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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 * @sdata: the (mesh) interface to handle
148 *
149 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
150 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
151 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
152 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode
153 * is selected if all peers in our 20/40MHz MBSS support HT and at least one
154 * HT20 peer is present. Otherwise no-protection mode is selected.
155 */
156static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
157{
158 struct ieee80211_local *local = sdata->local;
159 struct sta_info *sta;
160 u16 ht_opmode;
161 bool non_ht_sta = false, ht20_sta = false;
162
163 switch (sdata->vif.bss_conf.chandef.width) {
164 case NL80211_CHAN_WIDTH_20_NOHT:
165 case NL80211_CHAN_WIDTH_5:
166 case NL80211_CHAN_WIDTH_10:
167 return 0;
168 default:
169 break;
170 }
171
172 rcu_read_lock();
173 list_for_each_entry_rcu(sta, &local->sta_list, list) {
174 if (sdata != sta->sdata ||
175 sta->mesh->plink_state != NL80211_PLINK_ESTAB)
176 continue;
177
178 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20)
179 continue;
180
181 if (!sta->sta.ht_cap.ht_supported) {
182 mpl_dbg(sdata, "nonHT sta (%pM) is present\n",
183 sta->sta.addr);
184 non_ht_sta = true;
185 break;
186 }
187
188 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr);
189 ht20_sta = true;
190 }
191 rcu_read_unlock();
192
193 if (non_ht_sta)
194 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
195 else if (ht20_sta &&
196 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20)
197 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
198 else
199 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
200
201 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode)
202 return 0;
203
204 sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
205 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
206 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode);
207 return BSS_CHANGED_HT;
208}
209
210static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
211 struct sta_info *sta,
212 enum ieee80211_self_protected_actioncode action,
213 u8 *da, u16 llid, u16 plid, u16 reason)
214{
215 struct ieee80211_local *local = sdata->local;
216 struct sk_buff *skb;
217 struct ieee80211_tx_info *info;
218 struct ieee80211_mgmt *mgmt;
219 bool include_plid = false;
220 u16 peering_proto = 0;
221 u8 *pos, ie_len = 4;
222 u8 ie_len_he_cap;
223 int hdr_len = offsetofend(struct ieee80211_mgmt, u.action.u.self_prot);
224 int err = -ENOMEM;
225
226 ie_len_he_cap = ieee80211_ie_len_he_cap(sdata,
227 NL80211_IFTYPE_MESH_POINT);
228 skb = dev_alloc_skb(local->tx_headroom +
229 hdr_len +
230 2 + /* capability info */
231 2 + /* AID */
232 2 + 8 + /* supported rates */
233 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
234 2 + sdata->u.mesh.mesh_id_len +
235 2 + sizeof(struct ieee80211_meshconf_ie) +
236 2 + sizeof(struct ieee80211_ht_cap) +
237 2 + sizeof(struct ieee80211_ht_operation) +
238 2 + sizeof(struct ieee80211_vht_cap) +
239 2 + sizeof(struct ieee80211_vht_operation) +
240 ie_len_he_cap +
241 2 + 1 + sizeof(struct ieee80211_he_operation) +
242 sizeof(struct ieee80211_he_6ghz_oper) +
243 2 + 1 + sizeof(struct ieee80211_he_6ghz_capa) +
244 2 + 8 + /* peering IE */
245 sdata->u.mesh.ie_len);
246 if (!skb)
247 return err;
248 info = IEEE80211_SKB_CB(skb);
249 skb_reserve(skb, local->tx_headroom);
250 mgmt = skb_put_zero(skb, hdr_len);
251 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
252 IEEE80211_STYPE_ACTION);
253 memcpy(mgmt->da, da, ETH_ALEN);
254 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
255 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
256 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
257 mgmt->u.action.u.self_prot.action_code = action;
258
259 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
260 struct ieee80211_supported_band *sband;
261 enum nl80211_band band;
262
263 sband = ieee80211_get_sband(sdata);
264 if (!sband) {
265 err = -EINVAL;
266 goto free;
267 }
268 band = sband->band;
269
270 /* capability info */
271 pos = skb_put_zero(skb, 2);
272 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
273 /* AID */
274 pos = skb_put(skb, 2);
275 put_unaligned_le16(sta->sta.aid, pos);
276 }
277 if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
278 ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
279 mesh_add_rsn_ie(sdata, skb) ||
280 mesh_add_meshid_ie(sdata, skb) ||
281 mesh_add_meshconf_ie(sdata, skb))
282 goto free;
283 } else { /* WLAN_SP_MESH_PEERING_CLOSE */
284 info->flags |= IEEE80211_TX_CTL_NO_ACK;
285 if (mesh_add_meshid_ie(sdata, skb))
286 goto free;
287 }
288
289 /* Add Mesh Peering Management element */
290 switch (action) {
291 case WLAN_SP_MESH_PEERING_OPEN:
292 break;
293 case WLAN_SP_MESH_PEERING_CONFIRM:
294 ie_len += 2;
295 include_plid = true;
296 break;
297 case WLAN_SP_MESH_PEERING_CLOSE:
298 if (plid) {
299 ie_len += 2;
300 include_plid = true;
301 }
302 ie_len += 2; /* reason code */
303 break;
304 default:
305 err = -EINVAL;
306 goto free;
307 }
308
309 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
310 goto free;
311
312 pos = skb_put(skb, 2 + ie_len);
313 *pos++ = WLAN_EID_PEER_MGMT;
314 *pos++ = ie_len;
315 memcpy(pos, &peering_proto, 2);
316 pos += 2;
317 put_unaligned_le16(llid, pos);
318 pos += 2;
319 if (include_plid) {
320 put_unaligned_le16(plid, pos);
321 pos += 2;
322 }
323 if (action == WLAN_SP_MESH_PEERING_CLOSE) {
324 put_unaligned_le16(reason, pos);
325 pos += 2;
326 }
327
328 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
329 if (mesh_add_ht_cap_ie(sdata, skb) ||
330 mesh_add_ht_oper_ie(sdata, skb) ||
331 mesh_add_vht_cap_ie(sdata, skb) ||
332 mesh_add_vht_oper_ie(sdata, skb) ||
333 mesh_add_he_cap_ie(sdata, skb, ie_len_he_cap) ||
334 mesh_add_he_oper_ie(sdata, skb) ||
335 mesh_add_he_6ghz_cap_ie(sdata, skb))
336 goto free;
337 }
338
339 if (mesh_add_vendor_ies(sdata, skb))
340 goto free;
341
342 ieee80211_tx_skb(sdata, skb);
343 return 0;
344free:
345 kfree_skb(skb);
346 return err;
347}
348
349/**
350 * __mesh_plink_deactivate - deactivate mesh peer link
351 *
352 * @sta: mesh peer link to deactivate
353 *
354 * Mesh paths with this peer as next hop should be flushed
355 * by the caller outside of plink_lock.
356 *
357 * Returns beacon changed flag if the beacon content changed.
358 *
359 * Locking: the caller must hold sta->mesh->plink_lock
360 */
361static u32 __mesh_plink_deactivate(struct sta_info *sta)
362{
363 struct ieee80211_sub_if_data *sdata = sta->sdata;
364 u32 changed = 0;
365
366 lockdep_assert_held(&sta->mesh->plink_lock);
367
368 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
369 changed = mesh_plink_dec_estab_count(sdata);
370 sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
371
372 ieee80211_mps_sta_status_update(sta);
373 changed |= ieee80211_mps_set_sta_local_pm(sta,
374 NL80211_MESH_POWER_UNKNOWN);
375
376 return changed;
377}
378
379/**
380 * mesh_plink_deactivate - deactivate mesh peer link
381 *
382 * @sta: mesh peer link to deactivate
383 *
384 * All mesh paths with this peer as next hop will be flushed
385 */
386u32 mesh_plink_deactivate(struct sta_info *sta)
387{
388 struct ieee80211_sub_if_data *sdata = sta->sdata;
389 u32 changed;
390
391 spin_lock_bh(&sta->mesh->plink_lock);
392 changed = __mesh_plink_deactivate(sta);
393
394 if (!sdata->u.mesh.user_mpm) {
395 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED;
396 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE,
397 sta->sta.addr, sta->mesh->llid,
398 sta->mesh->plid, sta->mesh->reason);
399 }
400 spin_unlock_bh(&sta->mesh->plink_lock);
401 if (!sdata->u.mesh.user_mpm)
402 del_timer_sync(&sta->mesh->plink_timer);
403 mesh_path_flush_by_nexthop(sta);
404
405 /* make sure no readers can access nexthop sta from here on */
406 synchronize_net();
407
408 return changed;
409}
410
411static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
412 struct sta_info *sta,
413 struct ieee802_11_elems *elems)
414{
415 struct ieee80211_local *local = sdata->local;
416 struct ieee80211_supported_band *sband;
417 u32 rates, basic_rates = 0, changed = 0;
418 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth;
419
420 sband = ieee80211_get_sband(sdata);
421 if (!sband)
422 return;
423
424 rates = ieee80211_sta_get_rates(sdata, elems, sband->band,
425 &basic_rates);
426
427 spin_lock_bh(&sta->mesh->plink_lock);
428 sta->rx_stats.last_rx = jiffies;
429
430 /* rates and capabilities don't change during peering */
431 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB &&
432 sta->mesh->processed_beacon)
433 goto out;
434 sta->mesh->processed_beacon = true;
435
436 if (sta->sta.supp_rates[sband->band] != rates)
437 changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
438 sta->sta.supp_rates[sband->band] = rates;
439
440 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
441 elems->ht_cap_elem, sta))
442 changed |= IEEE80211_RC_BW_CHANGED;
443
444 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
445 elems->vht_cap_elem, sta);
446
447 ieee80211_he_cap_ie_to_sta_he_cap(sdata, sband, elems->he_cap,
448 elems->he_cap_len,
449 elems->he_6ghz_capa,
450 sta);
451
452 if (bw != sta->sta.bandwidth)
453 changed |= IEEE80211_RC_BW_CHANGED;
454
455 /* HT peer is operating 20MHz-only */
456 if (elems->ht_operation &&
457 !(elems->ht_operation->ht_param &
458 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
459 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20)
460 changed |= IEEE80211_RC_BW_CHANGED;
461 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20;
462 }
463
464 if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
465 rate_control_rate_init(sta);
466 else
467 rate_control_rate_update(local, sband, sta, changed);
468out:
469 spin_unlock_bh(&sta->mesh->plink_lock);
470}
471
472static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata)
473{
474 struct sta_info *sta;
475 unsigned long *aid_map;
476 int aid;
477
478 aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1),
479 sizeof(*aid_map), GFP_KERNEL);
480 if (!aid_map)
481 return -ENOMEM;
482
483 /* reserve aid 0 for mcast indication */
484 __set_bit(0, aid_map);
485
486 rcu_read_lock();
487 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list)
488 __set_bit(sta->sta.aid, aid_map);
489 rcu_read_unlock();
490
491 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1);
492 kfree(aid_map);
493
494 if (aid > IEEE80211_MAX_AID)
495 return -ENOBUFS;
496
497 return aid;
498}
499
500static struct sta_info *
501__mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
502{
503 struct sta_info *sta;
504 int aid;
505
506 if (sdata->local->num_sta >= MESH_MAX_PLINKS)
507 return NULL;
508
509 aid = mesh_allocate_aid(sdata);
510 if (aid < 0)
511 return NULL;
512
513 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
514 if (!sta)
515 return NULL;
516
517 sta->mesh->plink_state = NL80211_PLINK_LISTEN;
518 sta->sta.wme = true;
519 sta->sta.aid = aid;
520
521 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
522 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
523 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
524
525 return sta;
526}
527
528static struct sta_info *
529mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
530 struct ieee802_11_elems *elems,
531 struct ieee80211_rx_status *rx_status)
532{
533 struct sta_info *sta = NULL;
534
535 /* Userspace handles station allocation */
536 if (sdata->u.mesh.user_mpm ||
537 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) {
538 if (mesh_peer_accepts_plinks(elems) &&
539 mesh_plink_availables(sdata)) {
540 int sig = 0;
541
542 if (ieee80211_hw_check(&sdata->local->hw, SIGNAL_DBM))
543 sig = rx_status->signal;
544
545 cfg80211_notify_new_peer_candidate(sdata->dev, addr,
546 elems->ie_start,
547 elems->total_len,
548 sig, GFP_KERNEL);
549 }
550 } else
551 sta = __mesh_sta_info_alloc(sdata, addr);
552
553 return sta;
554}
555
556/*
557 * mesh_sta_info_get - return mesh sta info entry for @addr.
558 *
559 * @sdata: local meshif
560 * @addr: peer's address
561 * @elems: IEs from beacon or mesh peering frame.
562 * @rx_status: rx status for the frame for signal reporting
563 *
564 * Return existing or newly allocated sta_info under RCU read lock.
565 * (re)initialize with given IEs.
566 */
567static struct sta_info *
568mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
569 u8 *addr, struct ieee802_11_elems *elems,
570 struct ieee80211_rx_status *rx_status) __acquires(RCU)
571{
572 struct sta_info *sta = NULL;
573
574 rcu_read_lock();
575 sta = sta_info_get(sdata, addr);
576 if (sta) {
577 mesh_sta_info_init(sdata, sta, elems);
578 } else {
579 rcu_read_unlock();
580 /* can't run atomic */
581 sta = mesh_sta_info_alloc(sdata, addr, elems, rx_status);
582 if (!sta) {
583 rcu_read_lock();
584 return NULL;
585 }
586
587 mesh_sta_info_init(sdata, sta, elems);
588
589 if (sta_info_insert_rcu(sta))
590 return NULL;
591 }
592
593 return sta;
594}
595
596/*
597 * mesh_neighbour_update - update or initialize new mesh neighbor.
598 *
599 * @sdata: local meshif
600 * @addr: peer's address
601 * @elems: IEs from beacon or mesh peering frame
602 * @rx_status: rx status for the frame for signal reporting
603 *
604 * Initiates peering if appropriate.
605 */
606void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
607 u8 *hw_addr,
608 struct ieee802_11_elems *elems,
609 struct ieee80211_rx_status *rx_status)
610{
611 struct sta_info *sta;
612 u32 changed = 0;
613
614 sta = mesh_sta_info_get(sdata, hw_addr, elems, rx_status);
615 if (!sta)
616 goto out;
617
618 sta->mesh->connected_to_gate = elems->mesh_config->meshconf_form &
619 IEEE80211_MESHCONF_FORM_CONNECTED_TO_GATE;
620
621 if (mesh_peer_accepts_plinks(elems) &&
622 sta->mesh->plink_state == NL80211_PLINK_LISTEN &&
623 sdata->u.mesh.accepting_plinks &&
624 sdata->u.mesh.mshcfg.auto_open_plinks &&
625 rssi_threshold_check(sdata, sta))
626 changed = mesh_plink_open(sta);
627
628 ieee80211_mps_frame_release(sta, elems);
629out:
630 rcu_read_unlock();
631 ieee80211_mbss_info_change_notify(sdata, changed);
632}
633
634void mesh_plink_timer(struct timer_list *t)
635{
636 struct mesh_sta *mesh = from_timer(mesh, t, plink_timer);
637 struct sta_info *sta;
638 u16 reason = 0;
639 struct ieee80211_sub_if_data *sdata;
640 struct mesh_config *mshcfg;
641 enum ieee80211_self_protected_actioncode action = 0;
642
643 /*
644 * This STA is valid because sta_info_destroy() will
645 * del_timer_sync() this timer after having made sure
646 * it cannot be readded (by deleting the plink.)
647 */
648 sta = mesh->plink_sta;
649
650 if (sta->sdata->local->quiescing)
651 return;
652
653 spin_lock_bh(&sta->mesh->plink_lock);
654
655 /* If a timer fires just before a state transition on another CPU,
656 * we may have already extended the timeout and changed state by the
657 * time we've acquired the lock and arrived here. In that case,
658 * skip this timer and wait for the new one.
659 */
660 if (time_before(jiffies, sta->mesh->plink_timer.expires)) {
661 mpl_dbg(sta->sdata,
662 "Ignoring timer for %pM in state %s (timer adjusted)",
663 sta->sta.addr, mplstates[sta->mesh->plink_state]);
664 spin_unlock_bh(&sta->mesh->plink_lock);
665 return;
666 }
667
668 /* del_timer() and handler may race when entering these states */
669 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN ||
670 sta->mesh->plink_state == NL80211_PLINK_ESTAB) {
671 mpl_dbg(sta->sdata,
672 "Ignoring timer for %pM in state %s (timer deleted)",
673 sta->sta.addr, mplstates[sta->mesh->plink_state]);
674 spin_unlock_bh(&sta->mesh->plink_lock);
675 return;
676 }
677
678 mpl_dbg(sta->sdata,
679 "Mesh plink timer for %pM fired on state %s\n",
680 sta->sta.addr, mplstates[sta->mesh->plink_state]);
681 sdata = sta->sdata;
682 mshcfg = &sdata->u.mesh.mshcfg;
683
684 switch (sta->mesh->plink_state) {
685 case NL80211_PLINK_OPN_RCVD:
686 case NL80211_PLINK_OPN_SNT:
687 /* retry timer */
688 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) {
689 u32 rand;
690 mpl_dbg(sta->sdata,
691 "Mesh plink for %pM (retry, timeout): %d %d\n",
692 sta->sta.addr, sta->mesh->plink_retries,
693 sta->mesh->plink_timeout);
694 get_random_bytes(&rand, sizeof(u32));
695 sta->mesh->plink_timeout = sta->mesh->plink_timeout +
696 rand % sta->mesh->plink_timeout;
697 ++sta->mesh->plink_retries;
698 mod_plink_timer(sta, sta->mesh->plink_timeout);
699 action = WLAN_SP_MESH_PEERING_OPEN;
700 break;
701 }
702 reason = WLAN_REASON_MESH_MAX_RETRIES;
703 fallthrough;
704 case NL80211_PLINK_CNF_RCVD:
705 /* confirm timer */
706 if (!reason)
707 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT;
708 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
709 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
710 action = WLAN_SP_MESH_PEERING_CLOSE;
711 break;
712 case NL80211_PLINK_HOLDING:
713 /* holding timer */
714 del_timer(&sta->mesh->plink_timer);
715 mesh_plink_fsm_restart(sta);
716 break;
717 default:
718 break;
719 }
720 spin_unlock_bh(&sta->mesh->plink_lock);
721 if (action)
722 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
723 sta->mesh->llid, sta->mesh->plid, reason);
724}
725
726static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout)
727{
728 sta->mesh->plink_timeout = timeout;
729 mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout));
730}
731
732static bool llid_in_use(struct ieee80211_sub_if_data *sdata,
733 u16 llid)
734{
735 struct ieee80211_local *local = sdata->local;
736 bool in_use = false;
737 struct sta_info *sta;
738
739 rcu_read_lock();
740 list_for_each_entry_rcu(sta, &local->sta_list, list) {
741 if (sdata != sta->sdata)
742 continue;
743
744 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) {
745 in_use = true;
746 break;
747 }
748 }
749 rcu_read_unlock();
750
751 return in_use;
752}
753
754static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata)
755{
756 u16 llid;
757
758 do {
759 get_random_bytes(&llid, sizeof(llid));
760 } while (llid_in_use(sdata, llid));
761
762 return llid;
763}
764
765u32 mesh_plink_open(struct sta_info *sta)
766{
767 struct ieee80211_sub_if_data *sdata = sta->sdata;
768 u32 changed;
769
770 if (!test_sta_flag(sta, WLAN_STA_AUTH))
771 return 0;
772
773 spin_lock_bh(&sta->mesh->plink_lock);
774 sta->mesh->llid = mesh_get_new_llid(sdata);
775 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN &&
776 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) {
777 spin_unlock_bh(&sta->mesh->plink_lock);
778 return 0;
779 }
780 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT;
781 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
782 spin_unlock_bh(&sta->mesh->plink_lock);
783 mpl_dbg(sdata,
784 "Mesh plink: starting establishment with %pM\n",
785 sta->sta.addr);
786
787 /* set the non-peer mode to active during peering */
788 changed = ieee80211_mps_local_status_update(sdata);
789
790 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN,
791 sta->sta.addr, sta->mesh->llid, 0, 0);
792 return changed;
793}
794
795u32 mesh_plink_block(struct sta_info *sta)
796{
797 u32 changed;
798
799 spin_lock_bh(&sta->mesh->plink_lock);
800 changed = __mesh_plink_deactivate(sta);
801 sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
802 spin_unlock_bh(&sta->mesh->plink_lock);
803 mesh_path_flush_by_nexthop(sta);
804
805 return changed;
806}
807
808static void mesh_plink_close(struct ieee80211_sub_if_data *sdata,
809 struct sta_info *sta,
810 enum plink_event event)
811{
812 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
813 u16 reason = (event == CLS_ACPT) ?
814 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG;
815
816 sta->mesh->reason = reason;
817 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
818 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
819}
820
821static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata,
822 struct sta_info *sta)
823{
824 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
825 u32 changed = 0;
826
827 del_timer(&sta->mesh->plink_timer);
828 sta->mesh->plink_state = NL80211_PLINK_ESTAB;
829 changed |= mesh_plink_inc_estab_count(sdata);
830 changed |= mesh_set_ht_prot_mode(sdata);
831 changed |= mesh_set_short_slot_time(sdata);
832 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr);
833 ieee80211_mps_sta_status_update(sta);
834 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode);
835 return changed;
836}
837
838/**
839 * mesh_plink_fsm - step @sta MPM based on @event
840 *
841 * @sdata: interface
842 * @sta: mesh neighbor
843 * @event: peering event
844 *
845 * Return: changed MBSS flags
846 */
847static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata,
848 struct sta_info *sta, enum plink_event event)
849{
850 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
851 enum ieee80211_self_protected_actioncode action = 0;
852 u32 changed = 0;
853 bool flush = false;
854
855 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr,
856 mplstates[sta->mesh->plink_state], mplevents[event]);
857
858 spin_lock_bh(&sta->mesh->plink_lock);
859 switch (sta->mesh->plink_state) {
860 case NL80211_PLINK_LISTEN:
861 switch (event) {
862 case CLS_ACPT:
863 mesh_plink_fsm_restart(sta);
864 break;
865 case OPN_ACPT:
866 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
867 sta->mesh->llid = mesh_get_new_llid(sdata);
868 mesh_plink_timer_set(sta,
869 mshcfg->dot11MeshRetryTimeout);
870
871 /* set the non-peer mode to active during peering */
872 changed |= ieee80211_mps_local_status_update(sdata);
873 action = WLAN_SP_MESH_PEERING_OPEN;
874 break;
875 default:
876 break;
877 }
878 break;
879 case NL80211_PLINK_OPN_SNT:
880 switch (event) {
881 case OPN_RJCT:
882 case CNF_RJCT:
883 case CLS_ACPT:
884 mesh_plink_close(sdata, sta, event);
885 action = WLAN_SP_MESH_PEERING_CLOSE;
886 break;
887 case OPN_ACPT:
888 /* retry timer is left untouched */
889 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
890 action = WLAN_SP_MESH_PEERING_CONFIRM;
891 break;
892 case CNF_ACPT:
893 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD;
894 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout);
895 break;
896 default:
897 break;
898 }
899 break;
900 case NL80211_PLINK_OPN_RCVD:
901 switch (event) {
902 case OPN_RJCT:
903 case CNF_RJCT:
904 case CLS_ACPT:
905 mesh_plink_close(sdata, sta, event);
906 action = WLAN_SP_MESH_PEERING_CLOSE;
907 break;
908 case OPN_ACPT:
909 action = WLAN_SP_MESH_PEERING_CONFIRM;
910 break;
911 case CNF_ACPT:
912 changed |= mesh_plink_establish(sdata, sta);
913 break;
914 default:
915 break;
916 }
917 break;
918 case NL80211_PLINK_CNF_RCVD:
919 switch (event) {
920 case OPN_RJCT:
921 case CNF_RJCT:
922 case CLS_ACPT:
923 mesh_plink_close(sdata, sta, event);
924 action = WLAN_SP_MESH_PEERING_CLOSE;
925 break;
926 case OPN_ACPT:
927 changed |= mesh_plink_establish(sdata, sta);
928 action = WLAN_SP_MESH_PEERING_CONFIRM;
929 break;
930 default:
931 break;
932 }
933 break;
934 case NL80211_PLINK_ESTAB:
935 switch (event) {
936 case CLS_ACPT:
937 changed |= __mesh_plink_deactivate(sta);
938 changed |= mesh_set_ht_prot_mode(sdata);
939 changed |= mesh_set_short_slot_time(sdata);
940 mesh_plink_close(sdata, sta, event);
941 action = WLAN_SP_MESH_PEERING_CLOSE;
942 flush = true;
943 break;
944 case OPN_ACPT:
945 action = WLAN_SP_MESH_PEERING_CONFIRM;
946 break;
947 default:
948 break;
949 }
950 break;
951 case NL80211_PLINK_HOLDING:
952 switch (event) {
953 case CLS_ACPT:
954 del_timer(&sta->mesh->plink_timer);
955 mesh_plink_fsm_restart(sta);
956 break;
957 case OPN_ACPT:
958 case CNF_ACPT:
959 case OPN_RJCT:
960 case CNF_RJCT:
961 action = WLAN_SP_MESH_PEERING_CLOSE;
962 break;
963 default:
964 break;
965 }
966 break;
967 default:
968 /* should not get here, PLINK_BLOCKED is dealt with at the
969 * beginning of the function
970 */
971 break;
972 }
973 spin_unlock_bh(&sta->mesh->plink_lock);
974 if (flush)
975 mesh_path_flush_by_nexthop(sta);
976 if (action) {
977 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
978 sta->mesh->llid, sta->mesh->plid,
979 sta->mesh->reason);
980
981 /* also send confirm in open case */
982 if (action == WLAN_SP_MESH_PEERING_OPEN) {
983 mesh_plink_frame_tx(sdata, sta,
984 WLAN_SP_MESH_PEERING_CONFIRM,
985 sta->sta.addr, sta->mesh->llid,
986 sta->mesh->plid, 0);
987 }
988 }
989
990 return changed;
991}
992
993/*
994 * mesh_plink_get_event - get correct MPM event
995 *
996 * @sdata: interface
997 * @sta: peer, leave NULL if processing a frame from a new suitable peer
998 * @elems: peering management IEs
999 * @ftype: frame type
1000 * @llid: peer's peer link ID
1001 * @plid: peer's local link ID
1002 *
1003 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as
1004 * an error.
1005 */
1006static enum plink_event
1007mesh_plink_get_event(struct ieee80211_sub_if_data *sdata,
1008 struct sta_info *sta,
1009 struct ieee802_11_elems *elems,
1010 enum ieee80211_self_protected_actioncode ftype,
1011 u16 llid, u16 plid)
1012{
1013 enum plink_event event = PLINK_UNDEFINED;
1014 u8 ie_len = elems->peering_len;
1015 bool matches_local;
1016
1017 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE ||
1018 mesh_matches_local(sdata, elems));
1019
1020 /* deny open request from non-matching peer */
1021 if (!matches_local && !sta) {
1022 event = OPN_RJCT;
1023 goto out;
1024 }
1025
1026 if (!sta) {
1027 if (ftype != WLAN_SP_MESH_PEERING_OPEN) {
1028 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
1029 goto out;
1030 }
1031 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
1032 if (!mesh_plink_free_count(sdata)) {
1033 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
1034 goto out;
1035 }
1036
1037 /* new matching peer */
1038 event = OPN_ACPT;
1039 goto out;
1040 } else {
1041 if (!test_sta_flag(sta, WLAN_STA_AUTH)) {
1042 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
1043 goto out;
1044 }
1045 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED)
1046 goto out;
1047 }
1048
1049 switch (ftype) {
1050 case WLAN_SP_MESH_PEERING_OPEN:
1051 if (!matches_local)
1052 event = OPN_RJCT;
1053 if (!mesh_plink_free_count(sdata) ||
1054 (sta->mesh->plid && sta->mesh->plid != plid))
1055 event = OPN_IGNR;
1056 else
1057 event = OPN_ACPT;
1058 break;
1059 case WLAN_SP_MESH_PEERING_CONFIRM:
1060 if (!matches_local)
1061 event = CNF_RJCT;
1062 if (!mesh_plink_free_count(sdata) ||
1063 sta->mesh->llid != llid ||
1064 (sta->mesh->plid && sta->mesh->plid != plid))
1065 event = CNF_IGNR;
1066 else
1067 event = CNF_ACPT;
1068 break;
1069 case WLAN_SP_MESH_PEERING_CLOSE:
1070 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
1071 /* Do not check for llid or plid. This does not
1072 * follow the standard but since multiple plinks
1073 * per sta are not supported, it is necessary in
1074 * order to avoid a livelock when MP A sees an
1075 * establish peer link to MP B but MP B does not
1076 * see it. This can be caused by a timeout in
1077 * B's peer link establishment or B beign
1078 * restarted.
1079 */
1080 event = CLS_ACPT;
1081 else if (sta->mesh->plid != plid)
1082 event = CLS_IGNR;
1083 else if (ie_len == 8 && sta->mesh->llid != llid)
1084 event = CLS_IGNR;
1085 else
1086 event = CLS_ACPT;
1087 break;
1088 default:
1089 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
1090 break;
1091 }
1092
1093out:
1094 return event;
1095}
1096
1097static void
1098mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
1099 struct ieee80211_mgmt *mgmt,
1100 struct ieee802_11_elems *elems,
1101 struct ieee80211_rx_status *rx_status)
1102{
1103
1104 struct sta_info *sta;
1105 enum plink_event event;
1106 enum ieee80211_self_protected_actioncode ftype;
1107 u32 changed = 0;
1108 u8 ie_len = elems->peering_len;
1109 u16 plid, llid = 0;
1110
1111 if (!elems->peering) {
1112 mpl_dbg(sdata,
1113 "Mesh plink: missing necessary peer link ie\n");
1114 return;
1115 }
1116
1117 if (elems->rsn_len &&
1118 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
1119 mpl_dbg(sdata,
1120 "Mesh plink: can't establish link with secure peer\n");
1121 return;
1122 }
1123
1124 ftype = mgmt->u.action.u.self_prot.action_code;
1125 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
1126 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
1127 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
1128 && ie_len != 8)) {
1129 mpl_dbg(sdata,
1130 "Mesh plink: incorrect plink ie length %d %d\n",
1131 ftype, ie_len);
1132 return;
1133 }
1134
1135 if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
1136 (!elems->mesh_id || !elems->mesh_config)) {
1137 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
1138 return;
1139 }
1140 /* Note the lines below are correct, the llid in the frame is the plid
1141 * from the point of view of this host.
1142 */
1143 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering));
1144 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
1145 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
1146 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering));
1147
1148 /* WARNING: Only for sta pointer, is dropped & re-acquired */
1149 rcu_read_lock();
1150
1151 sta = sta_info_get(sdata, mgmt->sa);
1152
1153 if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
1154 !rssi_threshold_check(sdata, sta)) {
1155 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
1156 mgmt->sa);
1157 goto unlock_rcu;
1158 }
1159
1160 /* Now we will figure out the appropriate event... */
1161 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid);
1162
1163 if (event == OPN_ACPT) {
1164 rcu_read_unlock();
1165 /* allocate sta entry if necessary and update info */
1166 sta = mesh_sta_info_get(sdata, mgmt->sa, elems, rx_status);
1167 if (!sta) {
1168 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
1169 goto unlock_rcu;
1170 }
1171 sta->mesh->plid = plid;
1172 } else if (!sta && event == OPN_RJCT) {
1173 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE,
1174 mgmt->sa, 0, plid,
1175 WLAN_REASON_MESH_CONFIG);
1176 goto unlock_rcu;
1177 } else if (!sta || event == PLINK_UNDEFINED) {
1178 /* something went wrong */
1179 goto unlock_rcu;
1180 }
1181
1182 if (event == CNF_ACPT) {
1183 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */
1184 if (!sta->mesh->plid)
1185 sta->mesh->plid = plid;
1186
1187 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt));
1188 }
1189
1190 changed |= mesh_plink_fsm(sdata, sta, event);
1191
1192unlock_rcu:
1193 rcu_read_unlock();
1194
1195 if (changed)
1196 ieee80211_mbss_info_change_notify(sdata, changed);
1197}
1198
1199void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
1200 struct ieee80211_mgmt *mgmt, size_t len,
1201 struct ieee80211_rx_status *rx_status)
1202{
1203 struct ieee802_11_elems elems;
1204 size_t baselen;
1205 u8 *baseaddr;
1206
1207 /* need action_code, aux */
1208 if (len < IEEE80211_MIN_ACTION_SIZE + 3)
1209 return;
1210
1211 if (sdata->u.mesh.user_mpm)
1212 /* userspace must register for these */
1213 return;
1214
1215 if (is_multicast_ether_addr(mgmt->da)) {
1216 mpl_dbg(sdata,
1217 "Mesh plink: ignore frame from multicast address\n");
1218 return;
1219 }
1220
1221 baseaddr = mgmt->u.action.u.self_prot.variable;
1222 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
1223 if (mgmt->u.action.u.self_prot.action_code ==
1224 WLAN_SP_MESH_PEERING_CONFIRM) {
1225 baseaddr += 4;
1226 baselen += 4;
1227
1228 if (baselen > len)
1229 return;
1230 }
1231 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems,
1232 mgmt->bssid, NULL);
1233 mesh_process_plink_frame(sdata, mgmt, &elems, rx_status);
1234}
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}