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

// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 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/minmax.h>
#include <linux/netdevice.h>
#include <linux/nl80211.h>
#include <linux/prandom.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_max(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 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))
			return sinfo.expected_throughput / 100;

		/* try to estimate the expected throughput based on reported tx
		 * rates
		 */
		if (sinfo.filled & BIT(NL80211_STA_INFO_TX_BITRATE))
			return cfg80211_calculate_bitrate(&sinfo.txrate) / 3;

		goto default_throughput;
	}

	/* 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 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 messages 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:
	batadv_hardif_neigh_put(hardif_neigh);
neigh_free:
	batadv_neigh_node_put(neigh);
orig_free:
	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 properly
 * 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
cfa55c6d	2	/* Copyright (C) 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>
fcd193e1	21	#include <linux/minmax.h>
d6f94d91	22	#include <linux/netdevice.h>
d6289088	23	#include <linux/nl80211.h>
0093870a	24	#include <linux/prandom.h>
d6f94d91 LL	25	#include <linux/random.h>
	26	#include <linux/rculist.h>
	27	#include <linux/rcupdate.h>
c833484e	28	#include <linux/rtnetlink.h>
d6f94d91 LL	29	#include <linux/skbuff.h>
	30	#include <linux/stddef.h>
	31	#include <linux/string.h>
	32	#include <linux/types.h>
	33	#include <linux/workqueue.h>
c833484e	34	#include <net/cfg80211.h>
fec149f5	35	#include <uapi/linux/batadv_packet.h>
d6f94d91 LL	36
d6f94d91 LL	37	#include "bat_algo.h"
9323158e	38	#include "bat_v_ogm.h"
d6f94d91	39	#include "hard-interface.h"
ba412080	40	#include "log.h"
162bd64c	41	#include "originator.h"
162bd64c	42	#include "routing.h"
d6f94d91 LL	43	#include "send.h"
	44
	45	/**
7e9a8c2c	46	* batadv_v_elp_start_timer() - restart timer for ELP periodic work
d6f94d91 LL	47	* @hard_iface: the interface for which the timer has to be reset
	48	*/
	49	static void batadv_v_elp_start_timer(struct batadv_hard_iface *hard_iface)
	50	{
	51	unsigned int msecs;
	52
	53	msecs = atomic_read(&hard_iface->bat_v.elp_interval) - BATADV_JITTER;
26893e7e	54	msecs += prandom_u32_max(2 * BATADV_JITTER);
d6f94d91 LL	55
	56	queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.elp_wq,
	57	msecs_to_jiffies(msecs));
	58	}
	59
c833484e	60	/**
7e9a8c2c	61	* batadv_v_elp_get_throughput() - get the throughput towards a neighbour
c833484e AQ	62	* @neigh: the neighbour for which the throughput has to be obtained
	63	*
	64	* Return: The throughput towards the given neighbour in multiples of 100kpbs
bccb48c8	65	* (a value of '1' equals 0.1Mbps, '10' equals 1Mbps, etc).
c833484e AQ	66	*/
	67	static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh)
	68	{
	69	struct batadv_hard_iface *hard_iface = neigh->if_incoming;
	70	struct ethtool_link_ksettings link_settings;
1942de1b	71	struct net_device *real_netdev;
c833484e AQ	72	struct station_info sinfo;
	73	u32 throughput;
	74	int ret;
	75
	76	/* if the user specified a customised value for this interface, then
	77	* return it directly
	78	*/
	79	throughput = atomic_read(&hard_iface->bat_v.throughput_override);
	80	if (throughput != 0)
	81	return throughput;
	82
	83	/* if this is a wireless device, then ask its throughput through
	84	* cfg80211 API
	85	*/
10b1bbb4 SE	86	if (batadv_is_wifi_hardif(hard_iface)) {
10b1bbb4 SE	87	if (!batadv_is_cfg80211_hardif(hard_iface))
f44a3ae9 ML	88	/* unsupported WiFi driver version */
f44a3ae9 ML	89	goto default_throughput;
c833484e	90
1942de1b ML	91	real_netdev = batadv_get_real_netdev(hard_iface->net_dev);
	92	if (!real_netdev)
	93	goto default_throughput;
	94
	95	ret = cfg80211_get_station(real_netdev, neigh->addr, &sinfo);
	96
ca8c3b92 AR	97	if (!ret) {
	98	/* free the TID stats immediately */
	99	cfg80211_sinfo_release_content(&sinfo);
	100	}
7d652669	101
1942de1b	102	dev_put(real_netdev);
f44a3ae9 ML	103	if (ret == -ENOENT) {
	104	/* Node is not associated anymore! It would be
	105	* possible to delete this neighbor. For now set
	106	* the throughput metric to 0.
	107	*/
	108	return 0;
	109	}
3f3f8732 SE	110	if (ret)
	111	goto default_throughput;
	112
2b1aa5a4 RT	113	if (sinfo.filled & BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT))
	114	return sinfo.expected_throughput / 100;
	115
	116	/* try to estimate the expected throughput based on reported tx
	117	* rates
	118	*/
	119	if (sinfo.filled & BIT(NL80211_STA_INFO_TX_BITRATE))
	120	return cfg80211_calculate_bitrate(&sinfo.txrate) / 3;
	121
	122	goto default_throughput;
c833484e AQ	123	}
	124
	125	/* if not a wifi interface, check if this device provides data via
	126	* ethtool (e.g. an Ethernet adapter)
	127	*/
	128	memset(&link_settings, 0, sizeof(link_settings));
	129	rtnl_lock();
	130	ret = __ethtool_get_link_ksettings(hard_iface->net_dev, &link_settings);
	131	rtnl_unlock();
9ad346c9	132	if (ret == 0) {
c833484e AQ	133	/* link characteristics might change over time */
	134	if (link_settings.base.duplex == DUPLEX_FULL)
	135	hard_iface->bat_v.flags \|= BATADV_FULL_DUPLEX;
	136	else
	137	hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;
	138
	139	throughput = link_settings.base.speed;
825ffe1f	140	if (throughput && throughput != SPEED_UNKNOWN)
c833484e AQ	141	return throughput * 10;
	142	}
	143
	144	default_throughput:
	145	if (!(hard_iface->bat_v.flags & BATADV_WARNING_DEFAULT)) {
	146	batadv_info(hard_iface->soft_iface,
	147	"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",
	148	hard_iface->net_dev->name,
	149	BATADV_THROUGHPUT_DEFAULT_VALUE / 10,
	150	BATADV_THROUGHPUT_DEFAULT_VALUE % 10);
	151	hard_iface->bat_v.flags \|= BATADV_WARNING_DEFAULT;
	152	}
	153
	154	/* if none of the above cases apply, return the base_throughput */
	155	return BATADV_THROUGHPUT_DEFAULT_VALUE;
	156	}
	157
	158	/**
7e9a8c2c SE	159	* batadv_v_elp_throughput_metric_update() - worker updating the throughput
7e9a8c2c SE	160	* metric of a single hop neighbour
c833484e AQ	161	* @work: the work queue item
	162	*/
	163	void batadv_v_elp_throughput_metric_update(struct work_struct *work)
	164	{
	165	struct batadv_hardif_neigh_node_bat_v *neigh_bat_v;
	166	struct batadv_hardif_neigh_node *neigh;
	167
	168	neigh_bat_v = container_of(work, struct batadv_hardif_neigh_node_bat_v,
	169	metric_work);
	170	neigh = container_of(neigh_bat_v, struct batadv_hardif_neigh_node,
	171	bat_v);
	172
	173	ewma_throughput_add(&neigh->bat_v.throughput,
	174	batadv_v_elp_get_throughput(neigh));
	175
	176	/* decrement refcounter to balance increment performed before scheduling
	177	* this task
	178	*/
	179	batadv_hardif_neigh_put(neigh);
	180	}
	181
8d2d499e	182	/**
7e9a8c2c	183	* batadv_v_elp_wifi_neigh_probe() - send link probing packets to a neighbour
8d2d499e AQ	184	* @neigh: the neighbour to probe
	185	*
	186	* Sends a predefined number of unicast wifi packets to a given neighbour in
	187	* order to trigger the throughput estimation on this link by the RC algorithm.
bccb48c8 SE	188	* Packets are sent only if there is not enough payload unicast traffic towards
bccb48c8 SE	189	* this neighbour..
8d2d499e AQ	190	*
	191	* Return: True on success and false in case of error during skb preparation.
	192	*/
	193	static bool
	194	batadv_v_elp_wifi_neigh_probe(struct batadv_hardif_neigh_node *neigh)
	195	{
	196	struct batadv_hard_iface *hard_iface = neigh->if_incoming;
	197	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
	198	unsigned long last_tx_diff;
	199	struct sk_buff *skb;
	200	int probe_len, i;
	201	int elp_skb_len;
	202
	203	/* this probing routine is for Wifi neighbours only */
10b1bbb4	204	if (!batadv_is_wifi_hardif(hard_iface))
8d2d499e AQ	205	return true;
	206
	207	/* probe the neighbor only if no unicast packets have been sent
	208	* to it in the last 100 milliseconds: this is the rate control
	209	* algorithm sampling interval (minstrel). In this way, if not
	210	* enough traffic has been sent to the neighbor, batman-adv can
	211	* generate 2 probe packets and push the RC algorithm to perform
	212	* the sampling
	213	*/
	214	last_tx_diff = jiffies_to_msecs(jiffies - neigh->bat_v.last_unicast_tx);
	215	if (last_tx_diff <= BATADV_ELP_PROBE_MAX_TX_DIFF)
	216	return true;
	217
	218	probe_len = max_t(int, sizeof(struct batadv_elp_packet),
	219	BATADV_ELP_MIN_PROBE_SIZE);
	220
	221	for (i = 0; i < BATADV_ELP_PROBES_PER_NODE; i++) {
	222	elp_skb_len = hard_iface->bat_v.elp_skb->len;
	223	skb = skb_copy_expand(hard_iface->bat_v.elp_skb, 0,
	224	probe_len - elp_skb_len,
	225	GFP_ATOMIC);
	226	if (!skb)
	227	return false;
	228
	229	/* Tell the skb to get as big as the allocated space (we want
	230	* the packet to be exactly of that size to make the link
	231	* throughput estimation effective.
	232	*/
88d0895d	233	skb_put_zero(skb, probe_len - hard_iface->bat_v.elp_skb->len);
8d2d499e AQ	234
	235	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
	236	"Sending unicast (probe) ELP packet on interface %s to %pM\n",
	237	hard_iface->net_dev->name, neigh->addr);
	238
	239	batadv_send_skb_packet(skb, hard_iface, neigh->addr);
	240	}
	241
	242	return true;
	243	}
	244
d6f94d91	245	/**
7e9a8c2c	246	* batadv_v_elp_periodic_work() - ELP periodic task per interface
d6f94d91 LL	247	* @work: work queue item
d6f94d91 LL	248	*
bccb48c8	249	* Emits broadcast ELP messages in regular intervals.
d6f94d91 LL	250	*/
	251	static void batadv_v_elp_periodic_work(struct work_struct *work)
	252	{
c833484e	253	struct batadv_hardif_neigh_node *hardif_neigh;
d6f94d91 LL	254	struct batadv_hard_iface *hard_iface;
	255	struct batadv_hard_iface_bat_v *bat_v;
	256	struct batadv_elp_packet *elp_packet;
	257	struct batadv_priv *bat_priv;
	258	struct sk_buff *skb;
	259	u32 elp_interval;
4c4af690	260	bool ret;
d6f94d91 LL	261
	262	bat_v = container_of(work, struct batadv_hard_iface_bat_v, elp_wq.work);
	263	hard_iface = container_of(bat_v, struct batadv_hard_iface, bat_v);
	264	bat_priv = netdev_priv(hard_iface->soft_iface);
	265
	266	if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
	267	goto out;
	268
	269	/* we are in the process of shutting this interface down */
825ffe1f SE	270	if (hard_iface->if_status == BATADV_IF_NOT_IN_USE \|\|
825ffe1f SE	271	hard_iface->if_status == BATADV_IF_TO_BE_REMOVED)
d6f94d91 LL	272	goto out;
	273
	274	/* the interface was enabled but may not be ready yet */
	275	if (hard_iface->if_status != BATADV_IF_ACTIVE)
	276	goto restart_timer;
	277
	278	skb = skb_copy(hard_iface->bat_v.elp_skb, GFP_ATOMIC);
	279	if (!skb)
	280	goto restart_timer;
	281
	282	elp_packet = (struct batadv_elp_packet *)skb->data;
	283	elp_packet->seqno = htonl(atomic_read(&hard_iface->bat_v.elp_seqno));
	284	elp_interval = atomic_read(&hard_iface->bat_v.elp_interval);
	285	elp_packet->elp_interval = htonl(elp_interval);
	286
	287	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
	288	"Sending broadcast ELP packet on interface %s, seqno %u\n",
	289	hard_iface->net_dev->name,
	290	atomic_read(&hard_iface->bat_v.elp_seqno));
	291
95d39278	292	batadv_send_broadcast_skb(skb, hard_iface);
d6f94d91 LL	293
	294	atomic_inc(&hard_iface->bat_v.elp_seqno);
	295
c833484e AQ	296	/* The throughput metric is updated on each sent packet. This way, if a
	297	* node is dead and no longer sends packets, batman-adv is still able to
	298	* react timely to its death.
	299	*
	300	* The throughput metric is updated by following these steps:
	301	* 1) if the hard_iface is wifi => send a number of unicast ELPs for
	302	* probing/sampling to each neighbor
	303	* 2) update the throughput metric value of each neighbor (note that the
	304	* value retrieved in this step might be 100ms old because the
	305	* probing packets at point 1) could still be in the HW queue)
	306	*/
	307	rcu_read_lock();
	308	hlist_for_each_entry_rcu(hardif_neigh, &hard_iface->neigh_list, list) {
8d2d499e AQ	309	if (!batadv_v_elp_wifi_neigh_probe(hardif_neigh))
	310	/* if something goes wrong while probing, better to stop
	311	* sending packets immediately and reschedule the task
	312	*/
	313	break;
	314
c833484e AQ	315	if (!kref_get_unless_zero(&hardif_neigh->refcount))
	316	continue;
	317
	318	/* Reading the estimated throughput from cfg80211 is a task that
	319	* may sleep and that is not allowed in an rcu protected
	320	* context. Therefore schedule a task for that.
	321	*/
4c4af690 ML	322	ret = queue_work(batadv_event_workqueue,
	323	&hardif_neigh->bat_v.metric_work);
	324
	325	if (!ret)
	326	batadv_hardif_neigh_put(hardif_neigh);
c833484e AQ	327	}
	328	rcu_read_unlock();
	329
d6f94d91 LL	330	restart_timer:
	331	batadv_v_elp_start_timer(hard_iface);
	332	out:
	333	return;
	334	}
	335
	336	/**
7e9a8c2c	337	* batadv_v_elp_iface_enable() - setup the ELP interface private resources
d6f94d91 LL	338	* @hard_iface: interface for which the data has to be prepared
	339	*
	340	* Return: 0 on success or a -ENOMEM in case of failure.
	341	*/
	342	int batadv_v_elp_iface_enable(struct batadv_hard_iface *hard_iface)
	343	{
f4156f96	344	static const size_t tvlv_padding = sizeof(__be32);
d6f94d91 LL	345	struct batadv_elp_packet *elp_packet;
	346	unsigned char *elp_buff;
	347	u32 random_seqno;
	348	size_t size;
	349	int res = -ENOMEM;
	350
f4156f96	351	size = ETH_HLEN + NET_IP_ALIGN + BATADV_ELP_HLEN + tvlv_padding;
d6f94d91 LL	352	hard_iface->bat_v.elp_skb = dev_alloc_skb(size);
	353	if (!hard_iface->bat_v.elp_skb)
	354	goto out;
	355
	356	skb_reserve(hard_iface->bat_v.elp_skb, ETH_HLEN + NET_IP_ALIGN);
f4156f96 SE	357	elp_buff = skb_put_zero(hard_iface->bat_v.elp_skb,
f4156f96 SE	358	BATADV_ELP_HLEN + tvlv_padding);
d6f94d91	359	elp_packet = (struct batadv_elp_packet *)elp_buff;
d6f94d91 LL	360
	361	elp_packet->packet_type = BATADV_ELP;
	362	elp_packet->version = BATADV_COMPAT_VERSION;
	363
	364	/* randomize initial seqno to avoid collision */
	365	get_random_bytes(&random_seqno, sizeof(random_seqno));
	366	atomic_set(&hard_iface->bat_v.elp_seqno, random_seqno);
d6f94d91	367
c833484e AQ	368	/* assume full-duplex by default */
	369	hard_iface->bat_v.flags \|= BATADV_FULL_DUPLEX;
	370
	371	/* warn the user (again) if there is no throughput data is available */
	372	hard_iface->bat_v.flags &= ~BATADV_WARNING_DEFAULT;
	373
10b1bbb4	374	if (batadv_is_wifi_hardif(hard_iface))
c833484e AQ	375	hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;
c833484e AQ	376
d6f94d91 LL	377	INIT_DELAYED_WORK(&hard_iface->bat_v.elp_wq,
	378	batadv_v_elp_periodic_work);
	379	batadv_v_elp_start_timer(hard_iface);
	380	res = 0;
	381
	382	out:
	383	return res;
	384	}
	385
	386	/**
7e9a8c2c	387	* batadv_v_elp_iface_disable() - release ELP interface private resources
d6f94d91 LL	388	* @hard_iface: interface for which the resources have to be released
	389	*/
	390	void batadv_v_elp_iface_disable(struct batadv_hard_iface *hard_iface)
	391	{
	392	cancel_delayed_work_sync(&hard_iface->bat_v.elp_wq);
	393
	394	dev_kfree_skb(hard_iface->bat_v.elp_skb);
	395	hard_iface->bat_v.elp_skb = NULL;
	396	}
	397
ebe24cea	398	/**
7e9a8c2c	399	* batadv_v_elp_iface_activate() - update the ELP buffer belonging to the given
ebe24cea ML	400	* hard-interface
	401	* @primary_iface: the new primary interface
	402	* @hard_iface: interface holding the to-be-updated buffer
	403	*/
	404	void batadv_v_elp_iface_activate(struct batadv_hard_iface *primary_iface,
	405	struct batadv_hard_iface *hard_iface)
	406	{
	407	struct batadv_elp_packet *elp_packet;
	408	struct sk_buff *skb;
	409
	410	if (!hard_iface->bat_v.elp_skb)
	411	return;
	412
	413	skb = hard_iface->bat_v.elp_skb;
	414	elp_packet = (struct batadv_elp_packet *)skb->data;
	415	ether_addr_copy(elp_packet->orig,
	416	primary_iface->net_dev->dev_addr);
	417	}
	418
d6f94d91	419	/**
7e9a8c2c	420	* batadv_v_elp_primary_iface_set() - change internal data to reflect the new
d6f94d91 LL	421	* primary interface
	422	* @primary_iface: the new primary interface
	423	*/
	424	void batadv_v_elp_primary_iface_set(struct batadv_hard_iface *primary_iface)
	425	{
	426	struct batadv_hard_iface *hard_iface;
d6f94d91 LL	427
	428	/* update orig field of every elp iface belonging to this mesh */
	429	rcu_read_lock();
	430	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
	431	if (primary_iface->soft_iface != hard_iface->soft_iface)
	432	continue;
	433
ebe24cea	434	batadv_v_elp_iface_activate(primary_iface, hard_iface);
d6f94d91 LL	435	}
	436	rcu_read_unlock();
	437	}
162bd64c	438
162bd64c	439	/**
7e9a8c2c	440	* batadv_v_elp_neigh_update() - update an ELP neighbour node
162bd64c LL	441	* @bat_priv: the bat priv with all the soft interface information
	442	* @neigh_addr: the neighbour interface address
	443	* @if_incoming: the interface the packet was received through
	444	* @elp_packet: the received ELP packet
	445	*
	446	* Updates the ELP neighbour node state with the data received within the new
	447	* ELP packet.
	448	*/
	449	static void batadv_v_elp_neigh_update(struct batadv_priv *bat_priv,
	450	u8 *neigh_addr,
	451	struct batadv_hard_iface *if_incoming,
	452	struct batadv_elp_packet *elp_packet)
	453
	454	{
	455	struct batadv_neigh_node *neigh;
	456	struct batadv_orig_node *orig_neigh;
	457	struct batadv_hardif_neigh_node *hardif_neigh;
	458	s32 seqno_diff;
	459	s32 elp_latest_seqno;
	460
	461	orig_neigh = batadv_v_ogm_orig_get(bat_priv, elp_packet->orig);
	462	if (!orig_neigh)
	463	return;
	464
6f0a6b5e ML	465	neigh = batadv_neigh_node_get_or_create(orig_neigh,
6f0a6b5e ML	466	if_incoming, neigh_addr);
162bd64c LL	467	if (!neigh)
	468	goto orig_free;
	469
	470	hardif_neigh = batadv_hardif_neigh_get(if_incoming, neigh_addr);
	471	if (!hardif_neigh)
	472	goto neigh_free;
	473
	474	elp_latest_seqno = hardif_neigh->bat_v.elp_latest_seqno;
	475	seqno_diff = ntohl(elp_packet->seqno) - elp_latest_seqno;
	476
	477	/* known or older sequence numbers are ignored. However always adopt
	478	* if the router seems to have been restarted.
	479	*/
	480	if (seqno_diff < 1 && seqno_diff > -BATADV_ELP_MAX_AGE)
	481	goto hardif_free;
	482
	483	neigh->last_seen = jiffies;
	484	hardif_neigh->last_seen = jiffies;
	485	hardif_neigh->bat_v.elp_latest_seqno = ntohl(elp_packet->seqno);
	486	hardif_neigh->bat_v.elp_interval = ntohl(elp_packet->elp_interval);
	487
	488	hardif_free:
79a0bffb	489	batadv_hardif_neigh_put(hardif_neigh);
162bd64c	490	neigh_free:
79a0bffb	491	batadv_neigh_node_put(neigh);
162bd64c	492	orig_free:
79a0bffb	493	batadv_orig_node_put(orig_neigh);
162bd64c LL	494	}
	495
	496	/**
7e9a8c2c	497	* batadv_v_elp_packet_recv() - main ELP packet handler
162bd64c LL	498	* @skb: the received packet
	499	* @if_incoming: the interface this packet was received through
	500	*
bccb48c8	501	* Return: NET_RX_SUCCESS and consumes the skb if the packet was properly
162bd64c LL	502	* processed or NET_RX_DROP in case of failure.
	503	*/
	504	int batadv_v_elp_packet_recv(struct sk_buff *skb,
	505	struct batadv_hard_iface *if_incoming)
	506	{
	507	struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
	508	struct batadv_elp_packet *elp_packet;
	509	struct batadv_hard_iface *primary_if;
	510	struct ethhdr ethhdr = (struct ethhdr )skb_mac_header(skb);
b91a2543 SE	511	bool res;
b91a2543 SE	512	int ret = NET_RX_DROP;
162bd64c	513
b91a2543 SE	514	res = batadv_check_management_packet(skb, if_incoming, BATADV_ELP_HLEN);
	515	if (!res)
	516	goto free_skb;
162bd64c LL	517
162bd64c LL	518	if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
b91a2543	519	goto free_skb;
162bd64c LL	520
	521	/* did we receive a B.A.T.M.A.N. V ELP packet on an interface
	522	* that does not have B.A.T.M.A.N. V ELP enabled ?
	523	*/
29824a55	524	if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
b91a2543	525	goto free_skb;
162bd64c LL	526
	527	elp_packet = (struct batadv_elp_packet *)skb->data;
	528
	529	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
	530	"Received ELP packet from %pM seqno %u ORIG: %pM\n",
	531	ethhdr->h_source, ntohl(elp_packet->seqno),
	532	elp_packet->orig);
	533
	534	primary_if = batadv_primary_if_get_selected(bat_priv);
	535	if (!primary_if)
b91a2543	536	goto free_skb;
162bd64c LL	537
	538	batadv_v_elp_neigh_update(bat_priv, ethhdr->h_source, if_incoming,
	539	elp_packet);
	540
b91a2543 SE	541	ret = NET_RX_SUCCESS;
	542	batadv_hardif_put(primary_if);
	543
	544	free_skb:
	545	if (ret == NET_RX_SUCCESS)
	546	consume_skb(skb);
	547	else
	548	kfree_skb(skb);
	549
	550	return ret;
162bd64c	551	}