1 /* Copyright (C) 2011-2016 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"
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>
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>
46 #include "bat_v_ogm.h"
47 #include "hard-interface.h"
49 #include "originator.h"
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)
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));
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 station_info sinfo;
84 /* if the user specified a customised value for this interface, then
87 throughput = atomic_read(&hard_iface->bat_v.throughput_override);
91 /* if this is a wireless device, then ask its throughput through
94 if (batadv_is_wifi_netdev(hard_iface->net_dev)) {
95 if (hard_iface->net_dev->ieee80211_ptr) {
96 ret = cfg80211_get_station(hard_iface->net_dev,
99 /* Node is not associated anymore! It would be
100 * possible to delete this neighbor. For now set
101 * the throughput metric to 0.
106 goto default_throughput;
107 if (!(sinfo.filled & BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT)))
108 goto default_throughput;
110 return sinfo.expected_throughput / 100;
113 /* unsupported WiFi driver version */
114 goto default_throughput;
117 /* if not a wifi interface, check if this device provides data via
118 * ethtool (e.g. an Ethernet adapter)
120 memset(&link_settings, 0, sizeof(link_settings));
122 ret = __ethtool_get_link_ksettings(hard_iface->net_dev, &link_settings);
125 /* link characteristics might change over time */
126 if (link_settings.base.duplex == DUPLEX_FULL)
127 hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX;
129 hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;
131 throughput = link_settings.base.speed;
132 if (throughput && (throughput != SPEED_UNKNOWN))
133 return throughput * 10;
137 if (!(hard_iface->bat_v.flags & BATADV_WARNING_DEFAULT)) {
138 batadv_info(hard_iface->soft_iface,
139 "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",
140 hard_iface->net_dev->name,
141 BATADV_THROUGHPUT_DEFAULT_VALUE / 10,
142 BATADV_THROUGHPUT_DEFAULT_VALUE % 10);
143 hard_iface->bat_v.flags |= BATADV_WARNING_DEFAULT;
146 /* if none of the above cases apply, return the base_throughput */
147 return BATADV_THROUGHPUT_DEFAULT_VALUE;
151 * batadv_v_elp_throughput_metric_update - worker updating the throughput metric
152 * of a single hop neighbour
153 * @work: the work queue item
155 void batadv_v_elp_throughput_metric_update(struct work_struct *work)
157 struct batadv_hardif_neigh_node_bat_v *neigh_bat_v;
158 struct batadv_hardif_neigh_node *neigh;
160 neigh_bat_v = container_of(work, struct batadv_hardif_neigh_node_bat_v,
162 neigh = container_of(neigh_bat_v, struct batadv_hardif_neigh_node,
165 ewma_throughput_add(&neigh->bat_v.throughput,
166 batadv_v_elp_get_throughput(neigh));
168 /* decrement refcounter to balance increment performed before scheduling
171 batadv_hardif_neigh_put(neigh);
175 * batadv_v_elp_wifi_neigh_probe - send link probing packets to a neighbour
176 * @neigh: the neighbour to probe
178 * Sends a predefined number of unicast wifi packets to a given neighbour in
179 * order to trigger the throughput estimation on this link by the RC algorithm.
180 * Packets are sent only if there there is not enough payload unicast traffic
181 * towards this neighbour..
183 * Return: True on success and false in case of error during skb preparation.
186 batadv_v_elp_wifi_neigh_probe(struct batadv_hardif_neigh_node *neigh)
188 struct batadv_hard_iface *hard_iface = neigh->if_incoming;
189 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
190 unsigned long last_tx_diff;
196 /* this probing routine is for Wifi neighbours only */
197 if (!batadv_is_wifi_netdev(hard_iface->net_dev))
200 /* probe the neighbor only if no unicast packets have been sent
201 * to it in the last 100 milliseconds: this is the rate control
202 * algorithm sampling interval (minstrel). In this way, if not
203 * enough traffic has been sent to the neighbor, batman-adv can
204 * generate 2 probe packets and push the RC algorithm to perform
207 last_tx_diff = jiffies_to_msecs(jiffies - neigh->bat_v.last_unicast_tx);
208 if (last_tx_diff <= BATADV_ELP_PROBE_MAX_TX_DIFF)
211 probe_len = max_t(int, sizeof(struct batadv_elp_packet),
212 BATADV_ELP_MIN_PROBE_SIZE);
214 for (i = 0; i < BATADV_ELP_PROBES_PER_NODE; i++) {
215 elp_skb_len = hard_iface->bat_v.elp_skb->len;
216 skb = skb_copy_expand(hard_iface->bat_v.elp_skb, 0,
217 probe_len - elp_skb_len,
222 /* Tell the skb to get as big as the allocated space (we want
223 * the packet to be exactly of that size to make the link
224 * throughput estimation effective.
226 tmp = skb_put(skb, probe_len - hard_iface->bat_v.elp_skb->len);
227 memset(tmp, 0, probe_len - hard_iface->bat_v.elp_skb->len);
229 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
230 "Sending unicast (probe) ELP packet on interface %s to %pM\n",
231 hard_iface->net_dev->name, neigh->addr);
233 batadv_send_skb_packet(skb, hard_iface, neigh->addr);
240 * batadv_v_elp_periodic_work - ELP periodic task per interface
241 * @work: work queue item
243 * Emits broadcast ELP message in regular intervals.
245 static void batadv_v_elp_periodic_work(struct work_struct *work)
247 struct batadv_hardif_neigh_node *hardif_neigh;
248 struct batadv_hard_iface *hard_iface;
249 struct batadv_hard_iface_bat_v *bat_v;
250 struct batadv_elp_packet *elp_packet;
251 struct batadv_priv *bat_priv;
256 bat_v = container_of(work, struct batadv_hard_iface_bat_v, elp_wq.work);
257 hard_iface = container_of(bat_v, struct batadv_hard_iface, bat_v);
258 bat_priv = netdev_priv(hard_iface->soft_iface);
260 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
263 /* we are in the process of shutting this interface down */
264 if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) ||
265 (hard_iface->if_status == BATADV_IF_TO_BE_REMOVED))
268 /* the interface was enabled but may not be ready yet */
269 if (hard_iface->if_status != BATADV_IF_ACTIVE)
272 skb = skb_copy(hard_iface->bat_v.elp_skb, GFP_ATOMIC);
276 elp_packet = (struct batadv_elp_packet *)skb->data;
277 elp_packet->seqno = htonl(atomic_read(&hard_iface->bat_v.elp_seqno));
278 elp_interval = atomic_read(&hard_iface->bat_v.elp_interval);
279 elp_packet->elp_interval = htonl(elp_interval);
281 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
282 "Sending broadcast ELP packet on interface %s, seqno %u\n",
283 hard_iface->net_dev->name,
284 atomic_read(&hard_iface->bat_v.elp_seqno));
286 batadv_send_broadcast_skb(skb, hard_iface);
288 atomic_inc(&hard_iface->bat_v.elp_seqno);
290 /* The throughput metric is updated on each sent packet. This way, if a
291 * node is dead and no longer sends packets, batman-adv is still able to
292 * react timely to its death.
294 * The throughput metric is updated by following these steps:
295 * 1) if the hard_iface is wifi => send a number of unicast ELPs for
296 * probing/sampling to each neighbor
297 * 2) update the throughput metric value of each neighbor (note that the
298 * value retrieved in this step might be 100ms old because the
299 * probing packets at point 1) could still be in the HW queue)
302 hlist_for_each_entry_rcu(hardif_neigh, &hard_iface->neigh_list, list) {
303 if (!batadv_v_elp_wifi_neigh_probe(hardif_neigh))
304 /* if something goes wrong while probing, better to stop
305 * sending packets immediately and reschedule the task
309 if (!kref_get_unless_zero(&hardif_neigh->refcount))
312 /* Reading the estimated throughput from cfg80211 is a task that
313 * may sleep and that is not allowed in an rcu protected
314 * context. Therefore schedule a task for that.
316 ret = queue_work(batadv_event_workqueue,
317 &hardif_neigh->bat_v.metric_work);
320 batadv_hardif_neigh_put(hardif_neigh);
325 batadv_v_elp_start_timer(hard_iface);
331 * batadv_v_elp_iface_enable - setup the ELP interface private resources
332 * @hard_iface: interface for which the data has to be prepared
334 * Return: 0 on success or a -ENOMEM in case of failure.
336 int batadv_v_elp_iface_enable(struct batadv_hard_iface *hard_iface)
338 static const size_t tvlv_padding = sizeof(__be32);
339 struct batadv_elp_packet *elp_packet;
340 unsigned char *elp_buff;
345 size = ETH_HLEN + NET_IP_ALIGN + BATADV_ELP_HLEN + tvlv_padding;
346 hard_iface->bat_v.elp_skb = dev_alloc_skb(size);
347 if (!hard_iface->bat_v.elp_skb)
350 skb_reserve(hard_iface->bat_v.elp_skb, ETH_HLEN + NET_IP_ALIGN);
351 elp_buff = skb_put(hard_iface->bat_v.elp_skb,
352 BATADV_ELP_HLEN + tvlv_padding);
353 elp_packet = (struct batadv_elp_packet *)elp_buff;
354 memset(elp_packet, 0, BATADV_ELP_HLEN + tvlv_padding);
356 elp_packet->packet_type = BATADV_ELP;
357 elp_packet->version = BATADV_COMPAT_VERSION;
359 /* randomize initial seqno to avoid collision */
360 get_random_bytes(&random_seqno, sizeof(random_seqno));
361 atomic_set(&hard_iface->bat_v.elp_seqno, random_seqno);
363 /* assume full-duplex by default */
364 hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX;
366 /* warn the user (again) if there is no throughput data is available */
367 hard_iface->bat_v.flags &= ~BATADV_WARNING_DEFAULT;
369 if (batadv_is_wifi_netdev(hard_iface->net_dev))
370 hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;
372 INIT_DELAYED_WORK(&hard_iface->bat_v.elp_wq,
373 batadv_v_elp_periodic_work);
374 batadv_v_elp_start_timer(hard_iface);
382 * batadv_v_elp_iface_disable - release ELP interface private resources
383 * @hard_iface: interface for which the resources have to be released
385 void batadv_v_elp_iface_disable(struct batadv_hard_iface *hard_iface)
387 cancel_delayed_work_sync(&hard_iface->bat_v.elp_wq);
389 dev_kfree_skb(hard_iface->bat_v.elp_skb);
390 hard_iface->bat_v.elp_skb = NULL;
394 * batadv_v_elp_iface_activate - update the ELP buffer belonging to the given
396 * @primary_iface: the new primary interface
397 * @hard_iface: interface holding the to-be-updated buffer
399 void batadv_v_elp_iface_activate(struct batadv_hard_iface *primary_iface,
400 struct batadv_hard_iface *hard_iface)
402 struct batadv_elp_packet *elp_packet;
405 if (!hard_iface->bat_v.elp_skb)
408 skb = hard_iface->bat_v.elp_skb;
409 elp_packet = (struct batadv_elp_packet *)skb->data;
410 ether_addr_copy(elp_packet->orig,
411 primary_iface->net_dev->dev_addr);
415 * batadv_v_elp_primary_iface_set - change internal data to reflect the new
417 * @primary_iface: the new primary interface
419 void batadv_v_elp_primary_iface_set(struct batadv_hard_iface *primary_iface)
421 struct batadv_hard_iface *hard_iface;
423 /* update orig field of every elp iface belonging to this mesh */
425 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
426 if (primary_iface->soft_iface != hard_iface->soft_iface)
429 batadv_v_elp_iface_activate(primary_iface, hard_iface);
435 * batadv_v_elp_neigh_update - update an ELP neighbour node
436 * @bat_priv: the bat priv with all the soft interface information
437 * @neigh_addr: the neighbour interface address
438 * @if_incoming: the interface the packet was received through
439 * @elp_packet: the received ELP packet
441 * Updates the ELP neighbour node state with the data received within the new
444 static void batadv_v_elp_neigh_update(struct batadv_priv *bat_priv,
446 struct batadv_hard_iface *if_incoming,
447 struct batadv_elp_packet *elp_packet)
450 struct batadv_neigh_node *neigh;
451 struct batadv_orig_node *orig_neigh;
452 struct batadv_hardif_neigh_node *hardif_neigh;
454 s32 elp_latest_seqno;
456 orig_neigh = batadv_v_ogm_orig_get(bat_priv, elp_packet->orig);
460 neigh = batadv_neigh_node_get_or_create(orig_neigh,
461 if_incoming, neigh_addr);
465 hardif_neigh = batadv_hardif_neigh_get(if_incoming, neigh_addr);
469 elp_latest_seqno = hardif_neigh->bat_v.elp_latest_seqno;
470 seqno_diff = ntohl(elp_packet->seqno) - elp_latest_seqno;
472 /* known or older sequence numbers are ignored. However always adopt
473 * if the router seems to have been restarted.
475 if (seqno_diff < 1 && seqno_diff > -BATADV_ELP_MAX_AGE)
478 neigh->last_seen = jiffies;
479 hardif_neigh->last_seen = jiffies;
480 hardif_neigh->bat_v.elp_latest_seqno = ntohl(elp_packet->seqno);
481 hardif_neigh->bat_v.elp_interval = ntohl(elp_packet->elp_interval);
485 batadv_hardif_neigh_put(hardif_neigh);
488 batadv_neigh_node_put(neigh);
491 batadv_orig_node_put(orig_neigh);
495 * batadv_v_elp_packet_recv - main ELP packet handler
496 * @skb: the received packet
497 * @if_incoming: the interface this packet was received through
499 * Return: NET_RX_SUCCESS and consumes the skb if the packet was peoperly
500 * processed or NET_RX_DROP in case of failure.
502 int batadv_v_elp_packet_recv(struct sk_buff *skb,
503 struct batadv_hard_iface *if_incoming)
505 struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
506 struct batadv_elp_packet *elp_packet;
507 struct batadv_hard_iface *primary_if;
508 struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
511 ret = batadv_check_management_packet(skb, if_incoming, BATADV_ELP_HLEN);
515 if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
518 /* did we receive a B.A.T.M.A.N. V ELP packet on an interface
519 * that does not have B.A.T.M.A.N. V ELP enabled ?
521 if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
524 elp_packet = (struct batadv_elp_packet *)skb->data;
526 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
527 "Received ELP packet from %pM seqno %u ORIG: %pM\n",
528 ethhdr->h_source, ntohl(elp_packet->seqno),
531 primary_if = batadv_primary_if_get_selected(bat_priv);
535 batadv_v_elp_neigh_update(bat_priv, ethhdr->h_source, if_incoming,
540 batadv_hardif_put(primary_if);
542 return NET_RX_SUCCESS;