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[linux/fpc-iii.git] / net / batman-adv / bat_v_elp.c
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1 /* Copyright (C) 2011-2017 B.A.T.M.A.N. contributors:
3 * Linus Lüssing, Marek Lindner
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of version 2 of the GNU General Public
7 * License as published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, see <http://www.gnu.org/licenses/>.
18 #include "bat_v_elp.h"
19 #include "main.h"
21 #include <linux/atomic.h>
22 #include <linux/bitops.h>
23 #include <linux/byteorder/generic.h>
24 #include <linux/errno.h>
25 #include <linux/etherdevice.h>
26 #include <linux/ethtool.h>
27 #include <linux/fs.h>
28 #include <linux/if_ether.h>
29 #include <linux/jiffies.h>
30 #include <linux/kernel.h>
31 #include <linux/kref.h>
32 #include <linux/netdevice.h>
33 #include <linux/nl80211.h>
34 #include <linux/random.h>
35 #include <linux/rculist.h>
36 #include <linux/rcupdate.h>
37 #include <linux/rtnetlink.h>
38 #include <linux/skbuff.h>
39 #include <linux/stddef.h>
40 #include <linux/string.h>
41 #include <linux/types.h>
42 #include <linux/workqueue.h>
43 #include <net/cfg80211.h>
45 #include "bat_algo.h"
46 #include "bat_v_ogm.h"
47 #include "hard-interface.h"
48 #include "log.h"
49 #include "originator.h"
50 #include "packet.h"
51 #include "routing.h"
52 #include "send.h"
54 /**
55 * batadv_v_elp_start_timer - restart timer for ELP periodic work
56 * @hard_iface: the interface for which the timer has to be reset
58 static void batadv_v_elp_start_timer(struct batadv_hard_iface *hard_iface)
60 unsigned int msecs;
62 msecs = atomic_read(&hard_iface->bat_v.elp_interval) - BATADV_JITTER;
63 msecs += prandom_u32() % (2 * BATADV_JITTER);
65 queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.elp_wq,
66 msecs_to_jiffies(msecs));
69 /**
70 * batadv_v_elp_get_throughput - get the throughput towards a neighbour
71 * @neigh: the neighbour for which the throughput has to be obtained
73 * Return: The throughput towards the given neighbour in multiples of 100kpbs
74 * (a value of '1' equals to 0.1Mbps, '10' equals 1Mbps, etc).
76 static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh)
78 struct batadv_hard_iface *hard_iface = neigh->if_incoming;
79 struct ethtool_link_ksettings link_settings;
80 struct net_device *real_netdev;
81 struct station_info sinfo;
82 u32 throughput;
83 int ret;
85 /* if the user specified a customised value for this interface, then
86 * return it directly
88 throughput = atomic_read(&hard_iface->bat_v.throughput_override);
89 if (throughput != 0)
90 return throughput;
92 /* if this is a wireless device, then ask its throughput through
93 * cfg80211 API
95 if (batadv_is_wifi_hardif(hard_iface)) {
96 if (!batadv_is_cfg80211_hardif(hard_iface))
97 /* unsupported WiFi driver version */
98 goto default_throughput;
100 real_netdev = batadv_get_real_netdev(hard_iface->net_dev);
101 if (!real_netdev)
102 goto default_throughput;
104 ret = cfg80211_get_station(real_netdev, neigh->addr, &sinfo);
106 dev_put(real_netdev);
107 if (ret == -ENOENT) {
108 /* Node is not associated anymore! It would be
109 * possible to delete this neighbor. For now set
110 * the throughput metric to 0.
112 return 0;
114 if (ret)
115 goto default_throughput;
116 if (!(sinfo.filled & BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT)))
117 goto default_throughput;
119 return sinfo.expected_throughput / 100;
122 /* if not a wifi interface, check if this device provides data via
123 * ethtool (e.g. an Ethernet adapter)
125 memset(&link_settings, 0, sizeof(link_settings));
126 rtnl_lock();
127 ret = __ethtool_get_link_ksettings(hard_iface->net_dev, &link_settings);
128 rtnl_unlock();
129 if (ret == 0) {
130 /* link characteristics might change over time */
131 if (link_settings.base.duplex == DUPLEX_FULL)
132 hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX;
133 else
134 hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;
136 throughput = link_settings.base.speed;
137 if (throughput && (throughput != SPEED_UNKNOWN))
138 return throughput * 10;
141 default_throughput:
142 if (!(hard_iface->bat_v.flags & BATADV_WARNING_DEFAULT)) {
143 batadv_info(hard_iface->soft_iface,
144 "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",
145 hard_iface->net_dev->name,
146 BATADV_THROUGHPUT_DEFAULT_VALUE / 10,
147 BATADV_THROUGHPUT_DEFAULT_VALUE % 10);
148 hard_iface->bat_v.flags |= BATADV_WARNING_DEFAULT;
151 /* if none of the above cases apply, return the base_throughput */
152 return BATADV_THROUGHPUT_DEFAULT_VALUE;
156 * batadv_v_elp_throughput_metric_update - worker updating the throughput metric
157 * of a single hop neighbour
158 * @work: the work queue item
160 void batadv_v_elp_throughput_metric_update(struct work_struct *work)
162 struct batadv_hardif_neigh_node_bat_v *neigh_bat_v;
163 struct batadv_hardif_neigh_node *neigh;
165 neigh_bat_v = container_of(work, struct batadv_hardif_neigh_node_bat_v,
166 metric_work);
167 neigh = container_of(neigh_bat_v, struct batadv_hardif_neigh_node,
168 bat_v);
170 ewma_throughput_add(&neigh->bat_v.throughput,
171 batadv_v_elp_get_throughput(neigh));
173 /* decrement refcounter to balance increment performed before scheduling
174 * this task
176 batadv_hardif_neigh_put(neigh);
180 * batadv_v_elp_wifi_neigh_probe - send link probing packets to a neighbour
181 * @neigh: the neighbour to probe
183 * Sends a predefined number of unicast wifi packets to a given neighbour in
184 * order to trigger the throughput estimation on this link by the RC algorithm.
185 * Packets are sent only if there there is not enough payload unicast traffic
186 * towards this neighbour..
188 * Return: True on success and false in case of error during skb preparation.
190 static bool
191 batadv_v_elp_wifi_neigh_probe(struct batadv_hardif_neigh_node *neigh)
193 struct batadv_hard_iface *hard_iface = neigh->if_incoming;
194 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
195 unsigned long last_tx_diff;
196 struct sk_buff *skb;
197 int probe_len, i;
198 int elp_skb_len;
200 /* this probing routine is for Wifi neighbours only */
201 if (!batadv_is_wifi_hardif(hard_iface))
202 return true;
204 /* probe the neighbor only if no unicast packets have been sent
205 * to it in the last 100 milliseconds: this is the rate control
206 * algorithm sampling interval (minstrel). In this way, if not
207 * enough traffic has been sent to the neighbor, batman-adv can
208 * generate 2 probe packets and push the RC algorithm to perform
209 * the sampling
211 last_tx_diff = jiffies_to_msecs(jiffies - neigh->bat_v.last_unicast_tx);
212 if (last_tx_diff <= BATADV_ELP_PROBE_MAX_TX_DIFF)
213 return true;
215 probe_len = max_t(int, sizeof(struct batadv_elp_packet),
216 BATADV_ELP_MIN_PROBE_SIZE);
218 for (i = 0; i < BATADV_ELP_PROBES_PER_NODE; i++) {
219 elp_skb_len = hard_iface->bat_v.elp_skb->len;
220 skb = skb_copy_expand(hard_iface->bat_v.elp_skb, 0,
221 probe_len - elp_skb_len,
222 GFP_ATOMIC);
223 if (!skb)
224 return false;
226 /* Tell the skb to get as big as the allocated space (we want
227 * the packet to be exactly of that size to make the link
228 * throughput estimation effective.
230 skb_put(skb, probe_len - hard_iface->bat_v.elp_skb->len);
232 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
233 "Sending unicast (probe) ELP packet on interface %s to %pM\n",
234 hard_iface->net_dev->name, neigh->addr);
236 batadv_send_skb_packet(skb, hard_iface, neigh->addr);
239 return true;
243 * batadv_v_elp_periodic_work - ELP periodic task per interface
244 * @work: work queue item
246 * Emits broadcast ELP message in regular intervals.
248 static void batadv_v_elp_periodic_work(struct work_struct *work)
250 struct batadv_hardif_neigh_node *hardif_neigh;
251 struct batadv_hard_iface *hard_iface;
252 struct batadv_hard_iface_bat_v *bat_v;
253 struct batadv_elp_packet *elp_packet;
254 struct batadv_priv *bat_priv;
255 struct sk_buff *skb;
256 u32 elp_interval;
258 bat_v = container_of(work, struct batadv_hard_iface_bat_v, elp_wq.work);
259 hard_iface = container_of(bat_v, struct batadv_hard_iface, bat_v);
260 bat_priv = netdev_priv(hard_iface->soft_iface);
262 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
263 goto out;
265 /* we are in the process of shutting this interface down */
266 if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) ||
267 (hard_iface->if_status == BATADV_IF_TO_BE_REMOVED))
268 goto out;
270 /* the interface was enabled but may not be ready yet */
271 if (hard_iface->if_status != BATADV_IF_ACTIVE)
272 goto restart_timer;
274 skb = skb_copy(hard_iface->bat_v.elp_skb, GFP_ATOMIC);
275 if (!skb)
276 goto restart_timer;
278 elp_packet = (struct batadv_elp_packet *)skb->data;
279 elp_packet->seqno = htonl(atomic_read(&hard_iface->bat_v.elp_seqno));
280 elp_interval = atomic_read(&hard_iface->bat_v.elp_interval);
281 elp_packet->elp_interval = htonl(elp_interval);
283 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
284 "Sending broadcast ELP packet on interface %s, seqno %u\n",
285 hard_iface->net_dev->name,
286 atomic_read(&hard_iface->bat_v.elp_seqno));
288 batadv_send_broadcast_skb(skb, hard_iface);
290 atomic_inc(&hard_iface->bat_v.elp_seqno);
292 /* The throughput metric is updated on each sent packet. This way, if a
293 * node is dead and no longer sends packets, batman-adv is still able to
294 * react timely to its death.
296 * The throughput metric is updated by following these steps:
297 * 1) if the hard_iface is wifi => send a number of unicast ELPs for
298 * probing/sampling to each neighbor
299 * 2) update the throughput metric value of each neighbor (note that the
300 * value retrieved in this step might be 100ms old because the
301 * probing packets at point 1) could still be in the HW queue)
303 rcu_read_lock();
304 hlist_for_each_entry_rcu(hardif_neigh, &hard_iface->neigh_list, list) {
305 if (!batadv_v_elp_wifi_neigh_probe(hardif_neigh))
306 /* if something goes wrong while probing, better to stop
307 * sending packets immediately and reschedule the task
309 break;
311 if (!kref_get_unless_zero(&hardif_neigh->refcount))
312 continue;
314 /* Reading the estimated throughput from cfg80211 is a task that
315 * may sleep and that is not allowed in an rcu protected
316 * context. Therefore schedule a task for that.
318 queue_work(batadv_event_workqueue,
319 &hardif_neigh->bat_v.metric_work);
321 rcu_read_unlock();
323 restart_timer:
324 batadv_v_elp_start_timer(hard_iface);
325 out:
326 return;
330 * batadv_v_elp_iface_enable - setup the ELP interface private resources
331 * @hard_iface: interface for which the data has to be prepared
333 * Return: 0 on success or a -ENOMEM in case of failure.
335 int batadv_v_elp_iface_enable(struct batadv_hard_iface *hard_iface)
337 struct batadv_elp_packet *elp_packet;
338 unsigned char *elp_buff;
339 u32 random_seqno;
340 size_t size;
341 int res = -ENOMEM;
343 size = ETH_HLEN + NET_IP_ALIGN + BATADV_ELP_HLEN;
344 hard_iface->bat_v.elp_skb = dev_alloc_skb(size);
345 if (!hard_iface->bat_v.elp_skb)
346 goto out;
348 skb_reserve(hard_iface->bat_v.elp_skb, ETH_HLEN + NET_IP_ALIGN);
349 elp_buff = skb_put_zero(hard_iface->bat_v.elp_skb, BATADV_ELP_HLEN);
350 elp_packet = (struct batadv_elp_packet *)elp_buff;
352 elp_packet->packet_type = BATADV_ELP;
353 elp_packet->version = BATADV_COMPAT_VERSION;
355 /* randomize initial seqno to avoid collision */
356 get_random_bytes(&random_seqno, sizeof(random_seqno));
357 atomic_set(&hard_iface->bat_v.elp_seqno, random_seqno);
359 /* assume full-duplex by default */
360 hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX;
362 /* warn the user (again) if there is no throughput data is available */
363 hard_iface->bat_v.flags &= ~BATADV_WARNING_DEFAULT;
365 if (batadv_is_wifi_hardif(hard_iface))
366 hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;
368 INIT_DELAYED_WORK(&hard_iface->bat_v.elp_wq,
369 batadv_v_elp_periodic_work);
370 batadv_v_elp_start_timer(hard_iface);
371 res = 0;
373 out:
374 return res;
378 * batadv_v_elp_iface_disable - release ELP interface private resources
379 * @hard_iface: interface for which the resources have to be released
381 void batadv_v_elp_iface_disable(struct batadv_hard_iface *hard_iface)
383 cancel_delayed_work_sync(&hard_iface->bat_v.elp_wq);
385 dev_kfree_skb(hard_iface->bat_v.elp_skb);
386 hard_iface->bat_v.elp_skb = NULL;
390 * batadv_v_elp_iface_activate - update the ELP buffer belonging to the given
391 * hard-interface
392 * @primary_iface: the new primary interface
393 * @hard_iface: interface holding the to-be-updated buffer
395 void batadv_v_elp_iface_activate(struct batadv_hard_iface *primary_iface,
396 struct batadv_hard_iface *hard_iface)
398 struct batadv_elp_packet *elp_packet;
399 struct sk_buff *skb;
401 if (!hard_iface->bat_v.elp_skb)
402 return;
404 skb = hard_iface->bat_v.elp_skb;
405 elp_packet = (struct batadv_elp_packet *)skb->data;
406 ether_addr_copy(elp_packet->orig,
407 primary_iface->net_dev->dev_addr);
411 * batadv_v_elp_primary_iface_set - change internal data to reflect the new
412 * primary interface
413 * @primary_iface: the new primary interface
415 void batadv_v_elp_primary_iface_set(struct batadv_hard_iface *primary_iface)
417 struct batadv_hard_iface *hard_iface;
419 /* update orig field of every elp iface belonging to this mesh */
420 rcu_read_lock();
421 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
422 if (primary_iface->soft_iface != hard_iface->soft_iface)
423 continue;
425 batadv_v_elp_iface_activate(primary_iface, hard_iface);
427 rcu_read_unlock();
431 * batadv_v_elp_neigh_update - update an ELP neighbour node
432 * @bat_priv: the bat priv with all the soft interface information
433 * @neigh_addr: the neighbour interface address
434 * @if_incoming: the interface the packet was received through
435 * @elp_packet: the received ELP packet
437 * Updates the ELP neighbour node state with the data received within the new
438 * ELP packet.
440 static void batadv_v_elp_neigh_update(struct batadv_priv *bat_priv,
441 u8 *neigh_addr,
442 struct batadv_hard_iface *if_incoming,
443 struct batadv_elp_packet *elp_packet)
446 struct batadv_neigh_node *neigh;
447 struct batadv_orig_node *orig_neigh;
448 struct batadv_hardif_neigh_node *hardif_neigh;
449 s32 seqno_diff;
450 s32 elp_latest_seqno;
452 orig_neigh = batadv_v_ogm_orig_get(bat_priv, elp_packet->orig);
453 if (!orig_neigh)
454 return;
456 neigh = batadv_neigh_node_get_or_create(orig_neigh,
457 if_incoming, neigh_addr);
458 if (!neigh)
459 goto orig_free;
461 hardif_neigh = batadv_hardif_neigh_get(if_incoming, neigh_addr);
462 if (!hardif_neigh)
463 goto neigh_free;
465 elp_latest_seqno = hardif_neigh->bat_v.elp_latest_seqno;
466 seqno_diff = ntohl(elp_packet->seqno) - elp_latest_seqno;
468 /* known or older sequence numbers are ignored. However always adopt
469 * if the router seems to have been restarted.
471 if (seqno_diff < 1 && seqno_diff > -BATADV_ELP_MAX_AGE)
472 goto hardif_free;
474 neigh->last_seen = jiffies;
475 hardif_neigh->last_seen = jiffies;
476 hardif_neigh->bat_v.elp_latest_seqno = ntohl(elp_packet->seqno);
477 hardif_neigh->bat_v.elp_interval = ntohl(elp_packet->elp_interval);
479 hardif_free:
480 if (hardif_neigh)
481 batadv_hardif_neigh_put(hardif_neigh);
482 neigh_free:
483 if (neigh)
484 batadv_neigh_node_put(neigh);
485 orig_free:
486 if (orig_neigh)
487 batadv_orig_node_put(orig_neigh);
491 * batadv_v_elp_packet_recv - main ELP packet handler
492 * @skb: the received packet
493 * @if_incoming: the interface this packet was received through
495 * Return: NET_RX_SUCCESS and consumes the skb if the packet was peoperly
496 * processed or NET_RX_DROP in case of failure.
498 int batadv_v_elp_packet_recv(struct sk_buff *skb,
499 struct batadv_hard_iface *if_incoming)
501 struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
502 struct batadv_elp_packet *elp_packet;
503 struct batadv_hard_iface *primary_if;
504 struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
505 bool res;
506 int ret = NET_RX_DROP;
508 res = batadv_check_management_packet(skb, if_incoming, BATADV_ELP_HLEN);
509 if (!res)
510 goto free_skb;
512 if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
513 goto free_skb;
515 /* did we receive a B.A.T.M.A.N. V ELP packet on an interface
516 * that does not have B.A.T.M.A.N. V ELP enabled ?
518 if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
519 goto free_skb;
521 elp_packet = (struct batadv_elp_packet *)skb->data;
523 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
524 "Received ELP packet from %pM seqno %u ORIG: %pM\n",
525 ethhdr->h_source, ntohl(elp_packet->seqno),
526 elp_packet->orig);
528 primary_if = batadv_primary_if_get_selected(bat_priv);
529 if (!primary_if)
530 goto free_skb;
532 batadv_v_elp_neigh_update(bat_priv, ethhdr->h_source, if_incoming,
533 elp_packet);
535 ret = NET_RX_SUCCESS;
536 batadv_hardif_put(primary_if);
538 free_skb:
539 if (ret == NET_RX_SUCCESS)
540 consume_skb(skb);
541 else
542 kfree_skb(skb);
544 return ret;