1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 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/minmax.h>
22 #include <linux/netdevice.h>
23 #include <linux/nl80211.h>
24 #include <linux/prandom.h>
25 #include <linux/random.h>
26 #include <linux/rculist.h>
27 #include <linux/rcupdate.h>
28 #include <linux/rtnetlink.h>
29 #include <linux/skbuff.h>
30 #include <linux/stddef.h>
31 #include <linux/string.h>
32 #include <linux/types.h>
33 #include <linux/workqueue.h>
34 #include <net/cfg80211.h>
35 #include <uapi/linux/batadv_packet.h>
38 #include "bat_v_ogm.h"
39 #include "hard-interface.h"
41 #include "originator.h"
46 * batadv_v_elp_start_timer() - restart timer for ELP periodic work
47 * @hard_iface: the interface for which the timer has to be reset
49 static void batadv_v_elp_start_timer(struct batadv_hard_iface
*hard_iface
)
53 msecs
= atomic_read(&hard_iface
->bat_v
.elp_interval
) - BATADV_JITTER
;
54 msecs
+= prandom_u32_max(2 * BATADV_JITTER
);
56 queue_delayed_work(batadv_event_workqueue
, &hard_iface
->bat_v
.elp_wq
,
57 msecs_to_jiffies(msecs
));
61 * batadv_v_elp_get_throughput() - get the throughput towards a neighbour
62 * @neigh: the neighbour for which the throughput has to be obtained
64 * Return: The throughput towards the given neighbour in multiples of 100kpbs
65 * (a value of '1' equals 0.1Mbps, '10' equals 1Mbps, etc).
67 static u32
batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node
*neigh
)
69 struct batadv_hard_iface
*hard_iface
= neigh
->if_incoming
;
70 struct ethtool_link_ksettings link_settings
;
71 struct net_device
*real_netdev
;
72 struct station_info sinfo
;
76 /* if the user specified a customised value for this interface, then
79 throughput
= atomic_read(&hard_iface
->bat_v
.throughput_override
);
83 /* if this is a wireless device, then ask its throughput through
86 if (batadv_is_wifi_hardif(hard_iface
)) {
87 if (!batadv_is_cfg80211_hardif(hard_iface
))
88 /* unsupported WiFi driver version */
89 goto default_throughput
;
91 real_netdev
= batadv_get_real_netdev(hard_iface
->net_dev
);
93 goto default_throughput
;
95 ret
= cfg80211_get_station(real_netdev
, neigh
->addr
, &sinfo
);
98 /* free the TID stats immediately */
99 cfg80211_sinfo_release_content(&sinfo
);
102 dev_put(real_netdev
);
103 if (ret
== -ENOENT
) {
104 /* Node is not associated anymore! It would be
105 * possible to delete this neighbor. For now set
106 * the throughput metric to 0.
111 goto default_throughput
;
113 if (sinfo
.filled
& BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT
))
114 return sinfo
.expected_throughput
/ 100;
116 /* try to estimate the expected throughput based on reported tx
119 if (sinfo
.filled
& BIT(NL80211_STA_INFO_TX_BITRATE
))
120 return cfg80211_calculate_bitrate(&sinfo
.txrate
) / 3;
122 goto default_throughput
;
125 /* if not a wifi interface, check if this device provides data via
126 * ethtool (e.g. an Ethernet adapter)
128 memset(&link_settings
, 0, sizeof(link_settings
));
130 ret
= __ethtool_get_link_ksettings(hard_iface
->net_dev
, &link_settings
);
133 /* link characteristics might change over time */
134 if (link_settings
.base
.duplex
== DUPLEX_FULL
)
135 hard_iface
->bat_v
.flags
|= BATADV_FULL_DUPLEX
;
137 hard_iface
->bat_v
.flags
&= ~BATADV_FULL_DUPLEX
;
139 throughput
= link_settings
.base
.speed
;
140 if (throughput
&& throughput
!= SPEED_UNKNOWN
)
141 return throughput
* 10;
145 if (!(hard_iface
->bat_v
.flags
& BATADV_WARNING_DEFAULT
)) {
146 batadv_info(hard_iface
->soft_iface
,
147 "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",
148 hard_iface
->net_dev
->name
,
149 BATADV_THROUGHPUT_DEFAULT_VALUE
/ 10,
150 BATADV_THROUGHPUT_DEFAULT_VALUE
% 10);
151 hard_iface
->bat_v
.flags
|= BATADV_WARNING_DEFAULT
;
154 /* if none of the above cases apply, return the base_throughput */
155 return BATADV_THROUGHPUT_DEFAULT_VALUE
;
159 * batadv_v_elp_throughput_metric_update() - worker updating the throughput
160 * metric of a single hop neighbour
161 * @work: the work queue item
163 void batadv_v_elp_throughput_metric_update(struct work_struct
*work
)
165 struct batadv_hardif_neigh_node_bat_v
*neigh_bat_v
;
166 struct batadv_hardif_neigh_node
*neigh
;
168 neigh_bat_v
= container_of(work
, struct batadv_hardif_neigh_node_bat_v
,
170 neigh
= container_of(neigh_bat_v
, struct batadv_hardif_neigh_node
,
173 ewma_throughput_add(&neigh
->bat_v
.throughput
,
174 batadv_v_elp_get_throughput(neigh
));
176 /* decrement refcounter to balance increment performed before scheduling
179 batadv_hardif_neigh_put(neigh
);
183 * batadv_v_elp_wifi_neigh_probe() - send link probing packets to a neighbour
184 * @neigh: the neighbour to probe
186 * Sends a predefined number of unicast wifi packets to a given neighbour in
187 * order to trigger the throughput estimation on this link by the RC algorithm.
188 * Packets are sent only if there is not enough payload unicast traffic towards
191 * Return: True on success and false in case of error during skb preparation.
194 batadv_v_elp_wifi_neigh_probe(struct batadv_hardif_neigh_node
*neigh
)
196 struct batadv_hard_iface
*hard_iface
= neigh
->if_incoming
;
197 struct batadv_priv
*bat_priv
= netdev_priv(hard_iface
->soft_iface
);
198 unsigned long last_tx_diff
;
203 /* this probing routine is for Wifi neighbours only */
204 if (!batadv_is_wifi_hardif(hard_iface
))
207 /* probe the neighbor only if no unicast packets have been sent
208 * to it in the last 100 milliseconds: this is the rate control
209 * algorithm sampling interval (minstrel). In this way, if not
210 * enough traffic has been sent to the neighbor, batman-adv can
211 * generate 2 probe packets and push the RC algorithm to perform
214 last_tx_diff
= jiffies_to_msecs(jiffies
- neigh
->bat_v
.last_unicast_tx
);
215 if (last_tx_diff
<= BATADV_ELP_PROBE_MAX_TX_DIFF
)
218 probe_len
= max_t(int, sizeof(struct batadv_elp_packet
),
219 BATADV_ELP_MIN_PROBE_SIZE
);
221 for (i
= 0; i
< BATADV_ELP_PROBES_PER_NODE
; i
++) {
222 elp_skb_len
= hard_iface
->bat_v
.elp_skb
->len
;
223 skb
= skb_copy_expand(hard_iface
->bat_v
.elp_skb
, 0,
224 probe_len
- elp_skb_len
,
229 /* Tell the skb to get as big as the allocated space (we want
230 * the packet to be exactly of that size to make the link
231 * throughput estimation effective.
233 skb_put_zero(skb
, probe_len
- hard_iface
->bat_v
.elp_skb
->len
);
235 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
236 "Sending unicast (probe) ELP packet on interface %s to %pM\n",
237 hard_iface
->net_dev
->name
, neigh
->addr
);
239 batadv_send_skb_packet(skb
, hard_iface
, neigh
->addr
);
246 * batadv_v_elp_periodic_work() - ELP periodic task per interface
247 * @work: work queue item
249 * Emits broadcast ELP messages in regular intervals.
251 static void batadv_v_elp_periodic_work(struct work_struct
*work
)
253 struct batadv_hardif_neigh_node
*hardif_neigh
;
254 struct batadv_hard_iface
*hard_iface
;
255 struct batadv_hard_iface_bat_v
*bat_v
;
256 struct batadv_elp_packet
*elp_packet
;
257 struct batadv_priv
*bat_priv
;
262 bat_v
= container_of(work
, struct batadv_hard_iface_bat_v
, elp_wq
.work
);
263 hard_iface
= container_of(bat_v
, struct batadv_hard_iface
, bat_v
);
264 bat_priv
= netdev_priv(hard_iface
->soft_iface
);
266 if (atomic_read(&bat_priv
->mesh_state
) == BATADV_MESH_DEACTIVATING
)
269 /* we are in the process of shutting this interface down */
270 if (hard_iface
->if_status
== BATADV_IF_NOT_IN_USE
||
271 hard_iface
->if_status
== BATADV_IF_TO_BE_REMOVED
)
274 /* the interface was enabled but may not be ready yet */
275 if (hard_iface
->if_status
!= BATADV_IF_ACTIVE
)
278 skb
= skb_copy(hard_iface
->bat_v
.elp_skb
, GFP_ATOMIC
);
282 elp_packet
= (struct batadv_elp_packet
*)skb
->data
;
283 elp_packet
->seqno
= htonl(atomic_read(&hard_iface
->bat_v
.elp_seqno
));
284 elp_interval
= atomic_read(&hard_iface
->bat_v
.elp_interval
);
285 elp_packet
->elp_interval
= htonl(elp_interval
);
287 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
288 "Sending broadcast ELP packet on interface %s, seqno %u\n",
289 hard_iface
->net_dev
->name
,
290 atomic_read(&hard_iface
->bat_v
.elp_seqno
));
292 batadv_send_broadcast_skb(skb
, hard_iface
);
294 atomic_inc(&hard_iface
->bat_v
.elp_seqno
);
296 /* The throughput metric is updated on each sent packet. This way, if a
297 * node is dead and no longer sends packets, batman-adv is still able to
298 * react timely to its death.
300 * The throughput metric is updated by following these steps:
301 * 1) if the hard_iface is wifi => send a number of unicast ELPs for
302 * probing/sampling to each neighbor
303 * 2) update the throughput metric value of each neighbor (note that the
304 * value retrieved in this step might be 100ms old because the
305 * probing packets at point 1) could still be in the HW queue)
308 hlist_for_each_entry_rcu(hardif_neigh
, &hard_iface
->neigh_list
, list
) {
309 if (!batadv_v_elp_wifi_neigh_probe(hardif_neigh
))
310 /* if something goes wrong while probing, better to stop
311 * sending packets immediately and reschedule the task
315 if (!kref_get_unless_zero(&hardif_neigh
->refcount
))
318 /* Reading the estimated throughput from cfg80211 is a task that
319 * may sleep and that is not allowed in an rcu protected
320 * context. Therefore schedule a task for that.
322 ret
= queue_work(batadv_event_workqueue
,
323 &hardif_neigh
->bat_v
.metric_work
);
326 batadv_hardif_neigh_put(hardif_neigh
);
331 batadv_v_elp_start_timer(hard_iface
);
337 * batadv_v_elp_iface_enable() - setup the ELP interface private resources
338 * @hard_iface: interface for which the data has to be prepared
340 * Return: 0 on success or a -ENOMEM in case of failure.
342 int batadv_v_elp_iface_enable(struct batadv_hard_iface
*hard_iface
)
344 static const size_t tvlv_padding
= sizeof(__be32
);
345 struct batadv_elp_packet
*elp_packet
;
346 unsigned char *elp_buff
;
351 size
= ETH_HLEN
+ NET_IP_ALIGN
+ BATADV_ELP_HLEN
+ tvlv_padding
;
352 hard_iface
->bat_v
.elp_skb
= dev_alloc_skb(size
);
353 if (!hard_iface
->bat_v
.elp_skb
)
356 skb_reserve(hard_iface
->bat_v
.elp_skb
, ETH_HLEN
+ NET_IP_ALIGN
);
357 elp_buff
= skb_put_zero(hard_iface
->bat_v
.elp_skb
,
358 BATADV_ELP_HLEN
+ tvlv_padding
);
359 elp_packet
= (struct batadv_elp_packet
*)elp_buff
;
361 elp_packet
->packet_type
= BATADV_ELP
;
362 elp_packet
->version
= BATADV_COMPAT_VERSION
;
364 /* randomize initial seqno to avoid collision */
365 get_random_bytes(&random_seqno
, sizeof(random_seqno
));
366 atomic_set(&hard_iface
->bat_v
.elp_seqno
, random_seqno
);
368 /* assume full-duplex by default */
369 hard_iface
->bat_v
.flags
|= BATADV_FULL_DUPLEX
;
371 /* warn the user (again) if there is no throughput data is available */
372 hard_iface
->bat_v
.flags
&= ~BATADV_WARNING_DEFAULT
;
374 if (batadv_is_wifi_hardif(hard_iface
))
375 hard_iface
->bat_v
.flags
&= ~BATADV_FULL_DUPLEX
;
377 INIT_DELAYED_WORK(&hard_iface
->bat_v
.elp_wq
,
378 batadv_v_elp_periodic_work
);
379 batadv_v_elp_start_timer(hard_iface
);
387 * batadv_v_elp_iface_disable() - release ELP interface private resources
388 * @hard_iface: interface for which the resources have to be released
390 void batadv_v_elp_iface_disable(struct batadv_hard_iface
*hard_iface
)
392 cancel_delayed_work_sync(&hard_iface
->bat_v
.elp_wq
);
394 dev_kfree_skb(hard_iface
->bat_v
.elp_skb
);
395 hard_iface
->bat_v
.elp_skb
= NULL
;
399 * batadv_v_elp_iface_activate() - update the ELP buffer belonging to the given
401 * @primary_iface: the new primary interface
402 * @hard_iface: interface holding the to-be-updated buffer
404 void batadv_v_elp_iface_activate(struct batadv_hard_iface
*primary_iface
,
405 struct batadv_hard_iface
*hard_iface
)
407 struct batadv_elp_packet
*elp_packet
;
410 if (!hard_iface
->bat_v
.elp_skb
)
413 skb
= hard_iface
->bat_v
.elp_skb
;
414 elp_packet
= (struct batadv_elp_packet
*)skb
->data
;
415 ether_addr_copy(elp_packet
->orig
,
416 primary_iface
->net_dev
->dev_addr
);
420 * batadv_v_elp_primary_iface_set() - change internal data to reflect the new
422 * @primary_iface: the new primary interface
424 void batadv_v_elp_primary_iface_set(struct batadv_hard_iface
*primary_iface
)
426 struct batadv_hard_iface
*hard_iface
;
428 /* update orig field of every elp iface belonging to this mesh */
430 list_for_each_entry_rcu(hard_iface
, &batadv_hardif_list
, list
) {
431 if (primary_iface
->soft_iface
!= hard_iface
->soft_iface
)
434 batadv_v_elp_iface_activate(primary_iface
, hard_iface
);
440 * batadv_v_elp_neigh_update() - update an ELP neighbour node
441 * @bat_priv: the bat priv with all the soft interface information
442 * @neigh_addr: the neighbour interface address
443 * @if_incoming: the interface the packet was received through
444 * @elp_packet: the received ELP packet
446 * Updates the ELP neighbour node state with the data received within the new
449 static void batadv_v_elp_neigh_update(struct batadv_priv
*bat_priv
,
451 struct batadv_hard_iface
*if_incoming
,
452 struct batadv_elp_packet
*elp_packet
)
455 struct batadv_neigh_node
*neigh
;
456 struct batadv_orig_node
*orig_neigh
;
457 struct batadv_hardif_neigh_node
*hardif_neigh
;
459 s32 elp_latest_seqno
;
461 orig_neigh
= batadv_v_ogm_orig_get(bat_priv
, elp_packet
->orig
);
465 neigh
= batadv_neigh_node_get_or_create(orig_neigh
,
466 if_incoming
, neigh_addr
);
470 hardif_neigh
= batadv_hardif_neigh_get(if_incoming
, neigh_addr
);
474 elp_latest_seqno
= hardif_neigh
->bat_v
.elp_latest_seqno
;
475 seqno_diff
= ntohl(elp_packet
->seqno
) - elp_latest_seqno
;
477 /* known or older sequence numbers are ignored. However always adopt
478 * if the router seems to have been restarted.
480 if (seqno_diff
< 1 && seqno_diff
> -BATADV_ELP_MAX_AGE
)
483 neigh
->last_seen
= jiffies
;
484 hardif_neigh
->last_seen
= jiffies
;
485 hardif_neigh
->bat_v
.elp_latest_seqno
= ntohl(elp_packet
->seqno
);
486 hardif_neigh
->bat_v
.elp_interval
= ntohl(elp_packet
->elp_interval
);
489 batadv_hardif_neigh_put(hardif_neigh
);
491 batadv_neigh_node_put(neigh
);
493 batadv_orig_node_put(orig_neigh
);
497 * batadv_v_elp_packet_recv() - main ELP packet handler
498 * @skb: the received packet
499 * @if_incoming: the interface this packet was received through
501 * Return: NET_RX_SUCCESS and consumes the skb if the packet was properly
502 * processed or NET_RX_DROP in case of failure.
504 int batadv_v_elp_packet_recv(struct sk_buff
*skb
,
505 struct batadv_hard_iface
*if_incoming
)
507 struct batadv_priv
*bat_priv
= netdev_priv(if_incoming
->soft_iface
);
508 struct batadv_elp_packet
*elp_packet
;
509 struct batadv_hard_iface
*primary_if
;
510 struct ethhdr
*ethhdr
= (struct ethhdr
*)skb_mac_header(skb
);
512 int ret
= NET_RX_DROP
;
514 res
= batadv_check_management_packet(skb
, if_incoming
, BATADV_ELP_HLEN
);
518 if (batadv_is_my_mac(bat_priv
, ethhdr
->h_source
))
521 /* did we receive a B.A.T.M.A.N. V ELP packet on an interface
522 * that does not have B.A.T.M.A.N. V ELP enabled ?
524 if (strcmp(bat_priv
->algo_ops
->name
, "BATMAN_V") != 0)
527 elp_packet
= (struct batadv_elp_packet
*)skb
->data
;
529 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
530 "Received ELP packet from %pM seqno %u ORIG: %pM\n",
531 ethhdr
->h_source
, ntohl(elp_packet
->seqno
),
534 primary_if
= batadv_primary_if_get_selected(bat_priv
);
538 batadv_v_elp_neigh_update(bat_priv
, ethhdr
->h_source
, if_incoming
,
541 ret
= NET_RX_SUCCESS
;
542 batadv_hardif_put(primary_if
);
545 if (ret
== NET_RX_SUCCESS
)