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Linus Luessingd6f94d92016-01-16 16:40:09 +08001/* Copyright (C) 2011-2016 B.A.T.M.A.N. contributors:
2 *
3 * Linus Lüssing, Marek Lindner
4 *
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.
8 *
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.
13 *
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/>.
16 */
17
18#include "bat_v_elp.h"
19#include "main.h"
20
21#include <linux/atomic.h>
22#include <linux/byteorder/generic.h>
23#include <linux/errno.h>
24#include <linux/etherdevice.h>
Antonio Quartullic8334842015-11-10 18:50:51 +010025#include <linux/ethtool.h>
Linus Luessingd6f94d92016-01-16 16:40:09 +080026#include <linux/fs.h>
27#include <linux/if_ether.h>
28#include <linux/jiffies.h>
29#include <linux/kernel.h>
Antonio Quartullic8334842015-11-10 18:50:51 +010030#include <linux/kref.h>
Linus Luessingd6f94d92016-01-16 16:40:09 +080031#include <linux/netdevice.h>
32#include <linux/random.h>
33#include <linux/rculist.h>
34#include <linux/rcupdate.h>
Antonio Quartullic8334842015-11-10 18:50:51 +010035#include <linux/rtnetlink.h>
Linus Luessingd6f94d92016-01-16 16:40:09 +080036#include <linux/skbuff.h>
37#include <linux/stddef.h>
38#include <linux/string.h>
39#include <linux/types.h>
40#include <linux/workqueue.h>
Antonio Quartullic8334842015-11-10 18:50:51 +010041#include <net/cfg80211.h>
Linus Luessingd6f94d92016-01-16 16:40:09 +080042
43#include "bat_algo.h"
Antonio Quartulli93231582016-01-16 16:40:13 +080044#include "bat_v_ogm.h"
Linus Luessingd6f94d92016-01-16 16:40:09 +080045#include "hard-interface.h"
Linus Luessing162bd642016-01-16 16:40:10 +080046#include "originator.h"
Linus Luessingd6f94d92016-01-16 16:40:09 +080047#include "packet.h"
Linus Luessing162bd642016-01-16 16:40:10 +080048#include "routing.h"
Linus Luessingd6f94d92016-01-16 16:40:09 +080049#include "send.h"
50
51/**
52 * batadv_v_elp_start_timer - restart timer for ELP periodic work
53 * @hard_iface: the interface for which the timer has to be reset
54 */
55static void batadv_v_elp_start_timer(struct batadv_hard_iface *hard_iface)
56{
57 unsigned int msecs;
58
59 msecs = atomic_read(&hard_iface->bat_v.elp_interval) - BATADV_JITTER;
60 msecs += prandom_u32() % (2 * BATADV_JITTER);
61
62 queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.elp_wq,
63 msecs_to_jiffies(msecs));
64}
65
66/**
Antonio Quartullic8334842015-11-10 18:50:51 +010067 * batadv_v_elp_get_throughput - get the throughput towards a neighbour
68 * @neigh: the neighbour for which the throughput has to be obtained
69 *
70 * Return: The throughput towards the given neighbour in multiples of 100kpbs
71 * (a value of '1' equals to 0.1Mbps, '10' equals 1Mbps, etc).
72 */
73static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh)
74{
75 struct batadv_hard_iface *hard_iface = neigh->if_incoming;
76 struct ethtool_link_ksettings link_settings;
77 struct station_info sinfo;
78 u32 throughput;
79 int ret;
80
81 /* if the user specified a customised value for this interface, then
82 * return it directly
83 */
84 throughput = atomic_read(&hard_iface->bat_v.throughput_override);
85 if (throughput != 0)
86 return throughput;
87
88 /* if this is a wireless device, then ask its throughput through
89 * cfg80211 API
90 */
91 if (batadv_is_wifi_netdev(hard_iface->net_dev)) {
92 if (hard_iface->net_dev->ieee80211_ptr) {
93 ret = cfg80211_get_station(hard_iface->net_dev,
94 neigh->addr, &sinfo);
95 if (ret == -ENOENT) {
96 /* Node is not associated anymore! It would be
97 * possible to delete this neighbor. For now set
98 * the throughput metric to 0.
99 */
100 return 0;
101 }
102 if (!ret)
103 return sinfo.expected_throughput / 100;
104 }
105
106 /* unsupported WiFi driver version */
107 goto default_throughput;
108 }
109
110 /* if not a wifi interface, check if this device provides data via
111 * ethtool (e.g. an Ethernet adapter)
112 */
113 memset(&link_settings, 0, sizeof(link_settings));
114 rtnl_lock();
115 ret = __ethtool_get_link_ksettings(hard_iface->net_dev, &link_settings);
116 rtnl_unlock();
117 if (ret == 0) {
118 /* link characteristics might change over time */
119 if (link_settings.base.duplex == DUPLEX_FULL)
120 hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX;
121 else
122 hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;
123
124 throughput = link_settings.base.speed;
125 if (throughput && (throughput != SPEED_UNKNOWN))
126 return throughput * 10;
127 }
128
129default_throughput:
130 if (!(hard_iface->bat_v.flags & BATADV_WARNING_DEFAULT)) {
131 batadv_info(hard_iface->soft_iface,
132 "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",
133 hard_iface->net_dev->name,
134 BATADV_THROUGHPUT_DEFAULT_VALUE / 10,
135 BATADV_THROUGHPUT_DEFAULT_VALUE % 10);
136 hard_iface->bat_v.flags |= BATADV_WARNING_DEFAULT;
137 }
138
139 /* if none of the above cases apply, return the base_throughput */
140 return BATADV_THROUGHPUT_DEFAULT_VALUE;
141}
142
143/**
144 * batadv_v_elp_throughput_metric_update - worker updating the throughput metric
145 * of a single hop neighbour
146 * @work: the work queue item
147 */
148void batadv_v_elp_throughput_metric_update(struct work_struct *work)
149{
150 struct batadv_hardif_neigh_node_bat_v *neigh_bat_v;
151 struct batadv_hardif_neigh_node *neigh;
152
153 neigh_bat_v = container_of(work, struct batadv_hardif_neigh_node_bat_v,
154 metric_work);
155 neigh = container_of(neigh_bat_v, struct batadv_hardif_neigh_node,
156 bat_v);
157
158 ewma_throughput_add(&neigh->bat_v.throughput,
159 batadv_v_elp_get_throughput(neigh));
160
161 /* decrement refcounter to balance increment performed before scheduling
162 * this task
163 */
164 batadv_hardif_neigh_put(neigh);
165}
166
167/**
Antonio Quartulli8d2d4992015-11-10 18:51:22 +0100168 * batadv_v_elp_wifi_neigh_probe - send link probing packets to a neighbour
169 * @neigh: the neighbour to probe
170 *
171 * Sends a predefined number of unicast wifi packets to a given neighbour in
172 * order to trigger the throughput estimation on this link by the RC algorithm.
173 * Packets are sent only if there there is not enough payload unicast traffic
174 * towards this neighbour..
175 *
176 * Return: True on success and false in case of error during skb preparation.
177 */
178static bool
179batadv_v_elp_wifi_neigh_probe(struct batadv_hardif_neigh_node *neigh)
180{
181 struct batadv_hard_iface *hard_iface = neigh->if_incoming;
182 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
183 unsigned long last_tx_diff;
184 struct sk_buff *skb;
185 int probe_len, i;
186 int elp_skb_len;
187
188 /* this probing routine is for Wifi neighbours only */
189 if (!batadv_is_wifi_netdev(hard_iface->net_dev))
190 return true;
191
192 /* probe the neighbor only if no unicast packets have been sent
193 * to it in the last 100 milliseconds: this is the rate control
194 * algorithm sampling interval (minstrel). In this way, if not
195 * enough traffic has been sent to the neighbor, batman-adv can
196 * generate 2 probe packets and push the RC algorithm to perform
197 * the sampling
198 */
199 last_tx_diff = jiffies_to_msecs(jiffies - neigh->bat_v.last_unicast_tx);
200 if (last_tx_diff <= BATADV_ELP_PROBE_MAX_TX_DIFF)
201 return true;
202
203 probe_len = max_t(int, sizeof(struct batadv_elp_packet),
204 BATADV_ELP_MIN_PROBE_SIZE);
205
206 for (i = 0; i < BATADV_ELP_PROBES_PER_NODE; i++) {
207 elp_skb_len = hard_iface->bat_v.elp_skb->len;
208 skb = skb_copy_expand(hard_iface->bat_v.elp_skb, 0,
209 probe_len - elp_skb_len,
210 GFP_ATOMIC);
211 if (!skb)
212 return false;
213
214 /* Tell the skb to get as big as the allocated space (we want
215 * the packet to be exactly of that size to make the link
216 * throughput estimation effective.
217 */
218 skb_put(skb, probe_len - hard_iface->bat_v.elp_skb->len);
219
220 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
221 "Sending unicast (probe) ELP packet on interface %s to %pM\n",
222 hard_iface->net_dev->name, neigh->addr);
223
224 batadv_send_skb_packet(skb, hard_iface, neigh->addr);
225 }
226
227 return true;
228}
229
230/**
Linus Luessingd6f94d92016-01-16 16:40:09 +0800231 * batadv_v_elp_periodic_work - ELP periodic task per interface
232 * @work: work queue item
233 *
234 * Emits broadcast ELP message in regular intervals.
235 */
236static void batadv_v_elp_periodic_work(struct work_struct *work)
237{
Antonio Quartullic8334842015-11-10 18:50:51 +0100238 struct batadv_hardif_neigh_node *hardif_neigh;
Linus Luessingd6f94d92016-01-16 16:40:09 +0800239 struct batadv_hard_iface *hard_iface;
240 struct batadv_hard_iface_bat_v *bat_v;
241 struct batadv_elp_packet *elp_packet;
242 struct batadv_priv *bat_priv;
243 struct sk_buff *skb;
244 u32 elp_interval;
245
246 bat_v = container_of(work, struct batadv_hard_iface_bat_v, elp_wq.work);
247 hard_iface = container_of(bat_v, struct batadv_hard_iface, bat_v);
248 bat_priv = netdev_priv(hard_iface->soft_iface);
249
250 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
251 goto out;
252
253 /* we are in the process of shutting this interface down */
254 if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) ||
255 (hard_iface->if_status == BATADV_IF_TO_BE_REMOVED))
256 goto out;
257
258 /* the interface was enabled but may not be ready yet */
259 if (hard_iface->if_status != BATADV_IF_ACTIVE)
260 goto restart_timer;
261
262 skb = skb_copy(hard_iface->bat_v.elp_skb, GFP_ATOMIC);
263 if (!skb)
264 goto restart_timer;
265
266 elp_packet = (struct batadv_elp_packet *)skb->data;
267 elp_packet->seqno = htonl(atomic_read(&hard_iface->bat_v.elp_seqno));
268 elp_interval = atomic_read(&hard_iface->bat_v.elp_interval);
269 elp_packet->elp_interval = htonl(elp_interval);
270
271 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
272 "Sending broadcast ELP packet on interface %s, seqno %u\n",
273 hard_iface->net_dev->name,
274 atomic_read(&hard_iface->bat_v.elp_seqno));
275
Antonio Quartulli95d39272016-01-16 16:40:15 +0800276 batadv_send_broadcast_skb(skb, hard_iface);
Linus Luessingd6f94d92016-01-16 16:40:09 +0800277
278 atomic_inc(&hard_iface->bat_v.elp_seqno);
279
Antonio Quartullic8334842015-11-10 18:50:51 +0100280 /* The throughput metric is updated on each sent packet. This way, if a
281 * node is dead and no longer sends packets, batman-adv is still able to
282 * react timely to its death.
283 *
284 * The throughput metric is updated by following these steps:
285 * 1) if the hard_iface is wifi => send a number of unicast ELPs for
286 * probing/sampling to each neighbor
287 * 2) update the throughput metric value of each neighbor (note that the
288 * value retrieved in this step might be 100ms old because the
289 * probing packets at point 1) could still be in the HW queue)
290 */
291 rcu_read_lock();
292 hlist_for_each_entry_rcu(hardif_neigh, &hard_iface->neigh_list, list) {
Antonio Quartulli8d2d4992015-11-10 18:51:22 +0100293 if (!batadv_v_elp_wifi_neigh_probe(hardif_neigh))
294 /* if something goes wrong while probing, better to stop
295 * sending packets immediately and reschedule the task
296 */
297 break;
298
Antonio Quartullic8334842015-11-10 18:50:51 +0100299 if (!kref_get_unless_zero(&hardif_neigh->refcount))
300 continue;
301
302 /* Reading the estimated throughput from cfg80211 is a task that
303 * may sleep and that is not allowed in an rcu protected
304 * context. Therefore schedule a task for that.
305 */
306 queue_work(batadv_event_workqueue,
307 &hardif_neigh->bat_v.metric_work);
308 }
309 rcu_read_unlock();
310
Linus Luessingd6f94d92016-01-16 16:40:09 +0800311restart_timer:
312 batadv_v_elp_start_timer(hard_iface);
313out:
314 return;
315}
316
317/**
318 * batadv_v_elp_iface_enable - setup the ELP interface private resources
319 * @hard_iface: interface for which the data has to be prepared
320 *
321 * Return: 0 on success or a -ENOMEM in case of failure.
322 */
323int batadv_v_elp_iface_enable(struct batadv_hard_iface *hard_iface)
324{
325 struct batadv_elp_packet *elp_packet;
326 unsigned char *elp_buff;
327 u32 random_seqno;
328 size_t size;
329 int res = -ENOMEM;
330
331 size = ETH_HLEN + NET_IP_ALIGN + BATADV_ELP_HLEN;
332 hard_iface->bat_v.elp_skb = dev_alloc_skb(size);
333 if (!hard_iface->bat_v.elp_skb)
334 goto out;
335
336 skb_reserve(hard_iface->bat_v.elp_skb, ETH_HLEN + NET_IP_ALIGN);
337 elp_buff = skb_push(hard_iface->bat_v.elp_skb, BATADV_ELP_HLEN);
338 elp_packet = (struct batadv_elp_packet *)elp_buff;
339 memset(elp_packet, 0, BATADV_ELP_HLEN);
340
341 elp_packet->packet_type = BATADV_ELP;
342 elp_packet->version = BATADV_COMPAT_VERSION;
343
344 /* randomize initial seqno to avoid collision */
345 get_random_bytes(&random_seqno, sizeof(random_seqno));
346 atomic_set(&hard_iface->bat_v.elp_seqno, random_seqno);
347 atomic_set(&hard_iface->bat_v.elp_interval, 500);
348
Antonio Quartullic8334842015-11-10 18:50:51 +0100349 /* assume full-duplex by default */
350 hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX;
351
352 /* warn the user (again) if there is no throughput data is available */
353 hard_iface->bat_v.flags &= ~BATADV_WARNING_DEFAULT;
354
355 if (batadv_is_wifi_netdev(hard_iface->net_dev))
356 hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;
357
Linus Luessingd6f94d92016-01-16 16:40:09 +0800358 INIT_DELAYED_WORK(&hard_iface->bat_v.elp_wq,
359 batadv_v_elp_periodic_work);
360 batadv_v_elp_start_timer(hard_iface);
361 res = 0;
362
363out:
364 return res;
365}
366
367/**
368 * batadv_v_elp_iface_disable - release ELP interface private resources
369 * @hard_iface: interface for which the resources have to be released
370 */
371void batadv_v_elp_iface_disable(struct batadv_hard_iface *hard_iface)
372{
373 cancel_delayed_work_sync(&hard_iface->bat_v.elp_wq);
374
375 dev_kfree_skb(hard_iface->bat_v.elp_skb);
376 hard_iface->bat_v.elp_skb = NULL;
377}
378
379/**
380 * batadv_v_elp_primary_iface_set - change internal data to reflect the new
381 * primary interface
382 * @primary_iface: the new primary interface
383 */
384void batadv_v_elp_primary_iface_set(struct batadv_hard_iface *primary_iface)
385{
386 struct batadv_hard_iface *hard_iface;
387 struct batadv_elp_packet *elp_packet;
388 struct sk_buff *skb;
389
390 /* update orig field of every elp iface belonging to this mesh */
391 rcu_read_lock();
392 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
393 if (primary_iface->soft_iface != hard_iface->soft_iface)
394 continue;
395
396 if (!hard_iface->bat_v.elp_skb)
397 continue;
398
399 skb = hard_iface->bat_v.elp_skb;
400 elp_packet = (struct batadv_elp_packet *)skb->data;
401 ether_addr_copy(elp_packet->orig,
402 primary_iface->net_dev->dev_addr);
403 }
404 rcu_read_unlock();
405}
Linus Luessing162bd642016-01-16 16:40:10 +0800406
407/**
Linus Luessing162bd642016-01-16 16:40:10 +0800408 * batadv_v_elp_neigh_update - update an ELP neighbour node
409 * @bat_priv: the bat priv with all the soft interface information
410 * @neigh_addr: the neighbour interface address
411 * @if_incoming: the interface the packet was received through
412 * @elp_packet: the received ELP packet
413 *
414 * Updates the ELP neighbour node state with the data received within the new
415 * ELP packet.
416 */
417static void batadv_v_elp_neigh_update(struct batadv_priv *bat_priv,
418 u8 *neigh_addr,
419 struct batadv_hard_iface *if_incoming,
420 struct batadv_elp_packet *elp_packet)
421
422{
423 struct batadv_neigh_node *neigh;
424 struct batadv_orig_node *orig_neigh;
425 struct batadv_hardif_neigh_node *hardif_neigh;
426 s32 seqno_diff;
427 s32 elp_latest_seqno;
428
429 orig_neigh = batadv_v_ogm_orig_get(bat_priv, elp_packet->orig);
430 if (!orig_neigh)
431 return;
432
433 neigh = batadv_neigh_node_new(orig_neigh, if_incoming, neigh_addr);
434 if (!neigh)
435 goto orig_free;
436
437 hardif_neigh = batadv_hardif_neigh_get(if_incoming, neigh_addr);
438 if (!hardif_neigh)
439 goto neigh_free;
440
441 elp_latest_seqno = hardif_neigh->bat_v.elp_latest_seqno;
442 seqno_diff = ntohl(elp_packet->seqno) - elp_latest_seqno;
443
444 /* known or older sequence numbers are ignored. However always adopt
445 * if the router seems to have been restarted.
446 */
447 if (seqno_diff < 1 && seqno_diff > -BATADV_ELP_MAX_AGE)
448 goto hardif_free;
449
450 neigh->last_seen = jiffies;
451 hardif_neigh->last_seen = jiffies;
452 hardif_neigh->bat_v.elp_latest_seqno = ntohl(elp_packet->seqno);
453 hardif_neigh->bat_v.elp_interval = ntohl(elp_packet->elp_interval);
454
455hardif_free:
456 if (hardif_neigh)
457 batadv_hardif_neigh_put(hardif_neigh);
458neigh_free:
459 if (neigh)
460 batadv_neigh_node_put(neigh);
461orig_free:
462 if (orig_neigh)
463 batadv_orig_node_put(orig_neigh);
464}
465
466/**
467 * batadv_v_elp_packet_recv - main ELP packet handler
468 * @skb: the received packet
469 * @if_incoming: the interface this packet was received through
470 *
471 * Return: NET_RX_SUCCESS and consumes the skb if the packet was peoperly
472 * processed or NET_RX_DROP in case of failure.
473 */
474int batadv_v_elp_packet_recv(struct sk_buff *skb,
475 struct batadv_hard_iface *if_incoming)
476{
477 struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
478 struct batadv_elp_packet *elp_packet;
479 struct batadv_hard_iface *primary_if;
480 struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
481 bool ret;
482
483 ret = batadv_check_management_packet(skb, if_incoming, BATADV_ELP_HLEN);
484 if (!ret)
485 return NET_RX_DROP;
486
487 if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
488 return NET_RX_DROP;
489
490 /* did we receive a B.A.T.M.A.N. V ELP packet on an interface
491 * that does not have B.A.T.M.A.N. V ELP enabled ?
492 */
493 if (strcmp(bat_priv->bat_algo_ops->name, "BATMAN_V") != 0)
494 return NET_RX_DROP;
495
496 elp_packet = (struct batadv_elp_packet *)skb->data;
497
498 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
499 "Received ELP packet from %pM seqno %u ORIG: %pM\n",
500 ethhdr->h_source, ntohl(elp_packet->seqno),
501 elp_packet->orig);
502
503 primary_if = batadv_primary_if_get_selected(bat_priv);
504 if (!primary_if)
505 goto out;
506
507 batadv_v_elp_neigh_update(bat_priv, ethhdr->h_source, if_incoming,
508 elp_packet);
509
510out:
511 if (primary_if)
512 batadv_hardif_put(primary_if);
513 consume_skb(skb);
514 return NET_RX_SUCCESS;
515}