1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2011-2020 B.A.T.M.A.N. contributors:
4 * Linus Lüssing, Marek Lindner
10 #include <linux/atomic.h>
11 #include <linux/bitops.h>
12 #include <linux/byteorder/generic.h>
13 #include <linux/errno.h>
14 #include <linux/etherdevice.h>
15 #include <linux/ethtool.h>
16 #include <linux/gfp.h>
17 #include <linux/if_ether.h>
18 #include <linux/jiffies.h>
19 #include <linux/kernel.h>
20 #include <linux/kref.h>
21 #include <linux/netdevice.h>
22 #include <linux/nl80211.h>
23 #include <linux/prandom.h>
24 #include <linux/random.h>
25 #include <linux/rculist.h>
26 #include <linux/rcupdate.h>
27 #include <linux/rtnetlink.h>
28 #include <linux/skbuff.h>
29 #include <linux/stddef.h>
30 #include <linux/string.h>
31 #include <linux/types.h>
32 #include <linux/workqueue.h>
33 #include <net/cfg80211.h>
34 #include <uapi/linux/batadv_packet.h>
37 #include "bat_v_ogm.h"
38 #include "hard-interface.h"
40 #include "originator.h"
45 * batadv_v_elp_start_timer() - restart timer for ELP periodic work
46 * @hard_iface: the interface for which the timer has to be reset
48 static void batadv_v_elp_start_timer(struct batadv_hard_iface *hard_iface)
52 msecs = atomic_read(&hard_iface->bat_v.elp_interval) - BATADV_JITTER;
53 msecs += prandom_u32_max(2 * BATADV_JITTER);
55 queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.elp_wq,
56 msecs_to_jiffies(msecs));
60 * batadv_v_elp_get_throughput() - get the throughput towards a neighbour
61 * @neigh: the neighbour for which the throughput has to be obtained
63 * Return: The throughput towards the given neighbour in multiples of 100kpbs
64 * (a value of '1' equals 0.1Mbps, '10' equals 1Mbps, etc).
66 static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh)
68 struct batadv_hard_iface *hard_iface = neigh->if_incoming;
69 struct ethtool_link_ksettings link_settings;
70 struct net_device *real_netdev;
71 struct station_info sinfo;
75 /* if the user specified a customised value for this interface, then
78 throughput = atomic_read(&hard_iface->bat_v.throughput_override);
82 /* if this is a wireless device, then ask its throughput through
85 if (batadv_is_wifi_hardif(hard_iface)) {
86 if (!batadv_is_cfg80211_hardif(hard_iface))
87 /* unsupported WiFi driver version */
88 goto default_throughput;
90 real_netdev = batadv_get_real_netdev(hard_iface->net_dev);
92 goto default_throughput;
94 ret = cfg80211_get_station(real_netdev, neigh->addr, &sinfo);
97 /* free the TID stats immediately */
98 cfg80211_sinfo_release_content(&sinfo);
101 dev_put(real_netdev);
102 if (ret == -ENOENT) {
103 /* Node is not associated anymore! It would be
104 * possible to delete this neighbor. For now set
105 * the throughput metric to 0.
110 goto default_throughput;
112 if (sinfo.filled & BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT))
113 return sinfo.expected_throughput / 100;
115 /* try to estimate the expected throughput based on reported tx
118 if (sinfo.filled & BIT(NL80211_STA_INFO_TX_BITRATE))
119 return cfg80211_calculate_bitrate(&sinfo.txrate) / 3;
121 goto default_throughput;
124 /* if not a wifi interface, check if this device provides data via
125 * ethtool (e.g. an Ethernet adapter)
127 memset(&link_settings, 0, sizeof(link_settings));
129 ret = __ethtool_get_link_ksettings(hard_iface->net_dev, &link_settings);
132 /* link characteristics might change over time */
133 if (link_settings.base.duplex == DUPLEX_FULL)
134 hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX;
136 hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;
138 throughput = link_settings.base.speed;
139 if (throughput && throughput != SPEED_UNKNOWN)
140 return throughput * 10;
144 if (!(hard_iface->bat_v.flags & BATADV_WARNING_DEFAULT)) {
145 batadv_info(hard_iface->soft_iface,
146 "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",
147 hard_iface->net_dev->name,
148 BATADV_THROUGHPUT_DEFAULT_VALUE / 10,
149 BATADV_THROUGHPUT_DEFAULT_VALUE % 10);
150 hard_iface->bat_v.flags |= BATADV_WARNING_DEFAULT;
153 /* if none of the above cases apply, return the base_throughput */
154 return BATADV_THROUGHPUT_DEFAULT_VALUE;
158 * batadv_v_elp_throughput_metric_update() - worker updating the throughput
159 * metric of a single hop neighbour
160 * @work: the work queue item
162 void batadv_v_elp_throughput_metric_update(struct work_struct *work)
164 struct batadv_hardif_neigh_node_bat_v *neigh_bat_v;
165 struct batadv_hardif_neigh_node *neigh;
167 neigh_bat_v = container_of(work, struct batadv_hardif_neigh_node_bat_v,
169 neigh = container_of(neigh_bat_v, struct batadv_hardif_neigh_node,
172 ewma_throughput_add(&neigh->bat_v.throughput,
173 batadv_v_elp_get_throughput(neigh));
175 /* decrement refcounter to balance increment performed before scheduling
178 batadv_hardif_neigh_put(neigh);
182 * batadv_v_elp_wifi_neigh_probe() - send link probing packets to a neighbour
183 * @neigh: the neighbour to probe
185 * Sends a predefined number of unicast wifi packets to a given neighbour in
186 * order to trigger the throughput estimation on this link by the RC algorithm.
187 * Packets are sent only if there is not enough payload unicast traffic towards
190 * Return: True on success and false in case of error during skb preparation.
193 batadv_v_elp_wifi_neigh_probe(struct batadv_hardif_neigh_node *neigh)
195 struct batadv_hard_iface *hard_iface = neigh->if_incoming;
196 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
197 unsigned long last_tx_diff;
202 /* this probing routine is for Wifi neighbours only */
203 if (!batadv_is_wifi_hardif(hard_iface))
206 /* probe the neighbor only if no unicast packets have been sent
207 * to it in the last 100 milliseconds: this is the rate control
208 * algorithm sampling interval (minstrel). In this way, if not
209 * enough traffic has been sent to the neighbor, batman-adv can
210 * generate 2 probe packets and push the RC algorithm to perform
213 last_tx_diff = jiffies_to_msecs(jiffies - neigh->bat_v.last_unicast_tx);
214 if (last_tx_diff <= BATADV_ELP_PROBE_MAX_TX_DIFF)
217 probe_len = max_t(int, sizeof(struct batadv_elp_packet),
218 BATADV_ELP_MIN_PROBE_SIZE);
220 for (i = 0; i < BATADV_ELP_PROBES_PER_NODE; i++) {
221 elp_skb_len = hard_iface->bat_v.elp_skb->len;
222 skb = skb_copy_expand(hard_iface->bat_v.elp_skb, 0,
223 probe_len - elp_skb_len,
228 /* Tell the skb to get as big as the allocated space (we want
229 * the packet to be exactly of that size to make the link
230 * throughput estimation effective.
232 skb_put_zero(skb, probe_len - hard_iface->bat_v.elp_skb->len);
234 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
235 "Sending unicast (probe) ELP packet on interface %s to %pM\n",
236 hard_iface->net_dev->name, neigh->addr);
238 batadv_send_skb_packet(skb, hard_iface, neigh->addr);
245 * batadv_v_elp_periodic_work() - ELP periodic task per interface
246 * @work: work queue item
248 * Emits broadcast ELP messages in regular intervals.
250 static void batadv_v_elp_periodic_work(struct work_struct *work)
252 struct batadv_hardif_neigh_node *hardif_neigh;
253 struct batadv_hard_iface *hard_iface;
254 struct batadv_hard_iface_bat_v *bat_v;
255 struct batadv_elp_packet *elp_packet;
256 struct batadv_priv *bat_priv;
261 bat_v = container_of(work, struct batadv_hard_iface_bat_v, elp_wq.work);
262 hard_iface = container_of(bat_v, struct batadv_hard_iface, bat_v);
263 bat_priv = netdev_priv(hard_iface->soft_iface);
265 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
268 /* we are in the process of shutting this interface down */
269 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE ||
270 hard_iface->if_status == BATADV_IF_TO_BE_REMOVED)
273 /* the interface was enabled but may not be ready yet */
274 if (hard_iface->if_status != BATADV_IF_ACTIVE)
277 skb = skb_copy(hard_iface->bat_v.elp_skb, GFP_ATOMIC);
281 elp_packet = (struct batadv_elp_packet *)skb->data;
282 elp_packet->seqno = htonl(atomic_read(&hard_iface->bat_v.elp_seqno));
283 elp_interval = atomic_read(&hard_iface->bat_v.elp_interval);
284 elp_packet->elp_interval = htonl(elp_interval);
286 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
287 "Sending broadcast ELP packet on interface %s, seqno %u\n",
288 hard_iface->net_dev->name,
289 atomic_read(&hard_iface->bat_v.elp_seqno));
291 batadv_send_broadcast_skb(skb, hard_iface);
293 atomic_inc(&hard_iface->bat_v.elp_seqno);
295 /* The throughput metric is updated on each sent packet. This way, if a
296 * node is dead and no longer sends packets, batman-adv is still able to
297 * react timely to its death.
299 * The throughput metric is updated by following these steps:
300 * 1) if the hard_iface is wifi => send a number of unicast ELPs for
301 * probing/sampling to each neighbor
302 * 2) update the throughput metric value of each neighbor (note that the
303 * value retrieved in this step might be 100ms old because the
304 * probing packets at point 1) could still be in the HW queue)
307 hlist_for_each_entry_rcu(hardif_neigh, &hard_iface->neigh_list, list) {
308 if (!batadv_v_elp_wifi_neigh_probe(hardif_neigh))
309 /* if something goes wrong while probing, better to stop
310 * sending packets immediately and reschedule the task
314 if (!kref_get_unless_zero(&hardif_neigh->refcount))
317 /* Reading the estimated throughput from cfg80211 is a task that
318 * may sleep and that is not allowed in an rcu protected
319 * context. Therefore schedule a task for that.
321 ret = queue_work(batadv_event_workqueue,
322 &hardif_neigh->bat_v.metric_work);
325 batadv_hardif_neigh_put(hardif_neigh);
330 batadv_v_elp_start_timer(hard_iface);
336 * batadv_v_elp_iface_enable() - setup the ELP interface private resources
337 * @hard_iface: interface for which the data has to be prepared
339 * Return: 0 on success or a -ENOMEM in case of failure.
341 int batadv_v_elp_iface_enable(struct batadv_hard_iface *hard_iface)
343 static const size_t tvlv_padding = sizeof(__be32);
344 struct batadv_elp_packet *elp_packet;
345 unsigned char *elp_buff;
350 size = ETH_HLEN + NET_IP_ALIGN + BATADV_ELP_HLEN + tvlv_padding;
351 hard_iface->bat_v.elp_skb = dev_alloc_skb(size);
352 if (!hard_iface->bat_v.elp_skb)
355 skb_reserve(hard_iface->bat_v.elp_skb, ETH_HLEN + NET_IP_ALIGN);
356 elp_buff = skb_put_zero(hard_iface->bat_v.elp_skb,
357 BATADV_ELP_HLEN + tvlv_padding);
358 elp_packet = (struct batadv_elp_packet *)elp_buff;
360 elp_packet->packet_type = BATADV_ELP;
361 elp_packet->version = BATADV_COMPAT_VERSION;
363 /* randomize initial seqno to avoid collision */
364 get_random_bytes(&random_seqno, sizeof(random_seqno));
365 atomic_set(&hard_iface->bat_v.elp_seqno, random_seqno);
367 /* assume full-duplex by default */
368 hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX;
370 /* warn the user (again) if there is no throughput data is available */
371 hard_iface->bat_v.flags &= ~BATADV_WARNING_DEFAULT;
373 if (batadv_is_wifi_hardif(hard_iface))
374 hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;
376 INIT_DELAYED_WORK(&hard_iface->bat_v.elp_wq,
377 batadv_v_elp_periodic_work);
378 batadv_v_elp_start_timer(hard_iface);
386 * batadv_v_elp_iface_disable() - release ELP interface private resources
387 * @hard_iface: interface for which the resources have to be released
389 void batadv_v_elp_iface_disable(struct batadv_hard_iface *hard_iface)
391 cancel_delayed_work_sync(&hard_iface->bat_v.elp_wq);
393 dev_kfree_skb(hard_iface->bat_v.elp_skb);
394 hard_iface->bat_v.elp_skb = NULL;
398 * batadv_v_elp_iface_activate() - update the ELP buffer belonging to the given
400 * @primary_iface: the new primary interface
401 * @hard_iface: interface holding the to-be-updated buffer
403 void batadv_v_elp_iface_activate(struct batadv_hard_iface *primary_iface,
404 struct batadv_hard_iface *hard_iface)
406 struct batadv_elp_packet *elp_packet;
409 if (!hard_iface->bat_v.elp_skb)
412 skb = hard_iface->bat_v.elp_skb;
413 elp_packet = (struct batadv_elp_packet *)skb->data;
414 ether_addr_copy(elp_packet->orig,
415 primary_iface->net_dev->dev_addr);
419 * batadv_v_elp_primary_iface_set() - change internal data to reflect the new
421 * @primary_iface: the new primary interface
423 void batadv_v_elp_primary_iface_set(struct batadv_hard_iface *primary_iface)
425 struct batadv_hard_iface *hard_iface;
427 /* update orig field of every elp iface belonging to this mesh */
429 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
430 if (primary_iface->soft_iface != hard_iface->soft_iface)
433 batadv_v_elp_iface_activate(primary_iface, hard_iface);
439 * batadv_v_elp_neigh_update() - update an ELP neighbour node
440 * @bat_priv: the bat priv with all the soft interface information
441 * @neigh_addr: the neighbour interface address
442 * @if_incoming: the interface the packet was received through
443 * @elp_packet: the received ELP packet
445 * Updates the ELP neighbour node state with the data received within the new
448 static void batadv_v_elp_neigh_update(struct batadv_priv *bat_priv,
450 struct batadv_hard_iface *if_incoming,
451 struct batadv_elp_packet *elp_packet)
454 struct batadv_neigh_node *neigh;
455 struct batadv_orig_node *orig_neigh;
456 struct batadv_hardif_neigh_node *hardif_neigh;
458 s32 elp_latest_seqno;
460 orig_neigh = batadv_v_ogm_orig_get(bat_priv, elp_packet->orig);
464 neigh = batadv_neigh_node_get_or_create(orig_neigh,
465 if_incoming, neigh_addr);
469 hardif_neigh = batadv_hardif_neigh_get(if_incoming, neigh_addr);
473 elp_latest_seqno = hardif_neigh->bat_v.elp_latest_seqno;
474 seqno_diff = ntohl(elp_packet->seqno) - elp_latest_seqno;
476 /* known or older sequence numbers are ignored. However always adopt
477 * if the router seems to have been restarted.
479 if (seqno_diff < 1 && seqno_diff > -BATADV_ELP_MAX_AGE)
482 neigh->last_seen = jiffies;
483 hardif_neigh->last_seen = jiffies;
484 hardif_neigh->bat_v.elp_latest_seqno = ntohl(elp_packet->seqno);
485 hardif_neigh->bat_v.elp_interval = ntohl(elp_packet->elp_interval);
489 batadv_hardif_neigh_put(hardif_neigh);
492 batadv_neigh_node_put(neigh);
495 batadv_orig_node_put(orig_neigh);
499 * batadv_v_elp_packet_recv() - main ELP packet handler
500 * @skb: the received packet
501 * @if_incoming: the interface this packet was received through
503 * Return: NET_RX_SUCCESS and consumes the skb if the packet was properly
504 * processed or NET_RX_DROP in case of failure.
506 int batadv_v_elp_packet_recv(struct sk_buff *skb,
507 struct batadv_hard_iface *if_incoming)
509 struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
510 struct batadv_elp_packet *elp_packet;
511 struct batadv_hard_iface *primary_if;
512 struct ethhdr *ethhdr;
514 int ret = NET_RX_DROP;
516 res = batadv_check_management_packet(skb, if_incoming, BATADV_ELP_HLEN);
520 ethhdr = eth_hdr(skb);
521 if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
524 /* did we receive a B.A.T.M.A.N. V ELP packet on an interface
525 * that does not have B.A.T.M.A.N. V ELP enabled ?
527 if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
530 elp_packet = (struct batadv_elp_packet *)skb->data;
532 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
533 "Received ELP packet from %pM seqno %u ORIG: %pM\n",
534 ethhdr->h_source, ntohl(elp_packet->seqno),
537 primary_if = batadv_primary_if_get_selected(bat_priv);
541 batadv_v_elp_neigh_update(bat_priv, ethhdr->h_source, if_incoming,
544 ret = NET_RX_SUCCESS;
545 batadv_hardif_put(primary_if);
548 if (ret == NET_RX_SUCCESS)