;
c833484e AQ	380
d6f94d91 LL	381	INIT_DELAYED_WORK(&hard_iface->bat_v.elp_wq,
	382	batadv_v_elp_periodic_work);
	383	batadv_v_elp_start_timer(hard_iface);
	384	res = 0;
	385
	386	out:
	387	return res;
	388	}
	389
	390	/**
7e9a8c2c	391	* batadv_v_elp_iface_disable() - release ELP interface private resources
d6f94d91 LL	392	* @hard_iface: interface for which the resources have to be released
	393	*/
	394	void batadv_v_elp_iface_disable(struct batadv_hard_iface *hard_iface)
	395	{
	396	cancel_delayed_work_sync(&hard_iface->bat_v.elp_wq);
	397
	398	dev_kfree_skb(hard_iface->bat_v.elp_skb);
	399	hard_iface->bat_v.elp_skb = NULL;
	400	}
	401
ebe24cea	402	/**
7e9a8c2c	403	* batadv_v_elp_iface_activate() - update the ELP buffer belonging to the given
ebe24cea ML	404	* hard-interface
	405	* @primary_iface: the new primary interface
	406	* @hard_iface: interface holding the to-be-updated buffer
	407	*/
	408	void batadv_v_elp_iface_activate(struct batadv_hard_iface *primary_iface,
	409	struct batadv_hard_iface *hard_iface)
	410	{
	411	struct batadv_elp_packet *elp_packet;
	412	struct sk_buff *skb;
	413
	414	if (!hard_iface->bat_v.elp_skb)
	415	return;
	416
	417	skb = hard_iface->bat_v.elp_skb;
	418	elp_packet = (struct batadv_elp_packet *)skb->data;
	419	ether_addr_copy(elp_packet->orig,
	420	primary_iface->net_dev->dev_addr);
	421	}
	422
d6f94d91	423	/**
7e9a8c2c	424	* batadv_v_elp_primary_iface_set() - change internal data to reflect the new
d6f94d91 LL	425	* primary interface
	426	* @primary_iface: the new primary interface
	427	*/
	428	void batadv_v_elp_primary_iface_set(struct batadv_hard_iface *primary_iface)
	429	{
	430	struct batadv_hard_iface *hard_iface;
d6f94d91 LL	431
	432	/* update orig field of every elp iface belonging to this mesh */
	433	rcu_read_lock();
	434	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
	435	if (primary_iface->soft_iface != hard_iface->soft_iface)
	436	continue;
	437
ebe24cea	438	batadv_v_elp_iface_activate(primary_iface, hard_iface);
d6f94d91 LL	439	}
	440	rcu_read_unlock();
	441	}
162bd64c	442
162bd64c	443	/**
7e9a8c2c	444	* batadv_v_elp_neigh_update() - update an ELP neighbour node
162bd64c LL	445	* @bat_priv: the bat priv with all the soft interface information
	446	* @neigh_addr: the neighbour interface address
	447	* @if_incoming: the interface the packet was received through
	448	* @elp_packet: the received ELP packet
	449	*
	450	* Updates the ELP neighbour node state with the data received within the new
	451	* ELP packet.
	452	*/
	453	static void batadv_v_elp_neigh_update(struct batadv_priv *bat_priv,
	454	u8 *neigh_addr,
	455	struct batadv_hard_iface *if_incoming,
	456	struct batadv_elp_packet *elp_packet)
	457
	458	{
	459	struct batadv_neigh_node *neigh;
	460	struct batadv_orig_node *orig_neigh;
	461	struct batadv_hardif_neigh_node *hardif_neigh;
	462	s32 seqno_diff;
	463	s32 elp_latest_seqno;
	464
	465	orig_neigh = batadv_v_ogm_orig_get(bat_priv, elp_packet->orig);
	466	if (!orig_neigh)
	467	return;
	468
6f0a6b5e ML	469	neigh = batadv_neigh_node_get_or_create(orig_neigh,
6f0a6b5e ML	470	if_incoming, neigh_addr);
162bd64c LL	471	if (!neigh)
	472	goto orig_free;
	473
	474	hardif_neigh = batadv_hardif_neigh_get(if_incoming, neigh_addr);
	475	if (!hardif_neigh)
	476	goto neigh_free;
	477
	478	elp_latest_seqno = hardif_neigh->bat_v.elp_latest_seqno;
	479	seqno_diff = ntohl(elp_packet->seqno) - elp_latest_seqno;
	480
	481	/* known or older sequence numbers are ignored. However always adopt
	482	* if the router seems to have been restarted.
	483	*/
	484	if (seqno_diff < 1 && seqno_diff > -BATADV_ELP_MAX_AGE)
	485	goto hardif_free;
	486
	487	neigh->last_seen = jiffies;
	488	hardif_neigh->last_seen = jiffies;
	489	hardif_neigh->bat_v.elp_latest_seqno = ntohl(elp_packet->seqno);
	490	hardif_neigh->bat_v.elp_interval = ntohl(elp_packet->elp_interval);
	491
	492	hardif_free:
	493	if (hardif_neigh)
	494	batadv_hardif_neigh_put(hardif_neigh);
	495	neigh_free:
	496	if (neigh)
	497	batadv_neigh_node_put(neigh);
	498	orig_free:
	499	if (orig_neigh)
	500	batadv_orig_node_put(orig_neigh);
	501	}
	502
	503	/**
7e9a8c2c	504	* batadv_v_elp_packet_recv() - main ELP packet handler
162bd64c LL	505	* @skb: the received packet
	506	* @if_incoming: the interface this packet was received through
	507	*
	508	* Return: NET_RX_SUCCESS and consumes the skb if the packet was peoperly
	509	* processed or NET_RX_DROP in case of failure.
	510	*/
	511	int batadv_v_elp_packet_recv(struct sk_buff *skb,
	512	struct batadv_hard_iface *if_incoming)
	513	{
	514	struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
	515	struct batadv_elp_packet *elp_packet;
	516	struct batadv_hard_iface *primary_if;
	517	struct ethhdr ethhdr = (struct ethhdr )skb_mac_header(skb);
b91a2543 SE	518	bool res;
b91a2543 SE	519	int ret = NET_RX_DROP;
162bd64c	520
b91a2543 SE	521	res = batadv_check_management_packet(skb, if_incoming, BATADV_ELP_HLEN);
	522	if (!res)
	523	goto free_skb;
162bd64c LL	524
162bd64c LL	525	if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
b91a2543	526	goto free_skb;
162bd64c LL	527
	528	/* did we receive a B.A.T.M.A.N. V ELP packet on an interface
	529	* that does not have B.A.T.M.A.N. V ELP enabled ?
	530	*/
29824a55	531	if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
b91a2543	532	goto free_skb;
162bd64c LL	533
	534	elp_packet = (struct batadv_elp_packet *)skb->data;
	535
	536	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
	537	"Received ELP packet from %pM seqno %u ORIG: %pM\n",
	538	ethhdr->h_source, ntohl(elp_packet->seqno),
	539	elp_packet->orig);
	540
	541	primary_if = batadv_primary_if_get_selected(bat_priv);
	542	if (!primary_if)
b91a2543	543	goto free_skb;
162bd64c LL	544
	545	batadv_v_elp_neigh_update(bat_priv, ethhdr->h_source, if_incoming,
	546	elp_packet);
	547
b91a2543 SE	548	ret = NET_RX_SUCCESS;
	549	batadv_hardif_put(primary_if);
	550
	551	free_skb:
	552	if (ret == NET_RX_SUCCESS)
	553	consume_skb(skb);
	554	else
	555	kfree_skb(skb);
	556
	557	return ret;
162bd64c	558	}