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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2008, 2009 open80211s Ltd.
4 * Copyright (C) 2019 Intel Corporation
5 * Author: Luis Carlos Cobo <luisca@cozybit.com>
6 */
7#include <linux/gfp.h>
8#include <linux/kernel.h>
9#include <linux/random.h>
10#include <linux/rculist.h>
11
12#include "ieee80211_i.h"
13#include "rate.h"
14#include "mesh.h"
15
16#define PLINK_CNF_AID(mgmt) ((mgmt)->u.action.u.self_prot.variable + 2)
17#define PLINK_GET_LLID(p) (p + 2)
18#define PLINK_GET_PLID(p) (p + 4)
19
20#define mod_plink_timer(s, t) (mod_timer(&s->mesh->plink_timer, \
21 jiffies + msecs_to_jiffies(t)))
22
23enum plink_event {
24 PLINK_UNDEFINED,
25 OPN_ACPT,
26 OPN_RJCT,
27 OPN_IGNR,
28 CNF_ACPT,
29 CNF_RJCT,
30 CNF_IGNR,
31 CLS_ACPT,
32 CLS_IGNR
33};
34
35static const char * const mplstates[] = {
36 [NL80211_PLINK_LISTEN] = "LISTEN",
37 [NL80211_PLINK_OPN_SNT] = "OPN-SNT",
38 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
39 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
40 [NL80211_PLINK_ESTAB] = "ESTAB",
41 [NL80211_PLINK_HOLDING] = "HOLDING",
42 [NL80211_PLINK_BLOCKED] = "BLOCKED"
43};
44
45static const char * const mplevents[] = {
46 [PLINK_UNDEFINED] = "NONE",
47 [OPN_ACPT] = "OPN_ACPT",
48 [OPN_RJCT] = "OPN_RJCT",
49 [OPN_IGNR] = "OPN_IGNR",
50 [CNF_ACPT] = "CNF_ACPT",
51 [CNF_RJCT] = "CNF_RJCT",
52 [CNF_IGNR] = "CNF_IGNR",
53 [CLS_ACPT] = "CLS_ACPT",
54 [CLS_IGNR] = "CLS_IGNR"
55};
56
57/* We only need a valid sta if user configured a minimum rssi_threshold. */
58static bool rssi_threshold_check(struct ieee80211_sub_if_data *sdata,
59 struct sta_info *sta)
60{
61 s32 rssi_threshold = sdata->u.mesh.mshcfg.rssi_threshold;
62 return rssi_threshold == 0 ||
63 (sta &&
64 (s8)-ewma_signal_read(&sta->rx_stats_avg.signal) >
65 rssi_threshold);
66}
67
68/**
69 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
70 *
71 * @sta: mesh peer link to restart
72 *
73 * Locking: this function must be called holding sta->mesh->plink_lock
74 */
75static inline void mesh_plink_fsm_restart(struct sta_info *sta)
76{
77 lockdep_assert_held(&sta->mesh->plink_lock);
78 sta->mesh->plink_state = NL80211_PLINK_LISTEN;
79 sta->mesh->llid = sta->mesh->plid = sta->mesh->reason = 0;
80 sta->mesh->plink_retries = 0;
81}
82
83/*
84 * mesh_set_short_slot_time - enable / disable ERP short slot time.
85 *
86 * The standard indirectly mandates mesh STAs to turn off short slot time by
87 * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we
88 * can't be sneaky about it. Enable short slot time if all mesh STAs in the
89 * MBSS support ERP rates.
90 *
91 * Returns BSS_CHANGED_ERP_SLOT or 0 for no change.
92 */
93static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata)
94{
95 struct ieee80211_local *local = sdata->local;
96 struct ieee80211_supported_band *sband;
97 struct sta_info *sta;
98 u32 erp_rates = 0, changed = 0;
99 int i;
100 bool short_slot = false;
101
102 sband = ieee80211_get_sband(sdata);
103 if (!sband)
104 return changed;
105
106 if (sband->band == NL80211_BAND_5GHZ) {
107 /* (IEEE 802.11-2012 19.4.5) */
108 short_slot = true;
109 goto out;
110 } else if (sband->band != NL80211_BAND_2GHZ) {
111 goto out;
112 }
113
114 for (i = 0; i < sband->n_bitrates; i++)
115 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)
116 erp_rates |= BIT(i);
117
118 if (!erp_rates)
119 goto out;
120
121 rcu_read_lock();
122 list_for_each_entry_rcu(sta, &local->sta_list, list) {
123 if (sdata != sta->sdata ||
124 sta->mesh->plink_state != NL80211_PLINK_ESTAB)
125 continue;
126
127 short_slot = false;
128 if (erp_rates & sta->sta.supp_rates[sband->band])
129 short_slot = true;
130 else
131 break;
132 }
133 rcu_read_unlock();
134
135out:
136 if (sdata->vif.bss_conf.use_short_slot != short_slot) {
137 sdata->vif.bss_conf.use_short_slot = short_slot;
138 changed = BSS_CHANGED_ERP_SLOT;
139 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n",
140 sdata->vif.addr, short_slot);
141 }
142 return changed;
143}
144
145/**
146 * mesh_set_ht_prot_mode - set correct HT protection mode
147 *
148 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
149 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
150 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
151 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode
152 * is selected if all peers in our 20/40MHz MBSS support HT and atleast one
153 * HT20 peer is present. Otherwise no-protection mode is selected.
154 */
155static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
156{
157 struct ieee80211_local *local = sdata->local;
158 struct sta_info *sta;
159 u16 ht_opmode;
160 bool non_ht_sta = false, ht20_sta = false;
161
162 switch (sdata->vif.bss_conf.chandef.width) {
163 case NL80211_CHAN_WIDTH_20_NOHT:
164 case NL80211_CHAN_WIDTH_5:
165 case NL80211_CHAN_WIDTH_10:
166 return 0;
167 default:
168 break;
169 }
170
171 rcu_read_lock();
172 list_for_each_entry_rcu(sta, &local->sta_list, list) {
173 if (sdata != sta->sdata ||
174 sta->mesh->plink_state != NL80211_PLINK_ESTAB)
175 continue;
176
177 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20)
178 continue;
179
180 if (!sta->sta.ht_cap.ht_supported) {
181 mpl_dbg(sdata, "nonHT sta (%pM) is present\n",
182 sta->sta.addr);
183 non_ht_sta = true;
184 break;
185 }
186
187 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr);
188 ht20_sta = true;
189 }
190 rcu_read_unlock();
191
192 if (non_ht_sta)
193 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
194 else if (ht20_sta &&
195 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20)
196 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
197 else
198 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
199
200 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode)
201 return 0;
202
203 sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
204 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
205 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode);
206 return BSS_CHANGED_HT;
207}
208
209static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
210 struct sta_info *sta,
211 enum ieee80211_self_protected_actioncode action,
212 u8 *da, u16 llid, u16 plid, u16 reason)
213{
214 struct ieee80211_local *local = sdata->local;
215 struct sk_buff *skb;
216 struct ieee80211_tx_info *info;
217 struct ieee80211_mgmt *mgmt;
218 bool include_plid = false;
219 u16 peering_proto = 0;
220 u8 *pos, ie_len = 4;
221 u8 ie_len_he_cap;
222 int hdr_len = offsetofend(struct ieee80211_mgmt, u.action.u.self_prot);
223 int err = -ENOMEM;
224
225 ie_len_he_cap = ieee80211_ie_len_he_cap(sdata,
226 NL80211_IFTYPE_MESH_POINT);
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 ie_len_he_cap +
240 2 + 1 + sizeof(struct ieee80211_he_operation) +
241 sizeof(struct ieee80211_he_6ghz_oper) +
242 2 + 1 + sizeof(struct ieee80211_he_6ghz_capa) +
243 2 + 8 + /* peering IE */
244 sdata->u.mesh.ie_len);
245 if (!skb)
246 return err;
247 info = IEEE80211_SKB_CB(skb);
248 skb_reserve(skb, local->tx_headroom);
249 mgmt = skb_put_zero(skb, hdr_len);
250 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
251 IEEE80211_STYPE_ACTION);
252 memcpy(mgmt->da, da, ETH_ALEN);
253 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
254 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
255 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
256 mgmt->u.action.u.self_prot.action_code = action;
257
258 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
259 struct ieee80211_supported_band *sband;
260 enum nl80211_band band;
261
262 sband = ieee80211_get_sband(sdata);
263 if (!sband) {
264 err = -EINVAL;
265 goto free;
266 }
267 band = sband->band;
268
269 /* capability info */
270 pos = skb_put_zero(skb, 2);
271 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
272 /* AID */
273 pos = skb_put(skb, 2);
274 put_unaligned_le16(sta->sta.aid, pos);
275 }
276 if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
277 ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
278 mesh_add_rsn_ie(sdata, skb) ||
279 mesh_add_meshid_ie(sdata, skb) ||
280 mesh_add_meshconf_ie(sdata, skb))
281 goto free;
282 } else { /* WLAN_SP_MESH_PEERING_CLOSE */
283 info->flags |= IEEE80211_TX_CTL_NO_ACK;
284 if (mesh_add_meshid_ie(sdata, skb))
285 goto free;
286 }
287
288 /* Add Mesh Peering Management element */
289 switch (action) {
290 case WLAN_SP_MESH_PEERING_OPEN:
291 break;
292 case WLAN_SP_MESH_PEERING_CONFIRM:
293 ie_len += 2;
294 include_plid = true;
295 break;
296 case WLAN_SP_MESH_PEERING_CLOSE:
297 if (plid) {
298 ie_len += 2;
299 include_plid = true;
300 }
301 ie_len += 2; /* reason code */
302 break;
303 default:
304 err = -EINVAL;
305 goto free;
306 }
307
308 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
309 goto free;
310
311 pos = skb_put(skb, 2 + ie_len);
312 *pos++ = WLAN_EID_PEER_MGMT;
313 *pos++ = ie_len;
314 memcpy(pos, &peering_proto, 2);
315 pos += 2;
316 put_unaligned_le16(llid, pos);
317 pos += 2;
318 if (include_plid) {
319 put_unaligned_le16(plid, pos);
320 pos += 2;
321 }
322 if (action == WLAN_SP_MESH_PEERING_CLOSE) {
323 put_unaligned_le16(reason, pos);
324 pos += 2;
325 }
326
327 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
328 if (mesh_add_ht_cap_ie(sdata, skb) ||
329 mesh_add_ht_oper_ie(sdata, skb) ||
330 mesh_add_vht_cap_ie(sdata, skb) ||
331 mesh_add_vht_oper_ie(sdata, skb) ||
332 mesh_add_he_cap_ie(sdata, skb, ie_len_he_cap) ||
333 mesh_add_he_oper_ie(sdata, skb) ||
334 mesh_add_he_6ghz_cap_ie(sdata, skb))
335 goto free;
336 }
337
338 if (mesh_add_vendor_ies(sdata, skb))
339 goto free;
340
341 ieee80211_tx_skb(sdata, skb);
342 return 0;
343free:
344 kfree_skb(skb);
345 return err;
346}
347
348/**
349 * __mesh_plink_deactivate - deactivate mesh peer link
350 *
351 * @sta: mesh peer link to deactivate
352 *
353 * Mesh paths with this peer as next hop should be flushed
354 * by the caller outside of plink_lock.
355 *
356 * Returns beacon changed flag if the beacon content changed.
357 *
358 * Locking: the caller must hold sta->mesh->plink_lock
359 */
360static u32 __mesh_plink_deactivate(struct sta_info *sta)
361{
362 struct ieee80211_sub_if_data *sdata = sta->sdata;
363 u32 changed = 0;
364
365 lockdep_assert_held(&sta->mesh->plink_lock);
366
367 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
368 changed = mesh_plink_dec_estab_count(sdata);
369 sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
370
371 ieee80211_mps_sta_status_update(sta);
372 changed |= ieee80211_mps_set_sta_local_pm(sta,
373 NL80211_MESH_POWER_UNKNOWN);
374
375 return changed;
376}
377
378/**
379 * mesh_plink_deactivate - deactivate mesh peer link
380 *
381 * @sta: mesh peer link to deactivate
382 *
383 * All mesh paths with this peer as next hop will be flushed
384 */
385u32 mesh_plink_deactivate(struct sta_info *sta)
386{
387 struct ieee80211_sub_if_data *sdata = sta->sdata;
388 u32 changed;
389
390 spin_lock_bh(&sta->mesh->plink_lock);
391 changed = __mesh_plink_deactivate(sta);
392
393 if (!sdata->u.mesh.user_mpm) {
394 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED;
395 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE,
396 sta->sta.addr, sta->mesh->llid,
397 sta->mesh->plid, sta->mesh->reason);
398 }
399 spin_unlock_bh(&sta->mesh->plink_lock);
400 if (!sdata->u.mesh.user_mpm)
401 del_timer_sync(&sta->mesh->plink_timer);
402 mesh_path_flush_by_nexthop(sta);
403
404 /* make sure no readers can access nexthop sta from here on */
405 synchronize_net();
406
407 return changed;
408}
409
410static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
411 struct sta_info *sta,
412 struct ieee802_11_elems *elems)
413{
414 struct ieee80211_local *local = sdata->local;
415 struct ieee80211_supported_band *sband;
416 u32 rates, basic_rates = 0, changed = 0;
417 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth;
418
419 sband = ieee80211_get_sband(sdata);
420 if (!sband)
421 return;
422
423 rates = ieee80211_sta_get_rates(sdata, elems, sband->band,
424 &basic_rates);
425
426 spin_lock_bh(&sta->mesh->plink_lock);
427 sta->rx_stats.last_rx = jiffies;
428
429 /* rates and capabilities don't change during peering */
430 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB &&
431 sta->mesh->processed_beacon)
432 goto out;
433 sta->mesh->processed_beacon = true;
434
435 if (sta->sta.supp_rates[sband->band] != rates)
436 changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
437 sta->sta.supp_rates[sband->band] = rates;
438
439 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
440 elems->ht_cap_elem, sta))
441 changed |= IEEE80211_RC_BW_CHANGED;
442
443 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
444 elems->vht_cap_elem, sta);
445
446 ieee80211_he_cap_ie_to_sta_he_cap(sdata, sband, elems->he_cap,
447 elems->he_cap_len,
448 elems->he_6ghz_capa,
449 sta);
450
451 if (bw != sta->sta.bandwidth)
452 changed |= IEEE80211_RC_BW_CHANGED;
453
454 /* HT peer is operating 20MHz-only */
455 if (elems->ht_operation &&
456 !(elems->ht_operation->ht_param &
457 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
458 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20)
459 changed |= IEEE80211_RC_BW_CHANGED;
460 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20;
461 }
462
463 if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
464 rate_control_rate_init(sta);
465 else
466 rate_control_rate_update(local, sband, sta, changed);
467out:
468 spin_unlock_bh(&sta->mesh->plink_lock);
469}
470
471static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata)
472{
473 struct sta_info *sta;
474 unsigned long *aid_map;
475 int aid;
476
477 aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1),
478 sizeof(*aid_map), GFP_KERNEL);
479 if (!aid_map)
480 return -ENOMEM;
481
482 /* reserve aid 0 for mcast indication */
483 __set_bit(0, aid_map);
484
485 rcu_read_lock();
486 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list)
487 __set_bit(sta->sta.aid, aid_map);
488 rcu_read_unlock();
489
490 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1);
491 kfree(aid_map);
492
493 if (aid > IEEE80211_MAX_AID)
494 return -ENOBUFS;
495
496 return aid;
497}
498
499static struct sta_info *
500__mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
501{
502 struct sta_info *sta;
503 int aid;
504
505 if (sdata->local->num_sta >= MESH_MAX_PLINKS)
506 return NULL;
507
508 aid = mesh_allocate_aid(sdata);
509 if (aid < 0)
510 return NULL;
511
512 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
513 if (!sta)
514 return NULL;
515
516 sta->mesh->plink_state = NL80211_PLINK_LISTEN;
517 sta->sta.wme = true;
518 sta->sta.aid = aid;
519
520 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
521 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
522 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
523
524 return sta;
525}
526
527static struct sta_info *
528mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
529 struct ieee802_11_elems *elems,
530 struct ieee80211_rx_status *rx_status)
531{
532 struct sta_info *sta = NULL;
533
534 /* Userspace handles station allocation */
535 if (sdata->u.mesh.user_mpm ||
536 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) {
537 if (mesh_peer_accepts_plinks(elems) &&
538 mesh_plink_availables(sdata)) {
539 int sig = 0;
540
541 if (ieee80211_hw_check(&sdata->local->hw, SIGNAL_DBM))
542 sig = rx_status->signal;
543
544 cfg80211_notify_new_peer_candidate(sdata->dev, addr,
545 elems->ie_start,
546 elems->total_len,
547 sig, GFP_KERNEL);
548 }
549 } else
550 sta = __mesh_sta_info_alloc(sdata, addr);
551
552 return sta;
553}
554
555/*
556 * mesh_sta_info_get - return mesh sta info entry for @addr.
557 *
558 * @sdata: local meshif
559 * @addr: peer's address
560 * @elems: IEs from beacon or mesh peering frame.
561 * @rx_status: rx status for the frame for signal reporting
562 *
563 * Return existing or newly allocated sta_info under RCU read lock.
564 * (re)initialize with given IEs.
565 */
566static struct sta_info *
567mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
568 u8 *addr, struct ieee802_11_elems *elems,
569 struct ieee80211_rx_status *rx_status) __acquires(RCU)
570{
571 struct sta_info *sta = NULL;
572
573 rcu_read_lock();
574 sta = sta_info_get(sdata, addr);
575 if (sta) {
576 mesh_sta_info_init(sdata, sta, elems);
577 } else {
578 rcu_read_unlock();
579 /* can't run atomic */
580 sta = mesh_sta_info_alloc(sdata, addr, elems, rx_status);
581 if (!sta) {
582 rcu_read_lock();
583 return NULL;
584 }
585
586 mesh_sta_info_init(sdata, sta, elems);
587
588 if (sta_info_insert_rcu(sta))
589 return NULL;
590 }
591
592 return sta;
593}
594
595/*
596 * mesh_neighbour_update - update or initialize new mesh neighbor.
597 *
598 * @sdata: local meshif
599 * @addr: peer's address
600 * @elems: IEs from beacon or mesh peering frame
601 * @rx_status: rx status for the frame for signal reporting
602 *
603 * Initiates peering if appropriate.
604 */
605void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
606 u8 *hw_addr,
607 struct ieee802_11_elems *elems,
608 struct ieee80211_rx_status *rx_status)
609{
610 struct sta_info *sta;
611 u32 changed = 0;
612
613 sta = mesh_sta_info_get(sdata, hw_addr, elems, rx_status);
614 if (!sta)
615 goto out;
616
617 sta->mesh->connected_to_gate = elems->mesh_config->meshconf_form &
618 IEEE80211_MESHCONF_FORM_CONNECTED_TO_GATE;
619
620 if (mesh_peer_accepts_plinks(elems) &&
621 sta->mesh->plink_state == NL80211_PLINK_LISTEN &&
622 sdata->u.mesh.accepting_plinks &&
623 sdata->u.mesh.mshcfg.auto_open_plinks &&
624 rssi_threshold_check(sdata, sta))
625 changed = mesh_plink_open(sta);
626
627 ieee80211_mps_frame_release(sta, elems);
628out:
629 rcu_read_unlock();
630 ieee80211_mbss_info_change_notify(sdata, changed);
631}
632
633void mesh_plink_timer(struct timer_list *t)
634{
635 struct mesh_sta *mesh = from_timer(mesh, t, plink_timer);
636 struct sta_info *sta;
637 u16 reason = 0;
638 struct ieee80211_sub_if_data *sdata;
639 struct mesh_config *mshcfg;
640 enum ieee80211_self_protected_actioncode action = 0;
641
642 /*
643 * This STA is valid because sta_info_destroy() will
644 * del_timer_sync() this timer after having made sure
645 * it cannot be readded (by deleting the plink.)
646 */
647 sta = mesh->plink_sta;
648
649 if (sta->sdata->local->quiescing)
650 return;
651
652 spin_lock_bh(&sta->mesh->plink_lock);
653
654 /* If a timer fires just before a state transition on another CPU,
655 * we may have already extended the timeout and changed state by the
656 * time we've acquired the lock and arrived here. In that case,
657 * skip this timer and wait for the new one.
658 */
659 if (time_before(jiffies, sta->mesh->plink_timer.expires)) {
660 mpl_dbg(sta->sdata,
661 "Ignoring timer for %pM in state %s (timer adjusted)",
662 sta->sta.addr, mplstates[sta->mesh->plink_state]);
663 spin_unlock_bh(&sta->mesh->plink_lock);
664 return;
665 }
666
667 /* del_timer() and handler may race when entering these states */
668 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN ||
669 sta->mesh->plink_state == NL80211_PLINK_ESTAB) {
670 mpl_dbg(sta->sdata,
671 "Ignoring timer for %pM in state %s (timer deleted)",
672 sta->sta.addr, mplstates[sta->mesh->plink_state]);
673 spin_unlock_bh(&sta->mesh->plink_lock);
674 return;
675 }
676
677 mpl_dbg(sta->sdata,
678 "Mesh plink timer for %pM fired on state %s\n",
679 sta->sta.addr, mplstates[sta->mesh->plink_state]);
680 sdata = sta->sdata;
681 mshcfg = &sdata->u.mesh.mshcfg;
682
683 switch (sta->mesh->plink_state) {
684 case NL80211_PLINK_OPN_RCVD:
685 case NL80211_PLINK_OPN_SNT:
686 /* retry timer */
687 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) {
688 u32 rand;
689 mpl_dbg(sta->sdata,
690 "Mesh plink for %pM (retry, timeout): %d %d\n",
691 sta->sta.addr, sta->mesh->plink_retries,
692 sta->mesh->plink_timeout);
693 get_random_bytes(&rand, sizeof(u32));
694 sta->mesh->plink_timeout = sta->mesh->plink_timeout +
695 rand % sta->mesh->plink_timeout;
696 ++sta->mesh->plink_retries;
697 mod_plink_timer(sta, sta->mesh->plink_timeout);
698 action = WLAN_SP_MESH_PEERING_OPEN;
699 break;
700 }
701 reason = WLAN_REASON_MESH_MAX_RETRIES;
702 fallthrough;
703 case NL80211_PLINK_CNF_RCVD:
704 /* confirm timer */
705 if (!reason)
706 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT;
707 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
708 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
709 action = WLAN_SP_MESH_PEERING_CLOSE;
710 break;
711 case NL80211_PLINK_HOLDING:
712 /* holding timer */
713 del_timer(&sta->mesh->plink_timer);
714 mesh_plink_fsm_restart(sta);
715 break;
716 default:
717 break;
718 }
719 spin_unlock_bh(&sta->mesh->plink_lock);
720 if (action)
721 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
722 sta->mesh->llid, sta->mesh->plid, reason);
723}
724
725static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout)
726{
727 sta->mesh->plink_timeout = timeout;
728 mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout));
729}
730
731static bool llid_in_use(struct ieee80211_sub_if_data *sdata,
732 u16 llid)
733{
734 struct ieee80211_local *local = sdata->local;
735 bool in_use = false;
736 struct sta_info *sta;
737
738 rcu_read_lock();
739 list_for_each_entry_rcu(sta, &local->sta_list, list) {
740 if (sdata != sta->sdata)
741 continue;
742
743 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) {
744 in_use = true;
745 break;
746 }
747 }
748 rcu_read_unlock();
749
750 return in_use;
751}
752
753static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata)
754{
755 u16 llid;
756
757 do {
758 get_random_bytes(&llid, sizeof(llid));
759 } while (llid_in_use(sdata, llid));
760
761 return llid;
762}
763
764u32 mesh_plink_open(struct sta_info *sta)
765{
766 struct ieee80211_sub_if_data *sdata = sta->sdata;
767 u32 changed;
768
769 if (!test_sta_flag(sta, WLAN_STA_AUTH))
770 return 0;
771
772 spin_lock_bh(&sta->mesh->plink_lock);
773 sta->mesh->llid = mesh_get_new_llid(sdata);
774 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN &&
775 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) {
776 spin_unlock_bh(&sta->mesh->plink_lock);
777 return 0;
778 }
779 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT;
780 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
781 spin_unlock_bh(&sta->mesh->plink_lock);
782 mpl_dbg(sdata,
783 "Mesh plink: starting establishment with %pM\n",
784 sta->sta.addr);
785
786 /* set the non-peer mode to active during peering */
787 changed = ieee80211_mps_local_status_update(sdata);
788
789 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN,
790 sta->sta.addr, sta->mesh->llid, 0, 0);
791 return changed;
792}
793
794u32 mesh_plink_block(struct sta_info *sta)
795{
796 u32 changed;
797
798 spin_lock_bh(&sta->mesh->plink_lock);
799 changed = __mesh_plink_deactivate(sta);
800 sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
801 spin_unlock_bh(&sta->mesh->plink_lock);
802 mesh_path_flush_by_nexthop(sta);
803
804 return changed;
805}
806
807static void mesh_plink_close(struct ieee80211_sub_if_data *sdata,
808 struct sta_info *sta,
809 enum plink_event event)
810{
811 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
812 u16 reason = (event == CLS_ACPT) ?
813 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG;
814
815 sta->mesh->reason = reason;
816 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
817 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
818}
819
820static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata,
821 struct sta_info *sta)
822{
823 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
824 u32 changed = 0;
825
826 del_timer(&sta->mesh->plink_timer);
827 sta->mesh->plink_state = NL80211_PLINK_ESTAB;
828 changed |= mesh_plink_inc_estab_count(sdata);
829 changed |= mesh_set_ht_prot_mode(sdata);
830 changed |= mesh_set_short_slot_time(sdata);
831 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr);
832 ieee80211_mps_sta_status_update(sta);
833 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode);
834 return changed;
835}
836
837/**
838 * mesh_plink_fsm - step @sta MPM based on @event
839 *
840 * @sdata: interface
841 * @sta: mesh neighbor
842 * @event: peering event
843 *
844 * Return: changed MBSS flags
845 */
846static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata,
847 struct sta_info *sta, enum plink_event event)
848{
849 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
850 enum ieee80211_self_protected_actioncode action = 0;
851 u32 changed = 0;
852 bool flush = false;
853
854 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr,
855 mplstates[sta->mesh->plink_state], mplevents[event]);
856
857 spin_lock_bh(&sta->mesh->plink_lock);
858 switch (sta->mesh->plink_state) {
859 case NL80211_PLINK_LISTEN:
860 switch (event) {
861 case CLS_ACPT:
862 mesh_plink_fsm_restart(sta);
863 break;
864 case OPN_ACPT:
865 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
866 sta->mesh->llid = mesh_get_new_llid(sdata);
867 mesh_plink_timer_set(sta,
868 mshcfg->dot11MeshRetryTimeout);
869
870 /* set the non-peer mode to active during peering */
871 changed |= ieee80211_mps_local_status_update(sdata);
872 action = WLAN_SP_MESH_PEERING_OPEN;
873 break;
874 default:
875 break;
876 }
877 break;
878 case NL80211_PLINK_OPN_SNT:
879 switch (event) {
880 case OPN_RJCT:
881 case CNF_RJCT:
882 case CLS_ACPT:
883 mesh_plink_close(sdata, sta, event);
884 action = WLAN_SP_MESH_PEERING_CLOSE;
885 break;
886 case OPN_ACPT:
887 /* retry timer is left untouched */
888 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
889 action = WLAN_SP_MESH_PEERING_CONFIRM;
890 break;
891 case CNF_ACPT:
892 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD;
893 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout);
894 break;
895 default:
896 break;
897 }
898 break;
899 case NL80211_PLINK_OPN_RCVD:
900 switch (event) {
901 case OPN_RJCT:
902 case CNF_RJCT:
903 case CLS_ACPT:
904 mesh_plink_close(sdata, sta, event);
905 action = WLAN_SP_MESH_PEERING_CLOSE;
906 break;
907 case OPN_ACPT:
908 action = WLAN_SP_MESH_PEERING_CONFIRM;
909 break;
910 case CNF_ACPT:
911 changed |= mesh_plink_establish(sdata, sta);
912 break;
913 default:
914 break;
915 }
916 break;
917 case NL80211_PLINK_CNF_RCVD:
918 switch (event) {
919 case OPN_RJCT:
920 case CNF_RJCT:
921 case CLS_ACPT:
922 mesh_plink_close(sdata, sta, event);
923 action = WLAN_SP_MESH_PEERING_CLOSE;
924 break;
925 case OPN_ACPT:
926 changed |= mesh_plink_establish(sdata, sta);
927 action = WLAN_SP_MESH_PEERING_CONFIRM;
928 break;
929 default:
930 break;
931 }
932 break;
933 case NL80211_PLINK_ESTAB:
934 switch (event) {
935 case CLS_ACPT:
936 changed |= __mesh_plink_deactivate(sta);
937 changed |= mesh_set_ht_prot_mode(sdata);
938 changed |= mesh_set_short_slot_time(sdata);
939 mesh_plink_close(sdata, sta, event);
940 action = WLAN_SP_MESH_PEERING_CLOSE;
941 flush = true;
942 break;
943 case OPN_ACPT:
944 action = WLAN_SP_MESH_PEERING_CONFIRM;
945 break;
946 default:
947 break;
948 }
949 break;
950 case NL80211_PLINK_HOLDING:
951 switch (event) {
952 case CLS_ACPT:
953 del_timer(&sta->mesh->plink_timer);
954 mesh_plink_fsm_restart(sta);
955 break;
956 case OPN_ACPT:
957 case CNF_ACPT:
958 case OPN_RJCT:
959 case CNF_RJCT:
960 action = WLAN_SP_MESH_PEERING_CLOSE;
961 break;
962 default:
963 break;
964 }
965 break;
966 default:
967 /* should not get here, PLINK_BLOCKED is dealt with at the
968 * beginning of the function
969 */
970 break;
971 }
972 spin_unlock_bh(&sta->mesh->plink_lock);
973 if (flush)
974 mesh_path_flush_by_nexthop(sta);
975 if (action) {
976 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
977 sta->mesh->llid, sta->mesh->plid,
978 sta->mesh->reason);
979
980 /* also send confirm in open case */
981 if (action == WLAN_SP_MESH_PEERING_OPEN) {
982 mesh_plink_frame_tx(sdata, sta,
983 WLAN_SP_MESH_PEERING_CONFIRM,
984 sta->sta.addr, sta->mesh->llid,
985 sta->mesh->plid, 0);
986 }
987 }
988
989 return changed;
990}
991
992/*
993 * mesh_plink_get_event - get correct MPM event
994 *
995 * @sdata: interface
996 * @sta: peer, leave NULL if processing a frame from a new suitable peer
997 * @elems: peering management IEs
998 * @ftype: frame type
999 * @llid: peer's peer link ID
1000 * @plid: peer's local link ID
1001 *
1002 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as
1003 * an error.
1004 */
1005static enum plink_event
1006mesh_plink_get_event(struct ieee80211_sub_if_data *sdata,
1007 struct sta_info *sta,
1008 struct ieee802_11_elems *elems,
1009 enum ieee80211_self_protected_actioncode ftype,
1010 u16 llid, u16 plid)
1011{
1012 enum plink_event event = PLINK_UNDEFINED;
1013 u8 ie_len = elems->peering_len;
1014 bool matches_local;
1015
1016 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE ||
1017 mesh_matches_local(sdata, elems));
1018
1019 /* deny open request from non-matching peer */
1020 if (!matches_local && !sta) {
1021 event = OPN_RJCT;
1022 goto out;
1023 }
1024
1025 if (!sta) {
1026 if (ftype != WLAN_SP_MESH_PEERING_OPEN) {
1027 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
1028 goto out;
1029 }
1030 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
1031 if (!mesh_plink_free_count(sdata)) {
1032 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
1033 goto out;
1034 }
1035
1036 /* new matching peer */
1037 event = OPN_ACPT;
1038 goto out;
1039 } else {
1040 if (!test_sta_flag(sta, WLAN_STA_AUTH)) {
1041 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
1042 goto out;
1043 }
1044 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED)
1045 goto out;
1046 }
1047
1048 switch (ftype) {
1049 case WLAN_SP_MESH_PEERING_OPEN:
1050 if (!matches_local)
1051 event = OPN_RJCT;
1052 if (!mesh_plink_free_count(sdata) ||
1053 (sta->mesh->plid && sta->mesh->plid != plid))
1054 event = OPN_IGNR;
1055 else
1056 event = OPN_ACPT;
1057 break;
1058 case WLAN_SP_MESH_PEERING_CONFIRM:
1059 if (!matches_local)
1060 event = CNF_RJCT;
1061 if (!mesh_plink_free_count(sdata) ||
1062 sta->mesh->llid != llid ||
1063 (sta->mesh->plid && sta->mesh->plid != plid))
1064 event = CNF_IGNR;
1065 else
1066 event = CNF_ACPT;
1067 break;
1068 case WLAN_SP_MESH_PEERING_CLOSE:
1069 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
1070 /* Do not check for llid or plid. This does not
1071 * follow the standard but since multiple plinks
1072 * per sta are not supported, it is necessary in
1073 * order to avoid a livelock when MP A sees an
1074 * establish peer link to MP B but MP B does not
1075 * see it. This can be caused by a timeout in
1076 * B's peer link establishment or B beign
1077 * restarted.
1078 */
1079 event = CLS_ACPT;
1080 else if (sta->mesh->plid != plid)
1081 event = CLS_IGNR;
1082 else if (ie_len == 8 && sta->mesh->llid != llid)
1083 event = CLS_IGNR;
1084 else
1085 event = CLS_ACPT;
1086 break;
1087 default:
1088 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
1089 break;
1090 }
1091
1092out:
1093 return event;
1094}
1095
1096static void
1097mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
1098 struct ieee80211_mgmt *mgmt,
1099 struct ieee802_11_elems *elems,
1100 struct ieee80211_rx_status *rx_status)
1101{
1102
1103 struct sta_info *sta;
1104 enum plink_event event;
1105 enum ieee80211_self_protected_actioncode ftype;
1106 u32 changed = 0;
1107 u8 ie_len = elems->peering_len;
1108 u16 plid, llid = 0;
1109
1110 if (!elems->peering) {
1111 mpl_dbg(sdata,
1112 "Mesh plink: missing necessary peer link ie\n");
1113 return;
1114 }
1115
1116 if (elems->rsn_len &&
1117 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
1118 mpl_dbg(sdata,
1119 "Mesh plink: can't establish link with secure peer\n");
1120 return;
1121 }
1122
1123 ftype = mgmt->u.action.u.self_prot.action_code;
1124 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
1125 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
1126 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
1127 && ie_len != 8)) {
1128 mpl_dbg(sdata,
1129 "Mesh plink: incorrect plink ie length %d %d\n",
1130 ftype, ie_len);
1131 return;
1132 }
1133
1134 if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
1135 (!elems->mesh_id || !elems->mesh_config)) {
1136 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
1137 return;
1138 }
1139 /* Note the lines below are correct, the llid in the frame is the plid
1140 * from the point of view of this host.
1141 */
1142 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering));
1143 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
1144 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
1145 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering));
1146
1147 /* WARNING: Only for sta pointer, is dropped & re-acquired */
1148 rcu_read_lock();
1149
1150 sta = sta_info_get(sdata, mgmt->sa);
1151
1152 if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
1153 !rssi_threshold_check(sdata, sta)) {
1154 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
1155 mgmt->sa);
1156 goto unlock_rcu;
1157 }
1158
1159 /* Now we will figure out the appropriate event... */
1160 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid);
1161
1162 if (event == OPN_ACPT) {
1163 rcu_read_unlock();
1164 /* allocate sta entry if necessary and update info */
1165 sta = mesh_sta_info_get(sdata, mgmt->sa, elems, rx_status);
1166 if (!sta) {
1167 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
1168 goto unlock_rcu;
1169 }
1170 sta->mesh->plid = plid;
1171 } else if (!sta && event == OPN_RJCT) {
1172 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE,
1173 mgmt->sa, 0, plid,
1174 WLAN_REASON_MESH_CONFIG);
1175 goto unlock_rcu;
1176 } else if (!sta || event == PLINK_UNDEFINED) {
1177 /* something went wrong */
1178 goto unlock_rcu;
1179 }
1180
1181 if (event == CNF_ACPT) {
1182 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */
1183 if (!sta->mesh->plid)
1184 sta->mesh->plid = plid;
1185
1186 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt));
1187 }
1188
1189 changed |= mesh_plink_fsm(sdata, sta, event);
1190
1191unlock_rcu:
1192 rcu_read_unlock();
1193
1194 if (changed)
1195 ieee80211_mbss_info_change_notify(sdata, changed);
1196}
1197
1198void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
1199 struct ieee80211_mgmt *mgmt, size_t len,
1200 struct ieee80211_rx_status *rx_status)
1201{
1202 struct ieee802_11_elems elems;
1203 size_t baselen;
1204 u8 *baseaddr;
1205
1206 /* need action_code, aux */
1207 if (len < IEEE80211_MIN_ACTION_SIZE + 3)
1208 return;
1209
1210 if (sdata->u.mesh.user_mpm)
1211 /* userspace must register for these */
1212 return;
1213
1214 if (is_multicast_ether_addr(mgmt->da)) {
1215 mpl_dbg(sdata,
1216 "Mesh plink: ignore frame from multicast address\n");
1217 return;
1218 }
1219
1220 baseaddr = mgmt->u.action.u.self_prot.variable;
1221 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
1222 if (mgmt->u.action.u.self_prot.action_code ==
1223 WLAN_SP_MESH_PEERING_CONFIRM) {
1224 baseaddr += 4;
1225 baselen += 4;
1226
1227 if (baselen > len)
1228 return;
1229 }
1230 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems,
1231 mgmt->bssid, NULL);
1232 mesh_process_plink_frame(sdata, mgmt, &elems, rx_status);
1233}
1/*
2 * Copyright (c) 2008, 2009 open80211s Ltd.
3 * Author: Luis Carlos Cobo <luisca@cozybit.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9#include <linux/gfp.h>
10#include <linux/kernel.h>
11#include <linux/random.h>
12#include "ieee80211_i.h"
13#include "rate.h"
14#include "mesh.h"
15
16#define PLINK_CNF_AID(mgmt) ((mgmt)->u.action.u.self_prot.variable + 2)
17#define PLINK_GET_LLID(p) (p + 2)
18#define PLINK_GET_PLID(p) (p + 4)
19
20#define mod_plink_timer(s, t) (mod_timer(&s->mesh->plink_timer, \
21 jiffies + msecs_to_jiffies(t)))
22
23enum plink_event {
24 PLINK_UNDEFINED,
25 OPN_ACPT,
26 OPN_RJCT,
27 OPN_IGNR,
28 CNF_ACPT,
29 CNF_RJCT,
30 CNF_IGNR,
31 CLS_ACPT,
32 CLS_IGNR
33};
34
35static const char * const mplstates[] = {
36 [NL80211_PLINK_LISTEN] = "LISTEN",
37 [NL80211_PLINK_OPN_SNT] = "OPN-SNT",
38 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
39 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
40 [NL80211_PLINK_ESTAB] = "ESTAB",
41 [NL80211_PLINK_HOLDING] = "HOLDING",
42 [NL80211_PLINK_BLOCKED] = "BLOCKED"
43};
44
45static const char * const mplevents[] = {
46 [PLINK_UNDEFINED] = "NONE",
47 [OPN_ACPT] = "OPN_ACPT",
48 [OPN_RJCT] = "OPN_RJCT",
49 [OPN_IGNR] = "OPN_IGNR",
50 [CNF_ACPT] = "CNF_ACPT",
51 [CNF_RJCT] = "CNF_RJCT",
52 [CNF_IGNR] = "CNF_IGNR",
53 [CLS_ACPT] = "CLS_ACPT",
54 [CLS_IGNR] = "CLS_IGNR"
55};
56
57/* We only need a valid sta if user configured a minimum rssi_threshold. */
58static bool rssi_threshold_check(struct ieee80211_sub_if_data *sdata,
59 struct sta_info *sta)
60{
61 s32 rssi_threshold = sdata->u.mesh.mshcfg.rssi_threshold;
62 return rssi_threshold == 0 ||
63 (sta &&
64 (s8)-ewma_signal_read(&sta->rx_stats.avg_signal) >
65 rssi_threshold);
66}
67
68/**
69 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
70 *
71 * @sta: mesh peer link to restart
72 *
73 * Locking: this function must be called holding sta->mesh->plink_lock
74 */
75static inline void mesh_plink_fsm_restart(struct sta_info *sta)
76{
77 lockdep_assert_held(&sta->mesh->plink_lock);
78 sta->mesh->plink_state = NL80211_PLINK_LISTEN;
79 sta->mesh->llid = sta->mesh->plid = sta->mesh->reason = 0;
80 sta->mesh->plink_retries = 0;
81}
82
83/*
84 * mesh_set_short_slot_time - enable / disable ERP short slot time.
85 *
86 * The standard indirectly mandates mesh STAs to turn off short slot time by
87 * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we
88 * can't be sneaky about it. Enable short slot time if all mesh STAs in the
89 * MBSS support ERP rates.
90 *
91 * Returns BSS_CHANGED_ERP_SLOT or 0 for no change.
92 */
93static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata)
94{
95 struct ieee80211_local *local = sdata->local;
96 enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
97 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
98 struct sta_info *sta;
99 u32 erp_rates = 0, changed = 0;
100 int i;
101 bool short_slot = false;
102
103 if (band == IEEE80211_BAND_5GHZ) {
104 /* (IEEE 802.11-2012 19.4.5) */
105 short_slot = true;
106 goto out;
107 } else if (band != IEEE80211_BAND_2GHZ)
108 goto out;
109
110 for (i = 0; i < sband->n_bitrates; i++)
111 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)
112 erp_rates |= BIT(i);
113
114 if (!erp_rates)
115 goto out;
116
117 rcu_read_lock();
118 list_for_each_entry_rcu(sta, &local->sta_list, list) {
119 if (sdata != sta->sdata ||
120 sta->mesh->plink_state != NL80211_PLINK_ESTAB)
121 continue;
122
123 short_slot = false;
124 if (erp_rates & sta->sta.supp_rates[band])
125 short_slot = true;
126 else
127 break;
128 }
129 rcu_read_unlock();
130
131out:
132 if (sdata->vif.bss_conf.use_short_slot != short_slot) {
133 sdata->vif.bss_conf.use_short_slot = short_slot;
134 changed = BSS_CHANGED_ERP_SLOT;
135 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n",
136 sdata->vif.addr, short_slot);
137 }
138 return changed;
139}
140
141/**
142 * mesh_set_ht_prot_mode - set correct HT protection mode
143 *
144 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
145 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
146 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
147 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode
148 * is selected if all peers in our 20/40MHz MBSS support HT and atleast one
149 * HT20 peer is present. Otherwise no-protection mode is selected.
150 */
151static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
152{
153 struct ieee80211_local *local = sdata->local;
154 struct sta_info *sta;
155 u16 ht_opmode;
156 bool non_ht_sta = false, ht20_sta = false;
157
158 switch (sdata->vif.bss_conf.chandef.width) {
159 case NL80211_CHAN_WIDTH_20_NOHT:
160 case NL80211_CHAN_WIDTH_5:
161 case NL80211_CHAN_WIDTH_10:
162 return 0;
163 default:
164 break;
165 }
166
167 rcu_read_lock();
168 list_for_each_entry_rcu(sta, &local->sta_list, list) {
169 if (sdata != sta->sdata ||
170 sta->mesh->plink_state != NL80211_PLINK_ESTAB)
171 continue;
172
173 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20)
174 continue;
175
176 if (!sta->sta.ht_cap.ht_supported) {
177 mpl_dbg(sdata, "nonHT sta (%pM) is present\n",
178 sta->sta.addr);
179 non_ht_sta = true;
180 break;
181 }
182
183 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr);
184 ht20_sta = true;
185 }
186 rcu_read_unlock();
187
188 if (non_ht_sta)
189 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
190 else if (ht20_sta &&
191 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20)
192 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
193 else
194 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
195
196 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode)
197 return 0;
198
199 sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
200 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
201 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode);
202 return BSS_CHANGED_HT;
203}
204
205static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
206 struct sta_info *sta,
207 enum ieee80211_self_protected_actioncode action,
208 u8 *da, u16 llid, u16 plid, u16 reason)
209{
210 struct ieee80211_local *local = sdata->local;
211 struct sk_buff *skb;
212 struct ieee80211_tx_info *info;
213 struct ieee80211_mgmt *mgmt;
214 bool include_plid = false;
215 u16 peering_proto = 0;
216 u8 *pos, ie_len = 4;
217 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) +
218 sizeof(mgmt->u.action.u.self_prot);
219 int err = -ENOMEM;
220
221 skb = dev_alloc_skb(local->tx_headroom +
222 hdr_len +
223 2 + /* capability info */
224 2 + /* AID */
225 2 + 8 + /* supported rates */
226 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
227 2 + sdata->u.mesh.mesh_id_len +
228 2 + sizeof(struct ieee80211_meshconf_ie) +
229 2 + sizeof(struct ieee80211_ht_cap) +
230 2 + sizeof(struct ieee80211_ht_operation) +
231 2 + sizeof(struct ieee80211_vht_cap) +
232 2 + sizeof(struct ieee80211_vht_operation) +
233 2 + 8 + /* peering IE */
234 sdata->u.mesh.ie_len);
235 if (!skb)
236 return err;
237 info = IEEE80211_SKB_CB(skb);
238 skb_reserve(skb, local->tx_headroom);
239 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
240 memset(mgmt, 0, hdr_len);
241 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
242 IEEE80211_STYPE_ACTION);
243 memcpy(mgmt->da, da, ETH_ALEN);
244 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
245 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
246 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
247 mgmt->u.action.u.self_prot.action_code = action;
248
249 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
250 enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
251
252 /* capability info */
253 pos = skb_put(skb, 2);
254 memset(pos, 0, 2);
255 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
256 /* AID */
257 pos = skb_put(skb, 2);
258 put_unaligned_le16(sta->sta.aid, pos);
259 }
260 if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
261 ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
262 mesh_add_rsn_ie(sdata, skb) ||
263 mesh_add_meshid_ie(sdata, skb) ||
264 mesh_add_meshconf_ie(sdata, skb))
265 goto free;
266 } else { /* WLAN_SP_MESH_PEERING_CLOSE */
267 info->flags |= IEEE80211_TX_CTL_NO_ACK;
268 if (mesh_add_meshid_ie(sdata, skb))
269 goto free;
270 }
271
272 /* Add Mesh Peering Management element */
273 switch (action) {
274 case WLAN_SP_MESH_PEERING_OPEN:
275 break;
276 case WLAN_SP_MESH_PEERING_CONFIRM:
277 ie_len += 2;
278 include_plid = true;
279 break;
280 case WLAN_SP_MESH_PEERING_CLOSE:
281 if (plid) {
282 ie_len += 2;
283 include_plid = true;
284 }
285 ie_len += 2; /* reason code */
286 break;
287 default:
288 err = -EINVAL;
289 goto free;
290 }
291
292 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
293 goto free;
294
295 pos = skb_put(skb, 2 + ie_len);
296 *pos++ = WLAN_EID_PEER_MGMT;
297 *pos++ = ie_len;
298 memcpy(pos, &peering_proto, 2);
299 pos += 2;
300 put_unaligned_le16(llid, pos);
301 pos += 2;
302 if (include_plid) {
303 put_unaligned_le16(plid, pos);
304 pos += 2;
305 }
306 if (action == WLAN_SP_MESH_PEERING_CLOSE) {
307 put_unaligned_le16(reason, pos);
308 pos += 2;
309 }
310
311 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
312 if (mesh_add_ht_cap_ie(sdata, skb) ||
313 mesh_add_ht_oper_ie(sdata, skb) ||
314 mesh_add_vht_cap_ie(sdata, skb) ||
315 mesh_add_vht_oper_ie(sdata, skb))
316 goto free;
317 }
318
319 if (mesh_add_vendor_ies(sdata, skb))
320 goto free;
321
322 ieee80211_tx_skb(sdata, skb);
323 return 0;
324free:
325 kfree_skb(skb);
326 return err;
327}
328
329/**
330 * __mesh_plink_deactivate - deactivate mesh peer link
331 *
332 * @sta: mesh peer link to deactivate
333 *
334 * All mesh paths with this peer as next hop will be flushed
335 * Returns beacon changed flag if the beacon content changed.
336 *
337 * Locking: the caller must hold sta->mesh->plink_lock
338 */
339static u32 __mesh_plink_deactivate(struct sta_info *sta)
340{
341 struct ieee80211_sub_if_data *sdata = sta->sdata;
342 u32 changed = 0;
343
344 lockdep_assert_held(&sta->mesh->plink_lock);
345
346 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
347 changed = mesh_plink_dec_estab_count(sdata);
348 sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
349 mesh_path_flush_by_nexthop(sta);
350
351 ieee80211_mps_sta_status_update(sta);
352 changed |= ieee80211_mps_set_sta_local_pm(sta,
353 NL80211_MESH_POWER_UNKNOWN);
354
355 return changed;
356}
357
358/**
359 * mesh_plink_deactivate - deactivate mesh peer link
360 *
361 * @sta: mesh peer link to deactivate
362 *
363 * All mesh paths with this peer as next hop will be flushed
364 */
365u32 mesh_plink_deactivate(struct sta_info *sta)
366{
367 struct ieee80211_sub_if_data *sdata = sta->sdata;
368 u32 changed;
369
370 spin_lock_bh(&sta->mesh->plink_lock);
371 changed = __mesh_plink_deactivate(sta);
372 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED;
373 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE,
374 sta->sta.addr, sta->mesh->llid, sta->mesh->plid,
375 sta->mesh->reason);
376 spin_unlock_bh(&sta->mesh->plink_lock);
377
378 return changed;
379}
380
381static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
382 struct sta_info *sta,
383 struct ieee802_11_elems *elems, bool insert)
384{
385 struct ieee80211_local *local = sdata->local;
386 enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
387 struct ieee80211_supported_band *sband;
388 u32 rates, basic_rates = 0, changed = 0;
389 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth;
390
391 sband = local->hw.wiphy->bands[band];
392 rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates);
393
394 spin_lock_bh(&sta->mesh->plink_lock);
395 sta->rx_stats.last_rx = jiffies;
396
397 /* rates and capabilities don't change during peering */
398 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB &&
399 sta->mesh->processed_beacon)
400 goto out;
401 sta->mesh->processed_beacon = true;
402
403 if (sta->sta.supp_rates[band] != rates)
404 changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
405 sta->sta.supp_rates[band] = rates;
406
407 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
408 elems->ht_cap_elem, sta))
409 changed |= IEEE80211_RC_BW_CHANGED;
410
411 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
412 elems->vht_cap_elem, sta);
413
414 if (bw != sta->sta.bandwidth)
415 changed |= IEEE80211_RC_BW_CHANGED;
416
417 /* HT peer is operating 20MHz-only */
418 if (elems->ht_operation &&
419 !(elems->ht_operation->ht_param &
420 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
421 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20)
422 changed |= IEEE80211_RC_BW_CHANGED;
423 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20;
424 }
425
426 if (insert)
427 rate_control_rate_init(sta);
428 else
429 rate_control_rate_update(local, sband, sta, changed);
430out:
431 spin_unlock_bh(&sta->mesh->plink_lock);
432}
433
434static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata)
435{
436 struct sta_info *sta;
437 unsigned long *aid_map;
438 int aid;
439
440 aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1),
441 sizeof(*aid_map), GFP_KERNEL);
442 if (!aid_map)
443 return -ENOMEM;
444
445 /* reserve aid 0 for mcast indication */
446 __set_bit(0, aid_map);
447
448 rcu_read_lock();
449 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list)
450 __set_bit(sta->sta.aid, aid_map);
451 rcu_read_unlock();
452
453 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1);
454 kfree(aid_map);
455
456 if (aid > IEEE80211_MAX_AID)
457 return -ENOBUFS;
458
459 return aid;
460}
461
462static struct sta_info *
463__mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
464{
465 struct sta_info *sta;
466 int aid;
467
468 if (sdata->local->num_sta >= MESH_MAX_PLINKS)
469 return NULL;
470
471 aid = mesh_allocate_aid(sdata);
472 if (aid < 0)
473 return NULL;
474
475 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
476 if (!sta)
477 return NULL;
478
479 sta->mesh->plink_state = NL80211_PLINK_LISTEN;
480 sta->sta.wme = true;
481 sta->sta.aid = aid;
482
483 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
484 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
485 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
486
487 return sta;
488}
489
490static struct sta_info *
491mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
492 struct ieee802_11_elems *elems)
493{
494 struct sta_info *sta = NULL;
495
496 /* Userspace handles station allocation */
497 if (sdata->u.mesh.user_mpm ||
498 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED)
499 cfg80211_notify_new_peer_candidate(sdata->dev, addr,
500 elems->ie_start,
501 elems->total_len,
502 GFP_KERNEL);
503 else
504 sta = __mesh_sta_info_alloc(sdata, addr);
505
506 return sta;
507}
508
509/*
510 * mesh_sta_info_get - return mesh sta info entry for @addr.
511 *
512 * @sdata: local meshif
513 * @addr: peer's address
514 * @elems: IEs from beacon or mesh peering frame.
515 *
516 * Return existing or newly allocated sta_info under RCU read lock.
517 * (re)initialize with given IEs.
518 */
519static struct sta_info *
520mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
521 u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU)
522{
523 struct sta_info *sta = NULL;
524
525 rcu_read_lock();
526 sta = sta_info_get(sdata, addr);
527 if (sta) {
528 mesh_sta_info_init(sdata, sta, elems, false);
529 } else {
530 rcu_read_unlock();
531 /* can't run atomic */
532 sta = mesh_sta_info_alloc(sdata, addr, elems);
533 if (!sta) {
534 rcu_read_lock();
535 return NULL;
536 }
537
538 mesh_sta_info_init(sdata, sta, elems, true);
539
540 if (sta_info_insert_rcu(sta))
541 return NULL;
542 }
543
544 return sta;
545}
546
547/*
548 * mesh_neighbour_update - update or initialize new mesh neighbor.
549 *
550 * @sdata: local meshif
551 * @addr: peer's address
552 * @elems: IEs from beacon or mesh peering frame
553 *
554 * Initiates peering if appropriate.
555 */
556void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
557 u8 *hw_addr,
558 struct ieee802_11_elems *elems)
559{
560 struct sta_info *sta;
561 u32 changed = 0;
562
563 sta = mesh_sta_info_get(sdata, hw_addr, elems);
564 if (!sta)
565 goto out;
566
567 if (mesh_peer_accepts_plinks(elems) &&
568 sta->mesh->plink_state == NL80211_PLINK_LISTEN &&
569 sdata->u.mesh.accepting_plinks &&
570 sdata->u.mesh.mshcfg.auto_open_plinks &&
571 rssi_threshold_check(sdata, sta))
572 changed = mesh_plink_open(sta);
573
574 ieee80211_mps_frame_release(sta, elems);
575out:
576 rcu_read_unlock();
577 ieee80211_mbss_info_change_notify(sdata, changed);
578}
579
580static void mesh_plink_timer(unsigned long data)
581{
582 struct sta_info *sta;
583 u16 reason = 0;
584 struct ieee80211_sub_if_data *sdata;
585 struct mesh_config *mshcfg;
586 enum ieee80211_self_protected_actioncode action = 0;
587
588 /*
589 * This STA is valid because sta_info_destroy() will
590 * del_timer_sync() this timer after having made sure
591 * it cannot be readded (by deleting the plink.)
592 */
593 sta = (struct sta_info *) data;
594
595 if (sta->sdata->local->quiescing)
596 return;
597
598 spin_lock_bh(&sta->mesh->plink_lock);
599
600 /* If a timer fires just before a state transition on another CPU,
601 * we may have already extended the timeout and changed state by the
602 * time we've acquired the lock and arrived here. In that case,
603 * skip this timer and wait for the new one.
604 */
605 if (time_before(jiffies, sta->mesh->plink_timer.expires)) {
606 mpl_dbg(sta->sdata,
607 "Ignoring timer for %pM in state %s (timer adjusted)",
608 sta->sta.addr, mplstates[sta->mesh->plink_state]);
609 spin_unlock_bh(&sta->mesh->plink_lock);
610 return;
611 }
612
613 /* del_timer() and handler may race when entering these states */
614 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN ||
615 sta->mesh->plink_state == NL80211_PLINK_ESTAB) {
616 mpl_dbg(sta->sdata,
617 "Ignoring timer for %pM in state %s (timer deleted)",
618 sta->sta.addr, mplstates[sta->mesh->plink_state]);
619 spin_unlock_bh(&sta->mesh->plink_lock);
620 return;
621 }
622
623 mpl_dbg(sta->sdata,
624 "Mesh plink timer for %pM fired on state %s\n",
625 sta->sta.addr, mplstates[sta->mesh->plink_state]);
626 sdata = sta->sdata;
627 mshcfg = &sdata->u.mesh.mshcfg;
628
629 switch (sta->mesh->plink_state) {
630 case NL80211_PLINK_OPN_RCVD:
631 case NL80211_PLINK_OPN_SNT:
632 /* retry timer */
633 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) {
634 u32 rand;
635 mpl_dbg(sta->sdata,
636 "Mesh plink for %pM (retry, timeout): %d %d\n",
637 sta->sta.addr, sta->mesh->plink_retries,
638 sta->mesh->plink_timeout);
639 get_random_bytes(&rand, sizeof(u32));
640 sta->mesh->plink_timeout = sta->mesh->plink_timeout +
641 rand % sta->mesh->plink_timeout;
642 ++sta->mesh->plink_retries;
643 mod_plink_timer(sta, sta->mesh->plink_timeout);
644 action = WLAN_SP_MESH_PEERING_OPEN;
645 break;
646 }
647 reason = WLAN_REASON_MESH_MAX_RETRIES;
648 /* fall through on else */
649 case NL80211_PLINK_CNF_RCVD:
650 /* confirm timer */
651 if (!reason)
652 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT;
653 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
654 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
655 action = WLAN_SP_MESH_PEERING_CLOSE;
656 break;
657 case NL80211_PLINK_HOLDING:
658 /* holding timer */
659 del_timer(&sta->mesh->plink_timer);
660 mesh_plink_fsm_restart(sta);
661 break;
662 default:
663 break;
664 }
665 spin_unlock_bh(&sta->mesh->plink_lock);
666 if (action)
667 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
668 sta->mesh->llid, sta->mesh->plid, reason);
669}
670
671static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout)
672{
673 sta->mesh->plink_timer.expires = jiffies + msecs_to_jiffies(timeout);
674 sta->mesh->plink_timer.data = (unsigned long) sta;
675 sta->mesh->plink_timer.function = mesh_plink_timer;
676 sta->mesh->plink_timeout = timeout;
677 add_timer(&sta->mesh->plink_timer);
678}
679
680static bool llid_in_use(struct ieee80211_sub_if_data *sdata,
681 u16 llid)
682{
683 struct ieee80211_local *local = sdata->local;
684 bool in_use = false;
685 struct sta_info *sta;
686
687 rcu_read_lock();
688 list_for_each_entry_rcu(sta, &local->sta_list, list) {
689 if (sdata != sta->sdata)
690 continue;
691
692 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) {
693 in_use = true;
694 break;
695 }
696 }
697 rcu_read_unlock();
698
699 return in_use;
700}
701
702static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata)
703{
704 u16 llid;
705
706 do {
707 get_random_bytes(&llid, sizeof(llid));
708 } while (llid_in_use(sdata, llid));
709
710 return llid;
711}
712
713u32 mesh_plink_open(struct sta_info *sta)
714{
715 struct ieee80211_sub_if_data *sdata = sta->sdata;
716 u32 changed;
717
718 if (!test_sta_flag(sta, WLAN_STA_AUTH))
719 return 0;
720
721 spin_lock_bh(&sta->mesh->plink_lock);
722 sta->mesh->llid = mesh_get_new_llid(sdata);
723 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN &&
724 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) {
725 spin_unlock_bh(&sta->mesh->plink_lock);
726 return 0;
727 }
728 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT;
729 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
730 spin_unlock_bh(&sta->mesh->plink_lock);
731 mpl_dbg(sdata,
732 "Mesh plink: starting establishment with %pM\n",
733 sta->sta.addr);
734
735 /* set the non-peer mode to active during peering */
736 changed = ieee80211_mps_local_status_update(sdata);
737
738 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN,
739 sta->sta.addr, sta->mesh->llid, 0, 0);
740 return changed;
741}
742
743u32 mesh_plink_block(struct sta_info *sta)
744{
745 u32 changed;
746
747 spin_lock_bh(&sta->mesh->plink_lock);
748 changed = __mesh_plink_deactivate(sta);
749 sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
750 spin_unlock_bh(&sta->mesh->plink_lock);
751
752 return changed;
753}
754
755static void mesh_plink_close(struct ieee80211_sub_if_data *sdata,
756 struct sta_info *sta,
757 enum plink_event event)
758{
759 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
760 u16 reason = (event == CLS_ACPT) ?
761 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG;
762
763 sta->mesh->reason = reason;
764 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
765 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
766}
767
768static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata,
769 struct sta_info *sta)
770{
771 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
772 u32 changed = 0;
773
774 del_timer(&sta->mesh->plink_timer);
775 sta->mesh->plink_state = NL80211_PLINK_ESTAB;
776 changed |= mesh_plink_inc_estab_count(sdata);
777 changed |= mesh_set_ht_prot_mode(sdata);
778 changed |= mesh_set_short_slot_time(sdata);
779 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr);
780 ieee80211_mps_sta_status_update(sta);
781 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode);
782 return changed;
783}
784
785/**
786 * mesh_plink_fsm - step @sta MPM based on @event
787 *
788 * @sdata: interface
789 * @sta: mesh neighbor
790 * @event: peering event
791 *
792 * Return: changed MBSS flags
793 */
794static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata,
795 struct sta_info *sta, enum plink_event event)
796{
797 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
798 enum ieee80211_self_protected_actioncode action = 0;
799 u32 changed = 0;
800
801 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr,
802 mplstates[sta->mesh->plink_state], mplevents[event]);
803
804 spin_lock_bh(&sta->mesh->plink_lock);
805 switch (sta->mesh->plink_state) {
806 case NL80211_PLINK_LISTEN:
807 switch (event) {
808 case CLS_ACPT:
809 mesh_plink_fsm_restart(sta);
810 break;
811 case OPN_ACPT:
812 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
813 sta->mesh->llid = mesh_get_new_llid(sdata);
814 mesh_plink_timer_set(sta,
815 mshcfg->dot11MeshRetryTimeout);
816
817 /* set the non-peer mode to active during peering */
818 changed |= ieee80211_mps_local_status_update(sdata);
819 action = WLAN_SP_MESH_PEERING_OPEN;
820 break;
821 default:
822 break;
823 }
824 break;
825 case NL80211_PLINK_OPN_SNT:
826 switch (event) {
827 case OPN_RJCT:
828 case CNF_RJCT:
829 case CLS_ACPT:
830 mesh_plink_close(sdata, sta, event);
831 action = WLAN_SP_MESH_PEERING_CLOSE;
832 break;
833 case OPN_ACPT:
834 /* retry timer is left untouched */
835 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
836 action = WLAN_SP_MESH_PEERING_CONFIRM;
837 break;
838 case CNF_ACPT:
839 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD;
840 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout);
841 break;
842 default:
843 break;
844 }
845 break;
846 case NL80211_PLINK_OPN_RCVD:
847 switch (event) {
848 case OPN_RJCT:
849 case CNF_RJCT:
850 case CLS_ACPT:
851 mesh_plink_close(sdata, sta, event);
852 action = WLAN_SP_MESH_PEERING_CLOSE;
853 break;
854 case OPN_ACPT:
855 action = WLAN_SP_MESH_PEERING_CONFIRM;
856 break;
857 case CNF_ACPT:
858 changed |= mesh_plink_establish(sdata, sta);
859 break;
860 default:
861 break;
862 }
863 break;
864 case NL80211_PLINK_CNF_RCVD:
865 switch (event) {
866 case OPN_RJCT:
867 case CNF_RJCT:
868 case CLS_ACPT:
869 mesh_plink_close(sdata, sta, event);
870 action = WLAN_SP_MESH_PEERING_CLOSE;
871 break;
872 case OPN_ACPT:
873 changed |= mesh_plink_establish(sdata, sta);
874 action = WLAN_SP_MESH_PEERING_CONFIRM;
875 break;
876 default:
877 break;
878 }
879 break;
880 case NL80211_PLINK_ESTAB:
881 switch (event) {
882 case CLS_ACPT:
883 changed |= __mesh_plink_deactivate(sta);
884 changed |= mesh_set_ht_prot_mode(sdata);
885 changed |= mesh_set_short_slot_time(sdata);
886 mesh_plink_close(sdata, sta, event);
887 action = WLAN_SP_MESH_PEERING_CLOSE;
888 break;
889 case OPN_ACPT:
890 action = WLAN_SP_MESH_PEERING_CONFIRM;
891 break;
892 default:
893 break;
894 }
895 break;
896 case NL80211_PLINK_HOLDING:
897 switch (event) {
898 case CLS_ACPT:
899 del_timer(&sta->mesh->plink_timer);
900 mesh_plink_fsm_restart(sta);
901 break;
902 case OPN_ACPT:
903 case CNF_ACPT:
904 case OPN_RJCT:
905 case CNF_RJCT:
906 action = WLAN_SP_MESH_PEERING_CLOSE;
907 break;
908 default:
909 break;
910 }
911 break;
912 default:
913 /* should not get here, PLINK_BLOCKED is dealt with at the
914 * beginning of the function
915 */
916 break;
917 }
918 spin_unlock_bh(&sta->mesh->plink_lock);
919 if (action) {
920 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
921 sta->mesh->llid, sta->mesh->plid,
922 sta->mesh->reason);
923
924 /* also send confirm in open case */
925 if (action == WLAN_SP_MESH_PEERING_OPEN) {
926 mesh_plink_frame_tx(sdata, sta,
927 WLAN_SP_MESH_PEERING_CONFIRM,
928 sta->sta.addr, sta->mesh->llid,
929 sta->mesh->plid, 0);
930 }
931 }
932
933 return changed;
934}
935
936/*
937 * mesh_plink_get_event - get correct MPM event
938 *
939 * @sdata: interface
940 * @sta: peer, leave NULL if processing a frame from a new suitable peer
941 * @elems: peering management IEs
942 * @ftype: frame type
943 * @llid: peer's peer link ID
944 * @plid: peer's local link ID
945 *
946 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as
947 * an error.
948 */
949static enum plink_event
950mesh_plink_get_event(struct ieee80211_sub_if_data *sdata,
951 struct sta_info *sta,
952 struct ieee802_11_elems *elems,
953 enum ieee80211_self_protected_actioncode ftype,
954 u16 llid, u16 plid)
955{
956 enum plink_event event = PLINK_UNDEFINED;
957 u8 ie_len = elems->peering_len;
958 bool matches_local;
959
960 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE ||
961 mesh_matches_local(sdata, elems));
962
963 /* deny open request from non-matching peer */
964 if (!matches_local && !sta) {
965 event = OPN_RJCT;
966 goto out;
967 }
968
969 if (!sta) {
970 if (ftype != WLAN_SP_MESH_PEERING_OPEN) {
971 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
972 goto out;
973 }
974 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
975 if (!mesh_plink_free_count(sdata)) {
976 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
977 goto out;
978 }
979
980 /* new matching peer */
981 event = OPN_ACPT;
982 goto out;
983 } else {
984 if (!test_sta_flag(sta, WLAN_STA_AUTH)) {
985 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
986 goto out;
987 }
988 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED)
989 goto out;
990 }
991
992 switch (ftype) {
993 case WLAN_SP_MESH_PEERING_OPEN:
994 if (!matches_local)
995 event = OPN_RJCT;
996 if (!mesh_plink_free_count(sdata) ||
997 (sta->mesh->plid && sta->mesh->plid != plid))
998 event = OPN_IGNR;
999 else
1000 event = OPN_ACPT;
1001 break;
1002 case WLAN_SP_MESH_PEERING_CONFIRM:
1003 if (!matches_local)
1004 event = CNF_RJCT;
1005 if (!mesh_plink_free_count(sdata) ||
1006 sta->mesh->llid != llid ||
1007 (sta->mesh->plid && sta->mesh->plid != plid))
1008 event = CNF_IGNR;
1009 else
1010 event = CNF_ACPT;
1011 break;
1012 case WLAN_SP_MESH_PEERING_CLOSE:
1013 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
1014 /* Do not check for llid or plid. This does not
1015 * follow the standard but since multiple plinks
1016 * per sta are not supported, it is necessary in
1017 * order to avoid a livelock when MP A sees an
1018 * establish peer link to MP B but MP B does not
1019 * see it. This can be caused by a timeout in
1020 * B's peer link establishment or B beign
1021 * restarted.
1022 */
1023 event = CLS_ACPT;
1024 else if (sta->mesh->plid != plid)
1025 event = CLS_IGNR;
1026 else if (ie_len == 8 && sta->mesh->llid != llid)
1027 event = CLS_IGNR;
1028 else
1029 event = CLS_ACPT;
1030 break;
1031 default:
1032 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
1033 break;
1034 }
1035
1036out:
1037 return event;
1038}
1039
1040static void
1041mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
1042 struct ieee80211_mgmt *mgmt,
1043 struct ieee802_11_elems *elems)
1044{
1045
1046 struct sta_info *sta;
1047 enum plink_event event;
1048 enum ieee80211_self_protected_actioncode ftype;
1049 u32 changed = 0;
1050 u8 ie_len = elems->peering_len;
1051 u16 plid, llid = 0;
1052
1053 if (!elems->peering) {
1054 mpl_dbg(sdata,
1055 "Mesh plink: missing necessary peer link ie\n");
1056 return;
1057 }
1058
1059 if (elems->rsn_len &&
1060 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
1061 mpl_dbg(sdata,
1062 "Mesh plink: can't establish link with secure peer\n");
1063 return;
1064 }
1065
1066 ftype = mgmt->u.action.u.self_prot.action_code;
1067 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
1068 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
1069 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
1070 && ie_len != 8)) {
1071 mpl_dbg(sdata,
1072 "Mesh plink: incorrect plink ie length %d %d\n",
1073 ftype, ie_len);
1074 return;
1075 }
1076
1077 if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
1078 (!elems->mesh_id || !elems->mesh_config)) {
1079 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
1080 return;
1081 }
1082 /* Note the lines below are correct, the llid in the frame is the plid
1083 * from the point of view of this host.
1084 */
1085 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering));
1086 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
1087 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
1088 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering));
1089
1090 /* WARNING: Only for sta pointer, is dropped & re-acquired */
1091 rcu_read_lock();
1092
1093 sta = sta_info_get(sdata, mgmt->sa);
1094
1095 if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
1096 !rssi_threshold_check(sdata, sta)) {
1097 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
1098 mgmt->sa);
1099 goto unlock_rcu;
1100 }
1101
1102 /* Now we will figure out the appropriate event... */
1103 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid);
1104
1105 if (event == OPN_ACPT) {
1106 rcu_read_unlock();
1107 /* allocate sta entry if necessary and update info */
1108 sta = mesh_sta_info_get(sdata, mgmt->sa, elems);
1109 if (!sta) {
1110 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
1111 goto unlock_rcu;
1112 }
1113 sta->mesh->plid = plid;
1114 } else if (!sta && event == OPN_RJCT) {
1115 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE,
1116 mgmt->sa, 0, plid,
1117 WLAN_REASON_MESH_CONFIG);
1118 goto unlock_rcu;
1119 } else if (!sta || event == PLINK_UNDEFINED) {
1120 /* something went wrong */
1121 goto unlock_rcu;
1122 }
1123
1124 if (event == CNF_ACPT) {
1125 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */
1126 if (!sta->mesh->plid)
1127 sta->mesh->plid = plid;
1128
1129 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt));
1130 }
1131
1132 changed |= mesh_plink_fsm(sdata, sta, event);
1133
1134unlock_rcu:
1135 rcu_read_unlock();
1136
1137 if (changed)
1138 ieee80211_mbss_info_change_notify(sdata, changed);
1139}
1140
1141void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
1142 struct ieee80211_mgmt *mgmt, size_t len,
1143 struct ieee80211_rx_status *rx_status)
1144{
1145 struct ieee802_11_elems elems;
1146 size_t baselen;
1147 u8 *baseaddr;
1148
1149 /* need action_code, aux */
1150 if (len < IEEE80211_MIN_ACTION_SIZE + 3)
1151 return;
1152
1153 if (sdata->u.mesh.user_mpm)
1154 /* userspace must register for these */
1155 return;
1156
1157 if (is_multicast_ether_addr(mgmt->da)) {
1158 mpl_dbg(sdata,
1159 "Mesh plink: ignore frame from multicast address\n");
1160 return;
1161 }
1162
1163 baseaddr = mgmt->u.action.u.self_prot.variable;
1164 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
1165 if (mgmt->u.action.u.self_prot.action_code ==
1166 WLAN_SP_MESH_PEERING_CONFIRM) {
1167 baseaddr += 4;
1168 baselen += 4;
1169
1170 if (baselen > len)
1171 return;
1172 }
1173 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems);
1174 mesh_process_plink_frame(sdata, mgmt, &elems);
1175}