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
&& !config
.assoc_steering
)
161 min_signal
= snr_to_signal(si
->node
, config
.min_connect_snr
);
162 if (si
->signal
< min_signal
) {
163 ev
.reason
= UEV_REASON_LOW_SIGNAL
;
164 ev
.threshold
.cur
= si
->signal
;
165 ev
.threshold
.ref
= min_signal
;
170 if (current_time
- si
->created
< config
.initial_connect_delay
) {
171 ev
.reason
= UEV_REASON_CONNECT_DELAY
;
172 ev
.threshold
.cur
= current_time
- si
->created
;
173 ev
.threshold
.ref
= config
.initial_connect_delay
;
178 if (!find_better_candidate(si
, &ev
))
181 ev
.reason
= UEV_REASON_BETTER_CANDIDATE
;
182 ev
.node_cur
= si
->node
;
187 case EVENT_TYPE_PROBE
:
188 ev
.type
= UEV_PROBE_REQ_ACCEPT
;
190 case EVENT_TYPE_ASSOC
:
191 ev
.type
= UEV_ASSOC_REQ_ACCEPT
;
193 case EVENT_TYPE_AUTH
:
194 ev
.type
= UEV_AUTH_REQ_ACCEPT
;
203 if (!ret
&& si
->stats
[type
].blocked_cur
>= config
.max_retry_band
) {
204 ev
.reason
= UEV_REASON_RETRY_EXCEEDED
;
205 ev
.threshold
.cur
= si
->stats
[type
].blocked_cur
;
206 ev
.threshold
.ref
= config
.max_retry_band
;
214 is_more_kickable(struct sta_info
*si_cur
, struct sta_info
*si_new
)
219 if (si_new
->kick_count
> si_cur
->kick_count
)
222 return si_cur
->signal
> si_new
->signal
;
226 usteer_roam_set_state(struct sta_info
*si
, enum roam_trigger_state state
,
229 si
->roam_event
= current_time
;
231 if (si
->roam_state
== state
) {
232 if (si
->roam_state
== ROAM_TRIGGER_IDLE
) {
242 si
->roam_state
= state
;
247 usteer_roam_trigger_sm(struct sta_info
*si
)
254 min_signal
= snr_to_signal(si
->node
, config
.roam_trigger_snr
);
256 switch (si
->roam_state
) {
257 case ROAM_TRIGGER_SCAN
:
258 if (current_time
- si
->roam_event
< config
.roam_scan_interval
)
261 if (find_better_candidate(si
, &ev
) ||
262 si
->roam_scan_done
> si
->roam_event
) {
263 usteer_roam_set_state(si
, ROAM_TRIGGER_SCAN_DONE
, &ev
);
267 if (config
.roam_scan_tries
&&
268 si
->roam_tries
>= config
.roam_scan_tries
) {
269 usteer_roam_set_state(si
, ROAM_TRIGGER_WAIT_KICK
, &ev
);
273 usteer_ubus_trigger_client_scan(si
);
274 usteer_roam_set_state(si
, ROAM_TRIGGER_SCAN
, &ev
);
277 case ROAM_TRIGGER_IDLE
:
278 if (find_better_candidate(si
, &ev
)) {
279 usteer_roam_set_state(si
, ROAM_TRIGGER_SCAN_DONE
, &ev
);
283 usteer_roam_set_state(si
, ROAM_TRIGGER_SCAN
, &ev
);
286 case ROAM_TRIGGER_SCAN_DONE
:
287 /* Check for stale scan results, kick back to SCAN state if necessary */
288 if (current_time
- si
->roam_scan_done
> 2 * config
.roam_scan_interval
) {
289 usteer_roam_set_state(si
, ROAM_TRIGGER_SCAN
, &ev
);
293 if (find_better_candidate(si
, &ev
))
294 usteer_roam_set_state(si
, ROAM_TRIGGER_WAIT_KICK
, &ev
);
298 case ROAM_TRIGGER_WAIT_KICK
:
299 if (si
->signal
> min_signal
)
302 usteer_roam_set_state(si
, ROAM_TRIGGER_NOTIFY_KICK
, &ev
);
303 usteer_ubus_notify_client_disassoc(si
);
305 case ROAM_TRIGGER_NOTIFY_KICK
:
306 if (current_time
- si
->roam_event
< config
.roam_kick_delay
* 100)
309 usteer_roam_set_state(si
, ROAM_TRIGGER_KICK
, &ev
);
311 case ROAM_TRIGGER_KICK
:
312 usteer_ubus_kick_client(si
);
313 usteer_roam_set_state(si
, ROAM_TRIGGER_IDLE
, &ev
);
321 usteer_local_node_roam_check(struct usteer_local_node
*ln
, struct uevent
*ev
)
326 if (config
.roam_scan_snr
)
327 min_signal
= config
.roam_scan_snr
;
328 else if (config
.roam_trigger_snr
)
329 min_signal
= config
.roam_trigger_snr
;
333 usteer_update_time();
334 min_signal
= snr_to_signal(&ln
->node
, min_signal
);
336 list_for_each_entry(si
, &ln
->node
.sta_info
, node_list
) {
337 if (!si
->connected
|| si
->signal
>= min_signal
||
338 current_time
- si
->roam_kick
< config
.roam_trigger_interval
) {
339 usteer_roam_set_state(si
, ROAM_TRIGGER_IDLE
, ev
);
344 * If the state machine kicked a client, other clients should wait
345 * until the next turn
347 if (usteer_roam_trigger_sm(si
))
353 usteer_local_node_snr_kick(struct usteer_local_node
*ln
)
356 .node_local
= &ln
->node
,
364 min_signal
= snr_to_signal(&ln
->node
, config
.min_snr
);
365 ev
.threshold
.ref
= min_signal
;
367 list_for_each_entry(si
, &ln
->node
.sta_info
, node_list
) {
371 if (si
->signal
>= min_signal
)
376 ev
.type
= UEV_SIGNAL_KICK
;
377 ev
.threshold
.cur
= si
->signal
;
378 ev
.count
= si
->kick_count
;
381 usteer_ubus_kick_client(si
);
387 usteer_local_node_kick(struct usteer_local_node
*ln
)
389 struct usteer_node
*node
= &ln
->node
;
390 struct sta_info
*kick1
= NULL
, *kick2
= NULL
;
391 struct sta_info
*candidate
= NULL
;
394 .node_local
= &ln
->node
,
396 unsigned int min_count
= DIV_ROUND_UP(config
.load_kick_delay
, config
.local_sta_update
);
398 usteer_local_node_roam_check(ln
, &ev
);
399 usteer_local_node_snr_kick(ln
);
401 if (!config
.load_kick_enabled
|| !config
.load_kick_threshold
||
402 !config
.load_kick_delay
)
405 if (node
->load
< config
.load_kick_threshold
) {
406 if (!ln
->load_thr_count
)
409 ln
->load_thr_count
= 0;
410 ev
.type
= UEV_LOAD_KICK_RESET
;
411 ev
.threshold
.cur
= node
->load
;
412 ev
.threshold
.ref
= config
.load_kick_threshold
;
416 if (++ln
->load_thr_count
<= min_count
) {
417 if (ln
->load_thr_count
> 1)
420 ev
.type
= UEV_LOAD_KICK_TRIGGER
;
421 ev
.threshold
.cur
= node
->load
;
422 ev
.threshold
.ref
= config
.load_kick_threshold
;
426 ln
->load_thr_count
= 0;
427 if (node
->n_assoc
< config
.load_kick_min_clients
) {
428 ev
.type
= UEV_LOAD_KICK_MIN_CLIENTS
;
429 ev
.threshold
.cur
= node
->n_assoc
;
430 ev
.threshold
.ref
= config
.load_kick_min_clients
;
434 list_for_each_entry(si
, &ln
->node
.sta_info
, node_list
) {
435 struct sta_info
*tmp
;
440 if (is_more_kickable(kick1
, si
))
443 tmp
= find_better_candidate(si
, NULL
);
447 if (is_more_kickable(kick2
, si
)) {
454 ev
.type
= UEV_LOAD_KICK_NO_CLIENT
;
463 ev
.type
= UEV_LOAD_KICK_CLIENT
;
465 ev
.si_other
= candidate
;
466 ev
.count
= kick1
->kick_count
;
468 usteer_ubus_kick_client(kick1
);