2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License.
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9 * GNU General Public License for more details.
11 * You should have received a copy of the GNU General Public License
12 * along with this program; if not, write to the Free Software
13 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
15 * Copyright (C) 2020 embedd.ch
16 * Copyright (C) 2020 Felix Fietkau <nbd@nbd.name>
17 * Copyright (C) 2020 John Crispin <john@phrozen.org>
25 below_assoc_threshold(struct sta_info
*si_cur
, struct sta_info
*si_new
)
27 int n_assoc_cur
= si_cur
->node
->n_assoc
;
28 int n_assoc_new
= si_new
->node
->n_assoc
;
29 bool ref_5g
= si_cur
->node
->freq
> 4000;
30 bool node_5g
= si_new
->node
->freq
> 4000;
32 if (ref_5g
&& !node_5g
)
33 n_assoc_new
+= config
.band_steering_threshold
;
34 else if (!ref_5g
&& node_5g
)
35 n_assoc_cur
+= config
.band_steering_threshold
;
37 n_assoc_new
+= config
.load_balancing_threshold
;
39 return n_assoc_new
<= n_assoc_cur
;
43 better_signal_strength(struct sta_info
*si_cur
, struct sta_info
*si_new
)
45 const bool is_better
= si_new
->signal
- si_cur
->signal
46 > (int) config
.signal_diff_threshold
;
48 if (!config
.signal_diff_threshold
)
55 below_load_threshold(struct sta_info
*si
)
57 return si
->node
->n_assoc
>= config
.load_kick_min_clients
&&
58 si
->node
->load
> config
.load_kick_threshold
;
62 has_better_load(struct sta_info
*si_cur
, struct sta_info
*si_new
)
64 return !below_load_threshold(si_cur
) && below_load_threshold(si_new
);
68 below_max_assoc(struct sta_info
*si
)
70 struct usteer_node
*node
= si
->node
;
72 return !node
->max_assoc
|| node
->n_assoc
< node
->max_assoc
;
76 is_better_candidate(struct sta_info
*si_cur
, struct sta_info
*si_new
)
80 if (!below_max_assoc(si_new
))
83 if (below_assoc_threshold(si_cur
, si_new
) &&
84 !below_assoc_threshold(si_new
, si_cur
))
85 reasons
|= (1 << UEV_SELECT_REASON_NUM_ASSOC
);
87 if (better_signal_strength(si_cur
, si_new
))
88 reasons
|= (1 << UEV_SELECT_REASON_SIGNAL
);
90 if (has_better_load(si_cur
, si_new
) &&
91 !has_better_load(si_cur
, si_new
))
92 reasons
|= (1 << UEV_SELECT_REASON_LOAD
);
97 static struct sta_info
*
98 find_better_candidate(struct sta_info
*si_ref
, struct uevent
*ev
)
101 struct sta
*sta
= si_ref
->sta
;
104 list_for_each_entry(si
, &sta
->nodes
, list
) {
108 if (current_time
- si
->seen
> config
.seen_policy_timeout
)
111 if (strcmp(si
->node
->ssid
, si_ref
->node
->ssid
) != 0)
114 reasons
= is_better_candidate(si_ref
, si
);
118 if (is_better_candidate(si
, si_ref
))
123 ev
->select_reasons
= reasons
;
133 snr_to_signal(struct usteer_node
*node
, int snr
)
147 usteer_check_request(struct sta_info
*si
, enum usteer_event_type type
)
155 if (type
== EVENT_TYPE_AUTH
)
158 if (type
== EVENT_TYPE_ASSOC
) {
159 /* Check if assoc request has lower signal than min_signal.
160 * If this is the case, block assoc even when assoc steering is enabled.
162 * Otherwise, the client potentially ends up in a assoc - kick loop.
164 if (config
.min_snr
&& si
->signal
< snr_to_signal(si
->node
, config
.min_snr
)) {
165 ev
.reason
= UEV_REASON_LOW_SIGNAL
;
166 ev
.threshold
.cur
= si
->signal
;
167 ev
.threshold
.ref
= snr_to_signal(si
->node
, config
.min_snr
);
170 } else if (!config
.assoc_steering
) {
175 min_signal
= snr_to_signal(si
->node
, config
.min_connect_snr
);
176 if (si
->signal
< min_signal
) {
177 ev
.reason
= UEV_REASON_LOW_SIGNAL
;
178 ev
.threshold
.cur
= si
->signal
;
179 ev
.threshold
.ref
= min_signal
;
184 if (current_time
- si
->created
< config
.initial_connect_delay
) {
185 ev
.reason
= UEV_REASON_CONNECT_DELAY
;
186 ev
.threshold
.cur
= current_time
- si
->created
;
187 ev
.threshold
.ref
= config
.initial_connect_delay
;
192 if (!find_better_candidate(si
, &ev
))
195 ev
.reason
= UEV_REASON_BETTER_CANDIDATE
;
196 ev
.node_cur
= si
->node
;
201 case EVENT_TYPE_PROBE
:
202 ev
.type
= UEV_PROBE_REQ_ACCEPT
;
204 case EVENT_TYPE_ASSOC
:
205 ev
.type
= UEV_ASSOC_REQ_ACCEPT
;
207 case EVENT_TYPE_AUTH
:
208 ev
.type
= UEV_AUTH_REQ_ACCEPT
;
217 if (!ret
&& si
->stats
[type
].blocked_cur
>= config
.max_retry_band
) {
218 ev
.reason
= UEV_REASON_RETRY_EXCEEDED
;
219 ev
.threshold
.cur
= si
->stats
[type
].blocked_cur
;
220 ev
.threshold
.ref
= config
.max_retry_band
;
228 is_more_kickable(struct sta_info
*si_cur
, struct sta_info
*si_new
)
233 if (si_new
->kick_count
> si_cur
->kick_count
)
236 return si_cur
->signal
> si_new
->signal
;
240 usteer_roam_set_state(struct sta_info
*si
, enum roam_trigger_state state
,
243 si
->roam_event
= current_time
;
245 if (si
->roam_state
== state
) {
246 if (si
->roam_state
== ROAM_TRIGGER_IDLE
) {
256 si
->roam_state
= state
;
261 usteer_roam_trigger_sm(struct sta_info
*si
)
268 min_signal
= snr_to_signal(si
->node
, config
.roam_trigger_snr
);
270 switch (si
->roam_state
) {
271 case ROAM_TRIGGER_SCAN
:
272 if (current_time
- si
->roam_event
< config
.roam_scan_interval
)
275 if (find_better_candidate(si
, &ev
) ||
276 si
->roam_scan_done
> si
->roam_event
) {
277 usteer_roam_set_state(si
, ROAM_TRIGGER_SCAN_DONE
, &ev
);
281 if (config
.roam_scan_tries
&&
282 si
->roam_tries
>= config
.roam_scan_tries
) {
283 usteer_roam_set_state(si
, ROAM_TRIGGER_WAIT_KICK
, &ev
);
287 usteer_ubus_trigger_client_scan(si
);
288 usteer_roam_set_state(si
, ROAM_TRIGGER_SCAN
, &ev
);
291 case ROAM_TRIGGER_IDLE
:
292 if (find_better_candidate(si
, &ev
)) {
293 usteer_roam_set_state(si
, ROAM_TRIGGER_SCAN_DONE
, &ev
);
297 usteer_roam_set_state(si
, ROAM_TRIGGER_SCAN
, &ev
);
300 case ROAM_TRIGGER_SCAN_DONE
:
301 /* Check for stale scan results, kick back to SCAN state if necessary */
302 if (current_time
- si
->roam_scan_done
> 2 * config
.roam_scan_interval
) {
303 usteer_roam_set_state(si
, ROAM_TRIGGER_SCAN
, &ev
);
307 if (find_better_candidate(si
, &ev
))
308 usteer_roam_set_state(si
, ROAM_TRIGGER_WAIT_KICK
, &ev
);
312 case ROAM_TRIGGER_WAIT_KICK
:
313 if (si
->signal
> min_signal
)
316 usteer_roam_set_state(si
, ROAM_TRIGGER_NOTIFY_KICK
, &ev
);
317 usteer_ubus_notify_client_disassoc(si
);
319 case ROAM_TRIGGER_NOTIFY_KICK
:
320 if (current_time
- si
->roam_event
< config
.roam_kick_delay
* 100)
323 usteer_roam_set_state(si
, ROAM_TRIGGER_KICK
, &ev
);
325 case ROAM_TRIGGER_KICK
:
326 usteer_ubus_kick_client(si
);
327 usteer_roam_set_state(si
, ROAM_TRIGGER_IDLE
, &ev
);
335 usteer_local_node_roam_check(struct usteer_local_node
*ln
, struct uevent
*ev
)
340 if (config
.roam_scan_snr
)
341 min_signal
= config
.roam_scan_snr
;
342 else if (config
.roam_trigger_snr
)
343 min_signal
= config
.roam_trigger_snr
;
347 usteer_update_time();
348 min_signal
= snr_to_signal(&ln
->node
, min_signal
);
350 list_for_each_entry(si
, &ln
->node
.sta_info
, node_list
) {
351 if (si
->connected
!= STA_CONNECTED
|| si
->signal
>= min_signal
||
352 current_time
- si
->roam_kick
< config
.roam_trigger_interval
) {
353 usteer_roam_set_state(si
, ROAM_TRIGGER_IDLE
, ev
);
358 * If the state machine kicked a client, other clients should wait
359 * until the next turn
361 if (usteer_roam_trigger_sm(si
))
367 usteer_local_node_snr_kick(struct usteer_local_node
*ln
)
370 .node_local
= &ln
->node
,
378 min_signal
= snr_to_signal(&ln
->node
, config
.min_snr
);
379 ev
.threshold
.ref
= min_signal
;
381 list_for_each_entry(si
, &ln
->node
.sta_info
, node_list
) {
382 if (si
->connected
!= STA_CONNECTED
)
385 if (si
->signal
>= min_signal
)
390 ev
.type
= UEV_SIGNAL_KICK
;
391 ev
.threshold
.cur
= si
->signal
;
392 ev
.count
= si
->kick_count
;
395 usteer_ubus_kick_client(si
);
401 usteer_local_node_kick(struct usteer_local_node
*ln
)
403 struct usteer_node
*node
= &ln
->node
;
404 struct sta_info
*kick1
= NULL
, *kick2
= NULL
;
405 struct sta_info
*candidate
= NULL
;
408 .node_local
= &ln
->node
,
410 unsigned int min_count
= DIV_ROUND_UP(config
.load_kick_delay
, config
.local_sta_update
);
412 usteer_local_node_roam_check(ln
, &ev
);
413 usteer_local_node_snr_kick(ln
);
415 if (!config
.load_kick_enabled
|| !config
.load_kick_threshold
||
416 !config
.load_kick_delay
)
419 if (node
->load
< config
.load_kick_threshold
) {
420 if (!ln
->load_thr_count
)
423 ln
->load_thr_count
= 0;
424 ev
.type
= UEV_LOAD_KICK_RESET
;
425 ev
.threshold
.cur
= node
->load
;
426 ev
.threshold
.ref
= config
.load_kick_threshold
;
430 if (++ln
->load_thr_count
<= min_count
) {
431 if (ln
->load_thr_count
> 1)
434 ev
.type
= UEV_LOAD_KICK_TRIGGER
;
435 ev
.threshold
.cur
= node
->load
;
436 ev
.threshold
.ref
= config
.load_kick_threshold
;
440 ln
->load_thr_count
= 0;
441 if (node
->n_assoc
< config
.load_kick_min_clients
) {
442 ev
.type
= UEV_LOAD_KICK_MIN_CLIENTS
;
443 ev
.threshold
.cur
= node
->n_assoc
;
444 ev
.threshold
.ref
= config
.load_kick_min_clients
;
448 list_for_each_entry(si
, &ln
->node
.sta_info
, node_list
) {
449 struct sta_info
*tmp
;
451 if (si
->connected
!= STA_CONNECTED
)
454 if (is_more_kickable(kick1
, si
))
457 tmp
= find_better_candidate(si
, NULL
);
461 if (is_more_kickable(kick2
, si
)) {
468 ev
.type
= UEV_LOAD_KICK_NO_CLIENT
;
477 ev
.type
= UEV_LOAD_KICK_CLIENT
;
479 ev
.si_other
= candidate
;
480 ev
.count
= kick1
->kick_count
;
482 usteer_ubus_kick_client(kick1
);