1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2011-2018 B.A.T.M.A.N. contributors:
4 * Linus Lüssing, Marek Lindner
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of version 2 of the GNU General Public
8 * License as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, see <http://www.gnu.org/licenses/>.
19 #include "bat_v_elp.h"
22 #include <linux/atomic.h>
23 #include <linux/bitops.h>
24 #include <linux/byteorder/generic.h>
25 #include <linux/errno.h>
26 #include <linux/etherdevice.h>
27 #include <linux/ethtool.h>
28 #include <linux/gfp.h>
29 #include <linux/if_ether.h>
30 #include <linux/jiffies.h>
31 #include <linux/kernel.h>
32 #include <linux/kref.h>
33 #include <linux/netdevice.h>
34 #include <linux/nl80211.h>
35 #include <linux/random.h>
36 #include <linux/rculist.h>
37 #include <linux/rcupdate.h>
38 #include <linux/rtnetlink.h>
39 #include <linux/skbuff.h>
40 #include <linux/stddef.h>
41 #include <linux/string.h>
42 #include <linux/types.h>
43 #include <linux/workqueue.h>
44 #include <net/cfg80211.h>
45 #include <uapi/linux/batadv_packet.h>
48 #include "bat_v_ogm.h"
49 #include "hard-interface.h"
51 #include "originator.h"
56 * batadv_v_elp_start_timer() - restart timer for ELP periodic work
57 * @hard_iface: the interface for which the timer has to be reset
59 static void batadv_v_elp_start_timer(struct batadv_hard_iface *hard_iface)
63 msecs = atomic_read(&hard_iface->bat_v.elp_interval) - BATADV_JITTER;
64 msecs += prandom_u32() % (2 * BATADV_JITTER);
66 queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.elp_wq,
67 msecs_to_jiffies(msecs));
71 * batadv_v_elp_get_throughput() - get the throughput towards a neighbour
72 * @neigh: the neighbour for which the throughput has to be obtained
74 * Return: The throughput towards the given neighbour in multiples of 100kpbs
75 * (a value of '1' equals to 0.1Mbps, '10' equals 1Mbps, etc).
77 static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh)
79 struct batadv_hard_iface *hard_iface = neigh->if_incoming;
80 struct ethtool_link_ksettings link_settings;
81 struct net_device *real_netdev;
82 struct station_info sinfo;
86 /* if the user specified a customised value for this interface, then
89 throughput = atomic_read(&hard_iface->bat_v.throughput_override);
93 /* if this is a wireless device, then ask its throughput through
96 if (batadv_is_wifi_hardif(hard_iface)) {
97 if (!batadv_is_cfg80211_hardif(hard_iface))
98 /* unsupported WiFi driver version */
99 goto default_throughput;
101 real_netdev = batadv_get_real_netdev(hard_iface->net_dev);
103 goto default_throughput;
105 ret = cfg80211_get_station(real_netdev, neigh->addr, &sinfo);
107 dev_put(real_netdev);
108 if (ret == -ENOENT) {
109 /* Node is not associated anymore! It would be
110 * possible to delete this neighbor. For now set
111 * the throughput metric to 0.
116 goto default_throughput;
117 if (!(sinfo.filled & BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT)))
118 goto default_throughput;
120 return sinfo.expected_throughput / 100;
123 /* if not a wifi interface, check if this device provides data via
124 * ethtool (e.g. an Ethernet adapter)
126 memset(&link_settings, 0, sizeof(link_settings));
128 ret = __ethtool_get_link_ksettings(hard_iface->net_dev, &link_settings);
131 /* Virtual interface drivers such as tun / tap interfaces, VLAN, etc
132 * tend to initialize the interface throughput with some value for the
133 * sake of having a throughput number to export via ethtool. This
134 * exported throughput leaves batman-adv to conclude the interface
135 * throughput is genuine (reflecting reality), thus no measurements
138 * Based on the observation that those interface types also tend to set
139 * the link auto-negotiation to 'off', batman-adv shall check this
140 * setting to differentiate between genuine link throughput information
141 * and placeholders installed by virtual interfaces.
143 if (ret == 0 && link_settings.base.autoneg == AUTONEG_ENABLE) {
144 /* link characteristics might change over time */
145 if (link_settings.base.duplex == DUPLEX_FULL)
146 hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX;
148 hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;
150 throughput = link_settings.base.speed;
151 if (throughput && throughput != SPEED_UNKNOWN)
152 return throughput * 10;
156 if (!(hard_iface->bat_v.flags & BATADV_WARNING_DEFAULT)) {
157 batadv_info(hard_iface->soft_iface,
158 "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",
159 hard_iface->net_dev->name,
160 BATADV_THROUGHPUT_DEFAULT_VALUE / 10,
161 BATADV_THROUGHPUT_DEFAULT_VALUE % 10);
162 hard_iface->bat_v.flags |= BATADV_WARNING_DEFAULT;
165 /* if none of the above cases apply, return the base_throughput */
166 return BATADV_THROUGHPUT_DEFAULT_VALUE;
170 * batadv_v_elp_throughput_metric_update() - worker updating the throughput
171 * metric of a single hop neighbour
172 * @work: the work queue item
174 void batadv_v_elp_throughput_metric_update(struct work_struct *work)
176 struct batadv_hardif_neigh_node_bat_v *neigh_bat_v;
177 struct batadv_hardif_neigh_node *neigh;
179 neigh_bat_v = container_of(work, struct batadv_hardif_neigh_node_bat_v,
181 neigh = container_of(neigh_bat_v, struct batadv_hardif_neigh_node,
184 ewma_throughput_add(&neigh->bat_v.throughput,
185 batadv_v_elp_get_throughput(neigh));
187 /* decrement refcounter to balance increment performed before scheduling
190 batadv_hardif_neigh_put(neigh);
194 * batadv_v_elp_wifi_neigh_probe() - send link probing packets to a neighbour
195 * @neigh: the neighbour to probe
197 * Sends a predefined number of unicast wifi packets to a given neighbour in
198 * order to trigger the throughput estimation on this link by the RC algorithm.
199 * Packets are sent only if there there is not enough payload unicast traffic
200 * towards this neighbour..
202 * Return: True on success and false in case of error during skb preparation.
205 batadv_v_elp_wifi_neigh_probe(struct batadv_hardif_neigh_node *neigh)
207 struct batadv_hard_iface *hard_iface = neigh->if_incoming;
208 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
209 unsigned long last_tx_diff;
214 /* this probing routine is for Wifi neighbours only */
215 if (!batadv_is_wifi_hardif(hard_iface))
218 /* probe the neighbor only if no unicast packets have been sent
219 * to it in the last 100 milliseconds: this is the rate control
220 * algorithm sampling interval (minstrel). In this way, if not
221 * enough traffic has been sent to the neighbor, batman-adv can
222 * generate 2 probe packets and push the RC algorithm to perform
225 last_tx_diff = jiffies_to_msecs(jiffies - neigh->bat_v.last_unicast_tx);
226 if (last_tx_diff <= BATADV_ELP_PROBE_MAX_TX_DIFF)
229 probe_len = max_t(int, sizeof(struct batadv_elp_packet),
230 BATADV_ELP_MIN_PROBE_SIZE);
232 for (i = 0; i < BATADV_ELP_PROBES_PER_NODE; i++) {
233 elp_skb_len = hard_iface->bat_v.elp_skb->len;
234 skb = skb_copy_expand(hard_iface->bat_v.elp_skb, 0,
235 probe_len - elp_skb_len,
240 /* Tell the skb to get as big as the allocated space (we want
241 * the packet to be exactly of that size to make the link
242 * throughput estimation effective.
244 skb_put(skb, probe_len - hard_iface->bat_v.elp_skb->len);
246 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
247 "Sending unicast (probe) ELP packet on interface %s to %pM\n",
248 hard_iface->net_dev->name, neigh->addr);
250 batadv_send_skb_packet(skb, hard_iface, neigh->addr);
257 * batadv_v_elp_periodic_work() - ELP periodic task per interface
258 * @work: work queue item
260 * Emits broadcast ELP message in regular intervals.
262 static void batadv_v_elp_periodic_work(struct work_struct *work)
264 struct batadv_hardif_neigh_node *hardif_neigh;
265 struct batadv_hard_iface *hard_iface;
266 struct batadv_hard_iface_bat_v *bat_v;
267 struct batadv_elp_packet *elp_packet;
268 struct batadv_priv *bat_priv;
272 bat_v = container_of(work, struct batadv_hard_iface_bat_v, elp_wq.work);
273 hard_iface = container_of(bat_v, struct batadv_hard_iface, bat_v);
274 bat_priv = netdev_priv(hard_iface->soft_iface);
276 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
279 /* we are in the process of shutting this interface down */
280 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE ||
281 hard_iface->if_status == BATADV_IF_TO_BE_REMOVED)
284 /* the interface was enabled but may not be ready yet */
285 if (hard_iface->if_status != BATADV_IF_ACTIVE)
288 skb = skb_copy(hard_iface->bat_v.elp_skb, GFP_ATOMIC);
292 elp_packet = (struct batadv_elp_packet *)skb->data;
293 elp_packet->seqno = htonl(atomic_read(&hard_iface->bat_v.elp_seqno));
294 elp_interval = atomic_read(&hard_iface->bat_v.elp_interval);
295 elp_packet->elp_interval = htonl(elp_interval);
297 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
298 "Sending broadcast ELP packet on interface %s, seqno %u\n",
299 hard_iface->net_dev->name,
300 atomic_read(&hard_iface->bat_v.elp_seqno));
302 batadv_send_broadcast_skb(skb, hard_iface);
304 atomic_inc(&hard_iface->bat_v.elp_seqno);
306 /* The throughput metric is updated on each sent packet. This way, if a
307 * node is dead and no longer sends packets, batman-adv is still able to
308 * react timely to its death.
310 * The throughput metric is updated by following these steps:
311 * 1) if the hard_iface is wifi => send a number of unicast ELPs for
312 * probing/sampling to each neighbor
313 * 2) update the throughput metric value of each neighbor (note that the
314 * value retrieved in this step might be 100ms old because the
315 * probing packets at point 1) could still be in the HW queue)
318 hlist_for_each_entry_rcu(hardif_neigh, &hard_iface->neigh_list, list) {
319 if (!batadv_v_elp_wifi_neigh_probe(hardif_neigh))
320 /* if something goes wrong while probing, better to stop
321 * sending packets immediately and reschedule the task
325 if (!kref_get_unless_zero(&hardif_neigh->refcount))
328 /* Reading the estimated throughput from cfg80211 is a task that
329 * may sleep and that is not allowed in an rcu protected
330 * context. Therefore schedule a task for that.
332 queue_work(batadv_event_workqueue,
333 &hardif_neigh->bat_v.metric_work);
338 batadv_v_elp_start_timer(hard_iface);
344 * batadv_v_elp_iface_enable() - setup the ELP interface private resources
345 * @hard_iface: interface for which the data has to be prepared
347 * Return: 0 on success or a -ENOMEM in case of failure.
349 int batadv_v_elp_iface_enable(struct batadv_hard_iface *hard_iface)
351 struct batadv_elp_packet *elp_packet;
352 unsigned char *elp_buff;
357 size = ETH_HLEN + NET_IP_ALIGN + BATADV_ELP_HLEN;
358 hard_iface->bat_v.elp_skb = dev_alloc_skb(size);
359 if (!hard_iface->bat_v.elp_skb)
362 skb_reserve(hard_iface->bat_v.elp_skb, ETH_HLEN + NET_IP_ALIGN);
363 elp_buff = skb_put_zero(hard_iface->bat_v.elp_skb, BATADV_ELP_HLEN);
364 elp_packet = (struct batadv_elp_packet *)elp_buff;
366 elp_packet->packet_type = BATADV_ELP;
367 elp_packet->version = BATADV_COMPAT_VERSION;
369 /* randomize initial seqno to avoid collision */
370 get_random_bytes(&random_seqno, sizeof(random_seqno));
371 atomic_set(&hard_iface->bat_v.elp_seqno, random_seqno);
373 /* assume full-duplex by default */
374 hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX;
376 /* warn the user (again) if there is no throughput data is available */
377 hard_iface->bat_v.flags &= ~BATADV_WARNING_DEFAULT;
379 if (batadv_is_wifi_hardif(hard_iface))
380 hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;
382 INIT_DELAYED_WORK(&hard_iface->bat_v.elp_wq,
383 batadv_v_elp_periodic_work);
384 batadv_v_elp_start_timer(hard_iface);
392 * batadv_v_elp_iface_disable() - release ELP interface private resources
393 * @hard_iface: interface for which the resources have to be released
395 void batadv_v_elp_iface_disable(struct batadv_hard_iface *hard_iface)
397 cancel_delayed_work_sync(&hard_iface->bat_v.elp_wq);
399 dev_kfree_skb(hard_iface->bat_v.elp_skb);
400 hard_iface->bat_v.elp_skb = NULL;
404 * batadv_v_elp_iface_activate() - update the ELP buffer belonging to the given
406 * @primary_iface: the new primary interface
407 * @hard_iface: interface holding the to-be-updated buffer
409 void batadv_v_elp_iface_activate(struct batadv_hard_iface *primary_iface,
410 struct batadv_hard_iface *hard_iface)
412 struct batadv_elp_packet *elp_packet;
415 if (!hard_iface->bat_v.elp_skb)
418 skb = hard_iface->bat_v.elp_skb;
419 elp_packet = (struct batadv_elp_packet *)skb->data;
420 ether_addr_copy(elp_packet->orig,
421 primary_iface->net_dev->dev_addr);
425 * batadv_v_elp_primary_iface_set() - change internal data to reflect the new
427 * @primary_iface: the new primary interface
429 void batadv_v_elp_primary_iface_set(struct batadv_hard_iface *primary_iface)
431 struct batadv_hard_iface *hard_iface;
433 /* update orig field of every elp iface belonging to this mesh */
435 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
436 if (primary_iface->soft_iface != hard_iface->soft_iface)
439 batadv_v_elp_iface_activate(primary_iface, hard_iface);
445 * batadv_v_elp_neigh_update() - update an ELP neighbour node
446 * @bat_priv: the bat priv with all the soft interface information
447 * @neigh_addr: the neighbour interface address
448 * @if_incoming: the interface the packet was received through
449 * @elp_packet: the received ELP packet
451 * Updates the ELP neighbour node state with the data received within the new
454 static void batadv_v_elp_neigh_update(struct batadv_priv *bat_priv,
456 struct batadv_hard_iface *if_incoming,
457 struct batadv_elp_packet *elp_packet)
460 struct batadv_neigh_node *neigh;
461 struct batadv_orig_node *orig_neigh;
462 struct batadv_hardif_neigh_node *hardif_neigh;
464 s32 elp_latest_seqno;
466 orig_neigh = batadv_v_ogm_orig_get(bat_priv, elp_packet->orig);
470 neigh = batadv_neigh_node_get_or_create(orig_neigh,
471 if_incoming, neigh_addr);
475 hardif_neigh = batadv_hardif_neigh_get(if_incoming, neigh_addr);
479 elp_latest_seqno = hardif_neigh->bat_v.elp_latest_seqno;
480 seqno_diff = ntohl(elp_packet->seqno) - elp_latest_seqno;
482 /* known or older sequence numbers are ignored. However always adopt
483 * if the router seems to have been restarted.
485 if (seqno_diff < 1 && seqno_diff > -BATADV_ELP_MAX_AGE)
488 neigh->last_seen = jiffies;
489 hardif_neigh->last_seen = jiffies;
490 hardif_neigh->bat_v.elp_latest_seqno = ntohl(elp_packet->seqno);
491 hardif_neigh->bat_v.elp_interval = ntohl(elp_packet->elp_interval);
495 batadv_hardif_neigh_put(hardif_neigh);
498 batadv_neigh_node_put(neigh);
501 batadv_orig_node_put(orig_neigh);
505 * batadv_v_elp_packet_recv() - main ELP packet handler
506 * @skb: the received packet
507 * @if_incoming: the interface this packet was received through
509 * Return: NET_RX_SUCCESS and consumes the skb if the packet was peoperly
510 * processed or NET_RX_DROP in case of failure.
512 int batadv_v_elp_packet_recv(struct sk_buff *skb,
513 struct batadv_hard_iface *if_incoming)
515 struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
516 struct batadv_elp_packet *elp_packet;
517 struct batadv_hard_iface *primary_if;
518 struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
520 int ret = NET_RX_DROP;
522 res = batadv_check_management_packet(skb, if_incoming, BATADV_ELP_HLEN);
526 if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
529 /* did we receive a B.A.T.M.A.N. V ELP packet on an interface
530 * that does not have B.A.T.M.A.N. V ELP enabled ?
532 if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
535 elp_packet = (struct batadv_elp_packet *)skb->data;
537 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
538 "Received ELP packet from %pM seqno %u ORIG: %pM\n",
539 ethhdr->h_source, ntohl(elp_packet->seqno),
542 primary_if = batadv_primary_if_get_selected(bat_priv);
546 batadv_v_elp_neigh_update(bat_priv, ethhdr->h_source, if_incoming,
549 ret = NET_RX_SUCCESS;
550 batadv_hardif_put(primary_if);
553 if (ret == NET_RX_SUCCESS)