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Linux 5.1.15
[linux/fpc-iii.git] / net / mac80211 / mesh_plink.c
blob8afd0ece94c93b03053450c1c82e2afd5268fc91
1 /*
2 * Copyright (c) 2008, 2009 open80211s Ltd.
3 * Copyright (C) 2019 Intel Corporation
4 * Author: Luis Carlos Cobo <luisca@cozybit.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10 #include <linux/gfp.h>
11 #include <linux/kernel.h>
12 #include <linux/random.h>
13 #include <linux/rculist.h>
14
15 #include "ieee80211_i.h"
16 #include "rate.h"
17 #include "mesh.h"
18
19 #define PLINK_CNF_AID(mgmt) ((mgmt)->u.action.u.self_prot.variable + 2)
20 #define PLINK_GET_LLID(p) (p + 2)
21 #define PLINK_GET_PLID(p) (p + 4)
22
23 #define mod_plink_timer(s, t) (mod_timer(&s->mesh->plink_timer, \
24 jiffies + msecs_to_jiffies(t)))
25
26 enum plink_event {
27 PLINK_UNDEFINED,
28 OPN_ACPT,
29 OPN_RJCT,
30 OPN_IGNR,
31 CNF_ACPT,
32 CNF_RJCT,
33 CNF_IGNR,
34 CLS_ACPT,
35 CLS_IGNR
36 };
37
38 static const char * const mplstates[] = {
39 [NL80211_PLINK_LISTEN] = "LISTEN",
40 [NL80211_PLINK_OPN_SNT] = "OPN-SNT",
41 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
42 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
43 [NL80211_PLINK_ESTAB] = "ESTAB",
44 [NL80211_PLINK_HOLDING] = "HOLDING",
45 [NL80211_PLINK_BLOCKED] = "BLOCKED"
46 };
47
48 static const char * const mplevents[] = {
49 [PLINK_UNDEFINED] = "NONE",
50 [OPN_ACPT] = "OPN_ACPT",
51 [OPN_RJCT] = "OPN_RJCT",
52 [OPN_IGNR] = "OPN_IGNR",
53 [CNF_ACPT] = "CNF_ACPT",
54 [CNF_RJCT] = "CNF_RJCT",
55 [CNF_IGNR] = "CNF_IGNR",
56 [CLS_ACPT] = "CLS_ACPT",
57 [CLS_IGNR] = "CLS_IGNR"
58 };
59
60 /* We only need a valid sta if user configured a minimum rssi_threshold. */
61 static bool rssi_threshold_check(struct ieee80211_sub_if_data *sdata,
62 struct sta_info *sta)
63 {
64 s32 rssi_threshold = sdata->u.mesh.mshcfg.rssi_threshold;
65 return rssi_threshold == 0 ||
66 (sta &&
67 (s8)-ewma_signal_read(&sta->rx_stats_avg.signal) >
68 rssi_threshold);
69 }
70
71 /**
72 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
73 *
74 * @sta: mesh peer link to restart
75 *
76 * Locking: this function must be called holding sta->mesh->plink_lock
77 */
78 static inline void mesh_plink_fsm_restart(struct sta_info *sta)
79 {
80 lockdep_assert_held(&sta->mesh->plink_lock);
81 sta->mesh->plink_state = NL80211_PLINK_LISTEN;
82 sta->mesh->llid = sta->mesh->plid = sta->mesh->reason = 0;
83 sta->mesh->plink_retries = 0;
84 }
85
86 /*
87 * mesh_set_short_slot_time - enable / disable ERP short slot time.
88 *
89 * The standard indirectly mandates mesh STAs to turn off short slot time by
90 * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we
91 * can't be sneaky about it. Enable short slot time if all mesh STAs in the
92 * MBSS support ERP rates.
93 *
94 * Returns BSS_CHANGED_ERP_SLOT or 0 for no change.
95 */
96 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata)
97 {
98 struct ieee80211_local *local = sdata->local;
99 struct ieee80211_supported_band *sband;
100 struct sta_info *sta;
101 u32 erp_rates = 0, changed = 0;
102 int i;
103 bool short_slot = false;
104
105 sband = ieee80211_get_sband(sdata);
106 if (!sband)
107 return changed;
108
109 if (sband->band == NL80211_BAND_5GHZ) {
110 /* (IEEE 802.11-2012 19.4.5) */
111 short_slot = true;
112 goto out;
113 } else if (sband->band != NL80211_BAND_2GHZ) {
114 goto out;
115 }
116
117 for (i = 0; i < sband->n_bitrates; i++)
118 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)
119 erp_rates |= BIT(i);
120
121 if (!erp_rates)
122 goto out;
123
124 rcu_read_lock();
125 list_for_each_entry_rcu(sta, &local->sta_list, list) {
126 if (sdata != sta->sdata ||
127 sta->mesh->plink_state != NL80211_PLINK_ESTAB)
128 continue;
129
130 short_slot = false;
131 if (erp_rates & sta->sta.supp_rates[sband->band])
132 short_slot = true;
133 else
134 break;
135 }
136 rcu_read_unlock();
137
138 out:
139 if (sdata->vif.bss_conf.use_short_slot != short_slot) {
140 sdata->vif.bss_conf.use_short_slot = short_slot;
141 changed = BSS_CHANGED_ERP_SLOT;
142 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n",
143 sdata->vif.addr, short_slot);
144 }
145 return changed;
146 }
147
148 /**
149 * mesh_set_ht_prot_mode - set correct HT protection mode
150 *
151 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
152 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
153 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
154 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode
155 * is selected if all peers in our 20/40MHz MBSS support HT and atleast one
156 * HT20 peer is present. Otherwise no-protection mode is selected.
157 */
158 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
159 {
160 struct ieee80211_local *local = sdata->local;
161 struct sta_info *sta;
162 u16 ht_opmode;
163 bool non_ht_sta = false, ht20_sta = false;
164
165 switch (sdata->vif.bss_conf.chandef.width) {
166 case NL80211_CHAN_WIDTH_20_NOHT:
167 case NL80211_CHAN_WIDTH_5:
168 case NL80211_CHAN_WIDTH_10:
169 return 0;
170 default:
171 break;
172 }
173
174 rcu_read_lock();
175 list_for_each_entry_rcu(sta, &local->sta_list, list) {
176 if (sdata != sta->sdata ||
177 sta->mesh->plink_state != NL80211_PLINK_ESTAB)
178 continue;
179
180 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20)
181 continue;
182
183 if (!sta->sta.ht_cap.ht_supported) {
184 mpl_dbg(sdata, "nonHT sta (%pM) is present\n",
185 sta->sta.addr);
186 non_ht_sta = true;
187 break;
188 }
189
190 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr);
191 ht20_sta = true;
192 }
193 rcu_read_unlock();
194
195 if (non_ht_sta)
196 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
197 else if (ht20_sta &&
198 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20)
199 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
200 else
201 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
202
203 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode)
204 return 0;
205
206 sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
207 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
208 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode);
209 return BSS_CHANGED_HT;
210 }
211
212 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
213 struct sta_info *sta,
214 enum ieee80211_self_protected_actioncode action,
215 u8 *da, u16 llid, u16 plid, u16 reason)
216 {
217 struct ieee80211_local *local = sdata->local;
218 struct sk_buff *skb;
219 struct ieee80211_tx_info *info;
220 struct ieee80211_mgmt *mgmt;
221 bool include_plid = false;
222 u16 peering_proto = 0;
223 u8 *pos, ie_len = 4;
224 int hdr_len = offsetofend(struct ieee80211_mgmt, u.action.u.self_prot);
225 int err = -ENOMEM;
226
227 skb = dev_alloc_skb(local->tx_headroom +
228 hdr_len +
229 2 + /* capability info */
230 2 + /* AID */
231 2 + 8 + /* supported rates */
232 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
233 2 + sdata->u.mesh.mesh_id_len +
234 2 + sizeof(struct ieee80211_meshconf_ie) +
235 2 + sizeof(struct ieee80211_ht_cap) +
236 2 + sizeof(struct ieee80211_ht_operation) +
237 2 + sizeof(struct ieee80211_vht_cap) +
238 2 + sizeof(struct ieee80211_vht_operation) +
239 2 + 8 + /* peering IE */
240 sdata->u.mesh.ie_len);
241 if (!skb)
242 return err;
243 info = IEEE80211_SKB_CB(skb);
244 skb_reserve(skb, local->tx_headroom);
245 mgmt = skb_put_zero(skb, hdr_len);
246 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
247 IEEE80211_STYPE_ACTION);
248 memcpy(mgmt->da, da, ETH_ALEN);
249 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
250 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
251 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
252 mgmt->u.action.u.self_prot.action_code = action;
253
254 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
255 struct ieee80211_supported_band *sband;
256 enum nl80211_band band;
257
258 sband = ieee80211_get_sband(sdata);
259 if (!sband) {
260 err = -EINVAL;
261 goto free;
262 }
263 band = sband->band;
264
265 /* capability info */
266 pos = skb_put_zero(skb, 2);
267 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
268 /* AID */
269 pos = skb_put(skb, 2);
270 put_unaligned_le16(sta->sta.aid, pos);
271 }
272 if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
273 ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
274 mesh_add_rsn_ie(sdata, skb) ||
275 mesh_add_meshid_ie(sdata, skb) ||
276 mesh_add_meshconf_ie(sdata, skb))
277 goto free;
278 } else { /* WLAN_SP_MESH_PEERING_CLOSE */
279 info->flags |= IEEE80211_TX_CTL_NO_ACK;
280 if (mesh_add_meshid_ie(sdata, skb))
281 goto free;
282 }
283
284 /* Add Mesh Peering Management element */
285 switch (action) {
286 case WLAN_SP_MESH_PEERING_OPEN:
287 break;
288 case WLAN_SP_MESH_PEERING_CONFIRM:
289 ie_len += 2;
290 include_plid = true;
291 break;
292 case WLAN_SP_MESH_PEERING_CLOSE:
293 if (plid) {
294 ie_len += 2;
295 include_plid = true;
296 }
297 ie_len += 2; /* reason code */
298 break;
299 default:
300 err = -EINVAL;
301 goto free;
302 }
303
304 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
305 goto free;
306
307 pos = skb_put(skb, 2 + ie_len);
308 *pos++ = WLAN_EID_PEER_MGMT;
309 *pos++ = ie_len;
310 memcpy(pos, &peering_proto, 2);
311 pos += 2;
312 put_unaligned_le16(llid, pos);
313 pos += 2;
314 if (include_plid) {
315 put_unaligned_le16(plid, pos);
316 pos += 2;
317 }
318 if (action == WLAN_SP_MESH_PEERING_CLOSE) {
319 put_unaligned_le16(reason, pos);
320 pos += 2;
321 }
322
323 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
324 if (mesh_add_ht_cap_ie(sdata, skb) ||
325 mesh_add_ht_oper_ie(sdata, skb) ||
326 mesh_add_vht_cap_ie(sdata, skb) ||
327 mesh_add_vht_oper_ie(sdata, skb))
328 goto free;
329 }
330
331 if (mesh_add_vendor_ies(sdata, skb))
332 goto free;
333
334 ieee80211_tx_skb(sdata, skb);
335 return 0;
336 free:
337 kfree_skb(skb);
338 return err;
339 }
340
341 /**
342 * __mesh_plink_deactivate - deactivate mesh peer link
343 *
344 * @sta: mesh peer link to deactivate
345 *
346 * Mesh paths with this peer as next hop should be flushed
347 * by the caller outside of plink_lock.
348 *
349 * Returns beacon changed flag if the beacon content changed.
350 *
351 * Locking: the caller must hold sta->mesh->plink_lock
352 */
353 static u32 __mesh_plink_deactivate(struct sta_info *sta)
354 {
355 struct ieee80211_sub_if_data *sdata = sta->sdata;
356 u32 changed = 0;
357
358 lockdep_assert_held(&sta->mesh->plink_lock);
359
360 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
361 changed = mesh_plink_dec_estab_count(sdata);
362 sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
363
364 ieee80211_mps_sta_status_update(sta);
365 changed |= ieee80211_mps_set_sta_local_pm(sta,
366 NL80211_MESH_POWER_UNKNOWN);
367
368 return changed;
369 }
370
371 /**
372 * mesh_plink_deactivate - deactivate mesh peer link
373 *
374 * @sta: mesh peer link to deactivate
375 *
376 * All mesh paths with this peer as next hop will be flushed
377 */
378 u32 mesh_plink_deactivate(struct sta_info *sta)
379 {
380 struct ieee80211_sub_if_data *sdata = sta->sdata;
381 u32 changed;
382
383 spin_lock_bh(&sta->mesh->plink_lock);
384 changed = __mesh_plink_deactivate(sta);
385
386 if (!sdata->u.mesh.user_mpm) {
387 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED;
388 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE,
389 sta->sta.addr, sta->mesh->llid,
390 sta->mesh->plid, sta->mesh->reason);
391 }
392 spin_unlock_bh(&sta->mesh->plink_lock);
393 if (!sdata->u.mesh.user_mpm)
394 del_timer_sync(&sta->mesh->plink_timer);
395 mesh_path_flush_by_nexthop(sta);
396
397 /* make sure no readers can access nexthop sta from here on */
398 synchronize_net();
399
400 return changed;
401 }
402
403 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
404 struct sta_info *sta,
405 struct ieee802_11_elems *elems)
406 {
407 struct ieee80211_local *local = sdata->local;
408 struct ieee80211_supported_band *sband;
409 u32 rates, basic_rates = 0, changed = 0;
410 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth;
411
412 sband = ieee80211_get_sband(sdata);
413 if (!sband)
414 return;
415
416 rates = ieee80211_sta_get_rates(sdata, elems, sband->band,
417 &basic_rates);
418
419 spin_lock_bh(&sta->mesh->plink_lock);
420 sta->rx_stats.last_rx = jiffies;
421
422 /* rates and capabilities don't change during peering */
423 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB &&
424 sta->mesh->processed_beacon)
425 goto out;
426 sta->mesh->processed_beacon = true;
427
428 if (sta->sta.supp_rates[sband->band] != rates)
429 changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
430 sta->sta.supp_rates[sband->band] = rates;
431
432 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
433 elems->ht_cap_elem, sta))
434 changed |= IEEE80211_RC_BW_CHANGED;
435
436 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
437 elems->vht_cap_elem, sta);
438
439 if (bw != sta->sta.bandwidth)
440 changed |= IEEE80211_RC_BW_CHANGED;
441
442 /* HT peer is operating 20MHz-only */
443 if (elems->ht_operation &&
444 !(elems->ht_operation->ht_param &
445 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
446 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20)
447 changed |= IEEE80211_RC_BW_CHANGED;
448 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20;
449 }
450
451 if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
452 rate_control_rate_init(sta);
453 else
454 rate_control_rate_update(local, sband, sta, changed);
455 out:
456 spin_unlock_bh(&sta->mesh->plink_lock);
457 }
458
459 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata)
460 {
461 struct sta_info *sta;
462 unsigned long *aid_map;
463 int aid;
464
465 aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1),
466 sizeof(*aid_map), GFP_KERNEL);
467 if (!aid_map)
468 return -ENOMEM;
469
470 /* reserve aid 0 for mcast indication */
471 __set_bit(0, aid_map);
472
473 rcu_read_lock();
474 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list)
475 __set_bit(sta->sta.aid, aid_map);
476 rcu_read_unlock();
477
478 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1);
479 kfree(aid_map);
480
481 if (aid > IEEE80211_MAX_AID)
482 return -ENOBUFS;
483
484 return aid;
485 }
486
487 static struct sta_info *
488 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
489 {
490 struct sta_info *sta;
491 int aid;
492
493 if (sdata->local->num_sta >= MESH_MAX_PLINKS)
494 return NULL;
495
496 aid = mesh_allocate_aid(sdata);
497 if (aid < 0)
498 return NULL;
499
500 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
501 if (!sta)
502 return NULL;
503
504 sta->mesh->plink_state = NL80211_PLINK_LISTEN;
505 sta->sta.wme = true;
506 sta->sta.aid = aid;
507
508 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
509 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
510 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
511
512 return sta;
513 }
514
515 static struct sta_info *
516 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
517 struct ieee802_11_elems *elems,
518 struct ieee80211_rx_status *rx_status)
519 {
520 struct sta_info *sta = NULL;
521
522 /* Userspace handles station allocation */
523 if (sdata->u.mesh.user_mpm ||
524 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) {
525 if (mesh_peer_accepts_plinks(elems) &&
526 mesh_plink_availables(sdata)) {
527 int sig = 0;
528
529 if (ieee80211_hw_check(&sdata->local->hw, SIGNAL_DBM))
530 sig = rx_status->signal;
531
532 cfg80211_notify_new_peer_candidate(sdata->dev, addr,
533 elems->ie_start,
534 elems->total_len,
535 sig, GFP_KERNEL);
536 }
537 } else
538 sta = __mesh_sta_info_alloc(sdata, addr);
539
540 return sta;
541 }
542
543 /*
544 * mesh_sta_info_get - return mesh sta info entry for @addr.
545 *
546 * @sdata: local meshif
547 * @addr: peer's address
548 * @elems: IEs from beacon or mesh peering frame.
549 * @rx_status: rx status for the frame for signal reporting
550 *
551 * Return existing or newly allocated sta_info under RCU read lock.
552 * (re)initialize with given IEs.
553 */
554 static struct sta_info *
555 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
556 u8 *addr, struct ieee802_11_elems *elems,
557 struct ieee80211_rx_status *rx_status) __acquires(RCU)
558 {
559 struct sta_info *sta = NULL;
560
561 rcu_read_lock();
562 sta = sta_info_get(sdata, addr);
563 if (sta) {
564 mesh_sta_info_init(sdata, sta, elems);
565 } else {
566 rcu_read_unlock();
567 /* can't run atomic */
568 sta = mesh_sta_info_alloc(sdata, addr, elems, rx_status);
569 if (!sta) {
570 rcu_read_lock();
571 return NULL;
572 }
573
574 mesh_sta_info_init(sdata, sta, elems);
575
576 if (sta_info_insert_rcu(sta))
577 return NULL;
578 }
579
580 return sta;
581 }
582
583 /*
584 * mesh_neighbour_update - update or initialize new mesh neighbor.
585 *
586 * @sdata: local meshif
587 * @addr: peer's address
588 * @elems: IEs from beacon or mesh peering frame
589 * @rx_status: rx status for the frame for signal reporting
590 *
591 * Initiates peering if appropriate.
592 */
593 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
594 u8 *hw_addr,
595 struct ieee802_11_elems *elems,
596 struct ieee80211_rx_status *rx_status)
597 {
598 struct sta_info *sta;
599 u32 changed = 0;
600
601 sta = mesh_sta_info_get(sdata, hw_addr, elems, rx_status);
602 if (!sta)
603 goto out;
604
605 sta->mesh->connected_to_gate = elems->mesh_config->meshconf_form &
606 IEEE80211_MESHCONF_FORM_CONNECTED_TO_GATE;
607
608 if (mesh_peer_accepts_plinks(elems) &&
609 sta->mesh->plink_state == NL80211_PLINK_LISTEN &&
610 sdata->u.mesh.accepting_plinks &&
611 sdata->u.mesh.mshcfg.auto_open_plinks &&
612 rssi_threshold_check(sdata, sta))
613 changed = mesh_plink_open(sta);
614
615 ieee80211_mps_frame_release(sta, elems);
616 out:
617 rcu_read_unlock();
618 ieee80211_mbss_info_change_notify(sdata, changed);
619 }
620
621 void mesh_plink_timer(struct timer_list *t)
622 {
623 struct mesh_sta *mesh = from_timer(mesh, t, plink_timer);
624 struct sta_info *sta;
625 u16 reason = 0;
626 struct ieee80211_sub_if_data *sdata;
627 struct mesh_config *mshcfg;
628 enum ieee80211_self_protected_actioncode action = 0;
629
630 /*
631 * This STA is valid because sta_info_destroy() will
632 * del_timer_sync() this timer after having made sure
633 * it cannot be readded (by deleting the plink.)
634 */
635 sta = mesh->plink_sta;
636
637 if (sta->sdata->local->quiescing)
638 return;
639
640 spin_lock_bh(&sta->mesh->plink_lock);
641
642 /* If a timer fires just before a state transition on another CPU,
643 * we may have already extended the timeout and changed state by the
644 * time we've acquired the lock and arrived here. In that case,
645 * skip this timer and wait for the new one.
646 */
647 if (time_before(jiffies, sta->mesh->plink_timer.expires)) {
648 mpl_dbg(sta->sdata,
649 "Ignoring timer for %pM in state %s (timer adjusted)",
650 sta->sta.addr, mplstates[sta->mesh->plink_state]);
651 spin_unlock_bh(&sta->mesh->plink_lock);
652 return;
653 }
654
655 /* del_timer() and handler may race when entering these states */
656 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN ||
657 sta->mesh->plink_state == NL80211_PLINK_ESTAB) {
658 mpl_dbg(sta->sdata,
659 "Ignoring timer for %pM in state %s (timer deleted)",
660 sta->sta.addr, mplstates[sta->mesh->plink_state]);
661 spin_unlock_bh(&sta->mesh->plink_lock);
662 return;
663 }
664
665 mpl_dbg(sta->sdata,
666 "Mesh plink timer for %pM fired on state %s\n",
667 sta->sta.addr, mplstates[sta->mesh->plink_state]);
668 sdata = sta->sdata;
669 mshcfg = &sdata->u.mesh.mshcfg;
670
671 switch (sta->mesh->plink_state) {
672 case NL80211_PLINK_OPN_RCVD:
673 case NL80211_PLINK_OPN_SNT:
674 /* retry timer */
675 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) {
676 u32 rand;
677 mpl_dbg(sta->sdata,
678 "Mesh plink for %pM (retry, timeout): %d %d\n",
679 sta->sta.addr, sta->mesh->plink_retries,
680 sta->mesh->plink_timeout);
681 get_random_bytes(&rand, sizeof(u32));
682 sta->mesh->plink_timeout = sta->mesh->plink_timeout +
683 rand % sta->mesh->plink_timeout;
684 ++sta->mesh->plink_retries;
685 mod_plink_timer(sta, sta->mesh->plink_timeout);
686 action = WLAN_SP_MESH_PEERING_OPEN;
687 break;
688 }
689 reason = WLAN_REASON_MESH_MAX_RETRIES;
690 /* fall through */
691 case NL80211_PLINK_CNF_RCVD:
692 /* confirm timer */
693 if (!reason)
694 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT;
695 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
696 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
697 action = WLAN_SP_MESH_PEERING_CLOSE;
698 break;
699 case NL80211_PLINK_HOLDING:
700 /* holding timer */
701 del_timer(&sta->mesh->plink_timer);
702 mesh_plink_fsm_restart(sta);
703 break;
704 default:
705 break;
706 }
707 spin_unlock_bh(&sta->mesh->plink_lock);
708 if (action)
709 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
710 sta->mesh->llid, sta->mesh->plid, reason);
711 }
712
713 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout)
714 {
715 sta->mesh->plink_timeout = timeout;
716 mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout));
717 }
718
719 static bool llid_in_use(struct ieee80211_sub_if_data *sdata,
720 u16 llid)
721 {
722 struct ieee80211_local *local = sdata->local;
723 bool in_use = false;
724 struct sta_info *sta;
725
726 rcu_read_lock();
727 list_for_each_entry_rcu(sta, &local->sta_list, list) {
728 if (sdata != sta->sdata)
729 continue;
730
731 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) {
732 in_use = true;
733 break;
734 }
735 }
736 rcu_read_unlock();
737
738 return in_use;
739 }
740
741 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata)
742 {
743 u16 llid;
744
745 do {
746 get_random_bytes(&llid, sizeof(llid));
747 } while (llid_in_use(sdata, llid));
748
749 return llid;
750 }
751
752 u32 mesh_plink_open(struct sta_info *sta)
753 {
754 struct ieee80211_sub_if_data *sdata = sta->sdata;
755 u32 changed;
756
757 if (!test_sta_flag(sta, WLAN_STA_AUTH))
758 return 0;
759
760 spin_lock_bh(&sta->mesh->plink_lock);
761 sta->mesh->llid = mesh_get_new_llid(sdata);
762 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN &&
763 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) {
764 spin_unlock_bh(&sta->mesh->plink_lock);
765 return 0;
766 }
767 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT;
768 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
769 spin_unlock_bh(&sta->mesh->plink_lock);
770 mpl_dbg(sdata,
771 "Mesh plink: starting establishment with %pM\n",
772 sta->sta.addr);
773
774 /* set the non-peer mode to active during peering */
775 changed = ieee80211_mps_local_status_update(sdata);
776
777 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN,
778 sta->sta.addr, sta->mesh->llid, 0, 0);
779 return changed;
780 }
781
782 u32 mesh_plink_block(struct sta_info *sta)
783 {
784 u32 changed;
785
786 spin_lock_bh(&sta->mesh->plink_lock);
787 changed = __mesh_plink_deactivate(sta);
788 sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
789 spin_unlock_bh(&sta->mesh->plink_lock);
790 mesh_path_flush_by_nexthop(sta);
791
792 return changed;
793 }
794
795 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata,
796 struct sta_info *sta,
797 enum plink_event event)
798 {
799 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
800 u16 reason = (event == CLS_ACPT) ?
801 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG;
802
803 sta->mesh->reason = reason;
804 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
805 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
806 }
807
808 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata,
809 struct sta_info *sta)
810 {
811 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
812 u32 changed = 0;
813
814 del_timer(&sta->mesh->plink_timer);
815 sta->mesh->plink_state = NL80211_PLINK_ESTAB;
816 changed |= mesh_plink_inc_estab_count(sdata);
817 changed |= mesh_set_ht_prot_mode(sdata);
818 changed |= mesh_set_short_slot_time(sdata);
819 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr);
820 ieee80211_mps_sta_status_update(sta);
821 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode);
822 return changed;
823 }
824
825 /**
826 * mesh_plink_fsm - step @sta MPM based on @event
827 *
828 * @sdata: interface
829 * @sta: mesh neighbor
830 * @event: peering event
831 *
832 * Return: changed MBSS flags
833 */
834 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata,
835 struct sta_info *sta, enum plink_event event)
836 {
837 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
838 enum ieee80211_self_protected_actioncode action = 0;
839 u32 changed = 0;
840 bool flush = false;
841
842 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr,
843 mplstates[sta->mesh->plink_state], mplevents[event]);
844
845 spin_lock_bh(&sta->mesh->plink_lock);
846 switch (sta->mesh->plink_state) {
847 case NL80211_PLINK_LISTEN:
848 switch (event) {
849 case CLS_ACPT:
850 mesh_plink_fsm_restart(sta);
851 break;
852 case OPN_ACPT:
853 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
854 sta->mesh->llid = mesh_get_new_llid(sdata);
855 mesh_plink_timer_set(sta,
856 mshcfg->dot11MeshRetryTimeout);
857
858 /* set the non-peer mode to active during peering */
859 changed |= ieee80211_mps_local_status_update(sdata);
860 action = WLAN_SP_MESH_PEERING_OPEN;
861 break;
862 default:
863 break;
864 }
865 break;
866 case NL80211_PLINK_OPN_SNT:
867 switch (event) {
868 case OPN_RJCT:
869 case CNF_RJCT:
870 case CLS_ACPT:
871 mesh_plink_close(sdata, sta, event);
872 action = WLAN_SP_MESH_PEERING_CLOSE;
873 break;
874 case OPN_ACPT:
875 /* retry timer is left untouched */
876 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
877 action = WLAN_SP_MESH_PEERING_CONFIRM;
878 break;
879 case CNF_ACPT:
880 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD;
881 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout);
882 break;
883 default:
884 break;
885 }
886 break;
887 case NL80211_PLINK_OPN_RCVD:
888 switch (event) {
889 case OPN_RJCT:
890 case CNF_RJCT:
891 case CLS_ACPT:
892 mesh_plink_close(sdata, sta, event);
893 action = WLAN_SP_MESH_PEERING_CLOSE;
894 break;
895 case OPN_ACPT:
896 action = WLAN_SP_MESH_PEERING_CONFIRM;
897 break;
898 case CNF_ACPT:
899 changed |= mesh_plink_establish(sdata, sta);
900 break;
901 default:
902 break;
903 }
904 break;
905 case NL80211_PLINK_CNF_RCVD:
906 switch (event) {
907 case OPN_RJCT:
908 case CNF_RJCT:
909 case CLS_ACPT:
910 mesh_plink_close(sdata, sta, event);
911 action = WLAN_SP_MESH_PEERING_CLOSE;
912 break;
913 case OPN_ACPT:
914 changed |= mesh_plink_establish(sdata, sta);
915 action = WLAN_SP_MESH_PEERING_CONFIRM;
916 break;
917 default:
918 break;
919 }
920 break;
921 case NL80211_PLINK_ESTAB:
922 switch (event) {
923 case CLS_ACPT:
924 changed |= __mesh_plink_deactivate(sta);
925 changed |= mesh_set_ht_prot_mode(sdata);
926 changed |= mesh_set_short_slot_time(sdata);
927 mesh_plink_close(sdata, sta, event);
928 action = WLAN_SP_MESH_PEERING_CLOSE;
929 flush = true;
930 break;
931 case OPN_ACPT:
932 action = WLAN_SP_MESH_PEERING_CONFIRM;
933 break;
934 default:
935 break;
936 }
937 break;
938 case NL80211_PLINK_HOLDING:
939 switch (event) {
940 case CLS_ACPT:
941 del_timer(&sta->mesh->plink_timer);
942 mesh_plink_fsm_restart(sta);
943 break;
944 case OPN_ACPT:
945 case CNF_ACPT:
946 case OPN_RJCT:
947 case CNF_RJCT:
948 action = WLAN_SP_MESH_PEERING_CLOSE;
949 break;
950 default:
951 break;
952 }
953 break;
954 default:
955 /* should not get here, PLINK_BLOCKED is dealt with at the
956 * beginning of the function
957 */
958 break;
959 }
960 spin_unlock_bh(&sta->mesh->plink_lock);
961 if (flush)
962 mesh_path_flush_by_nexthop(sta);
963 if (action) {
964 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
965 sta->mesh->llid, sta->mesh->plid,
966 sta->mesh->reason);
967
968 /* also send confirm in open case */
969 if (action == WLAN_SP_MESH_PEERING_OPEN) {
970 mesh_plink_frame_tx(sdata, sta,
971 WLAN_SP_MESH_PEERING_CONFIRM,
972 sta->sta.addr, sta->mesh->llid,
973 sta->mesh->plid, 0);
974 }
975 }
976
977 return changed;
978 }
979
980 /*
981 * mesh_plink_get_event - get correct MPM event
982 *
983 * @sdata: interface
984 * @sta: peer, leave NULL if processing a frame from a new suitable peer
985 * @elems: peering management IEs
986 * @ftype: frame type
987 * @llid: peer's peer link ID
988 * @plid: peer's local link ID
989 *
990 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as
991 * an error.
992 */
993 static enum plink_event
994 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata,
995 struct sta_info *sta,
996 struct ieee802_11_elems *elems,
997 enum ieee80211_self_protected_actioncode ftype,
998 u16 llid, u16 plid)
999 {
1000 enum plink_event event = PLINK_UNDEFINED;
1001 u8 ie_len = elems->peering_len;
1002 bool matches_local;
1003
1004 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE ||
1005 mesh_matches_local(sdata, elems));
1006
1007 /* deny open request from non-matching peer */
1008 if (!matches_local && !sta) {
1009 event = OPN_RJCT;
1010 goto out;
1011 }
1012
1013 if (!sta) {
1014 if (ftype != WLAN_SP_MESH_PEERING_OPEN) {
1015 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
1016 goto out;
1017 }
1018 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
1019 if (!mesh_plink_free_count(sdata)) {
1020 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
1021 goto out;
1022 }
1023
1024 /* new matching peer */
1025 event = OPN_ACPT;
1026 goto out;
1027 } else {
1028 if (!test_sta_flag(sta, WLAN_STA_AUTH)) {
1029 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
1030 goto out;
1031 }
1032 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED)
1033 goto out;
1034 }
1035
1036 switch (ftype) {
1037 case WLAN_SP_MESH_PEERING_OPEN:
1038 if (!matches_local)
1039 event = OPN_RJCT;
1040 if (!mesh_plink_free_count(sdata) ||
1041 (sta->mesh->plid && sta->mesh->plid != plid))
1042 event = OPN_IGNR;
1043 else
1044 event = OPN_ACPT;
1045 break;
1046 case WLAN_SP_MESH_PEERING_CONFIRM:
1047 if (!matches_local)
1048 event = CNF_RJCT;
1049 if (!mesh_plink_free_count(sdata) ||
1050 sta->mesh->llid != llid ||
1051 (sta->mesh->plid && sta->mesh->plid != plid))
1052 event = CNF_IGNR;
1053 else
1054 event = CNF_ACPT;
1055 break;
1056 case WLAN_SP_MESH_PEERING_CLOSE:
1057 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
1058 /* Do not check for llid or plid. This does not
1059 * follow the standard but since multiple plinks
1060 * per sta are not supported, it is necessary in
1061 * order to avoid a livelock when MP A sees an
1062 * establish peer link to MP B but MP B does not
1063 * see it. This can be caused by a timeout in
1064 * B's peer link establishment or B beign
1065 * restarted.
1066 */
1067 event = CLS_ACPT;
1068 else if (sta->mesh->plid != plid)
1069 event = CLS_IGNR;
1070 else if (ie_len == 8 && sta->mesh->llid != llid)
1071 event = CLS_IGNR;
1072 else
1073 event = CLS_ACPT;
1074 break;
1075 default:
1076 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
1077 break;
1078 }
1079
1080 out:
1081 return event;
1082 }
1083
1084 static void
1085 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
1086 struct ieee80211_mgmt *mgmt,
1087 struct ieee802_11_elems *elems,
1088 struct ieee80211_rx_status *rx_status)
1089 {
1090
1091 struct sta_info *sta;
1092 enum plink_event event;
1093 enum ieee80211_self_protected_actioncode ftype;
1094 u32 changed = 0;
1095 u8 ie_len = elems->peering_len;
1096 u16 plid, llid = 0;
1097
1098 if (!elems->peering) {
1099 mpl_dbg(sdata,
1100 "Mesh plink: missing necessary peer link ie\n");
1101 return;
1102 }
1103
1104 if (elems->rsn_len &&
1105 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
1106 mpl_dbg(sdata,
1107 "Mesh plink: can't establish link with secure peer\n");
1108 return;
1109 }
1110
1111 ftype = mgmt->u.action.u.self_prot.action_code;
1112 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
1113 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
1114 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
1115 && ie_len != 8)) {
1116 mpl_dbg(sdata,
1117 "Mesh plink: incorrect plink ie length %d %d\n",
1118 ftype, ie_len);
1119 return;
1120 }
1121
1122 if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
1123 (!elems->mesh_id || !elems->mesh_config)) {
1124 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
1125 return;
1126 }
1127 /* Note the lines below are correct, the llid in the frame is the plid
1128 * from the point of view of this host.
1129 */
1130 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering));
1131 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
1132 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
1133 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering));
1134
1135 /* WARNING: Only for sta pointer, is dropped & re-acquired */
1136 rcu_read_lock();
1137
1138 sta = sta_info_get(sdata, mgmt->sa);
1139
1140 if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
1141 !rssi_threshold_check(sdata, sta)) {
1142 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
1143 mgmt->sa);
1144 goto unlock_rcu;
1145 }
1146
1147 /* Now we will figure out the appropriate event... */
1148 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid);
1149
1150 if (event == OPN_ACPT) {
1151 rcu_read_unlock();
1152 /* allocate sta entry if necessary and update info */
1153 sta = mesh_sta_info_get(sdata, mgmt->sa, elems, rx_status);
1154 if (!sta) {
1155 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
1156 goto unlock_rcu;
1157 }
1158 sta->mesh->plid = plid;
1159 } else if (!sta && event == OPN_RJCT) {
1160 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE,
1161 mgmt->sa, 0, plid,
1162 WLAN_REASON_MESH_CONFIG);
1163 goto unlock_rcu;
1164 } else if (!sta || event == PLINK_UNDEFINED) {
1165 /* something went wrong */
1166 goto unlock_rcu;
1167 }
1168
1169 if (event == CNF_ACPT) {
1170 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */
1171 if (!sta->mesh->plid)
1172 sta->mesh->plid = plid;
1173
1174 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt));
1175 }
1176
1177 changed |= mesh_plink_fsm(sdata, sta, event);
1178
1179 unlock_rcu:
1180 rcu_read_unlock();
1181
1182 if (changed)
1183 ieee80211_mbss_info_change_notify(sdata, changed);
1184 }
1185
1186 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
1187 struct ieee80211_mgmt *mgmt, size_t len,
1188 struct ieee80211_rx_status *rx_status)
1189 {
1190 struct ieee802_11_elems elems;
1191 size_t baselen;
1192 u8 *baseaddr;
1193
1194 /* need action_code, aux */
1195 if (len < IEEE80211_MIN_ACTION_SIZE + 3)
1196 return;
1197
1198 if (sdata->u.mesh.user_mpm)
1199 /* userspace must register for these */
1200 return;
1201
1202 if (is_multicast_ether_addr(mgmt->da)) {
1203 mpl_dbg(sdata,
1204 "Mesh plink: ignore frame from multicast address\n");
1205 return;
1206 }
1207
1208 baseaddr = mgmt->u.action.u.self_prot.variable;
1209 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
1210 if (mgmt->u.action.u.self_prot.action_code ==
1211 WLAN_SP_MESH_PEERING_CONFIRM) {
1212 baseaddr += 4;
1213 baselen += 4;
1214
1215 if (baselen > len)
1216 return;
1217 }
1218 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems,
1219 mgmt->bssid, NULL);
1220 mesh_process_plink_frame(sdata, mgmt, &elems, rx_status);
1221 }
Linux with added FPC-III support