1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2008, 2009 open80211s Ltd.
4 * Copyright (C) 2019, 2021-2024 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
23 enum 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
35 static 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
45 static 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. */
58 static 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->deflink.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 */
75 static 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 */
93 static u64 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;
99 u64 changed = 0;
100 int i;
101 bool short_slot = false;
102
103 sband = ieee80211_get_sband(sdata);
104 if (!sband)
105 return changed;
106
107 if (sband->band == NL80211_BAND_5GHZ) {
108 /* (IEEE 802.11-2012 19.4.5) */
109 short_slot = true;
110 goto out;
111 } else if (sband->band != NL80211_BAND_2GHZ) {
112 goto out;
113 }
114
115 for (i = 0; i < sband->n_bitrates; i++)
116 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)
117 erp_rates |= BIT(i);
118
119 if (!erp_rates)
120 goto out;
121
122 rcu_read_lock();
123 list_for_each_entry_rcu(sta, &local->sta_list, list) {
124 if (sdata != sta->sdata ||
125 sta->mesh->plink_state != NL80211_PLINK_ESTAB)
126 continue;
127
128 short_slot = false;
129 if (erp_rates & sta->sta.deflink.supp_rates[sband->band])
130 short_slot = true;
131 else
132 break;
133 }
134 rcu_read_unlock();
135
136 out:
137 if (sdata->vif.bss_conf.use_short_slot != short_slot) {
138 sdata->vif.bss_conf.use_short_slot = short_slot;
139 changed = BSS_CHANGED_ERP_SLOT;
140 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n",
141 sdata->vif.addr, short_slot);
142 }
143 return changed;
144 }
145
146 /**
147 * mesh_set_ht_prot_mode - set correct HT protection mode
148 * @sdata: the (mesh) interface to handle
149 *
150 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
151 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
152 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
153 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode
154 * is selected if all peers in our 20/40MHz MBSS support HT and at least one
155 * HT20 peer is present. Otherwise no-protection mode is selected.
156 *
157 * Returns: BSS_CHANGED_HT or 0 for no change
158 */
159 static u64 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
160 {
161 struct ieee80211_local *local = sdata->local;
162 struct sta_info *sta;
163 u16 ht_opmode;
164 bool non_ht_sta = false, ht20_sta = false;
165
166 switch (sdata->vif.bss_conf.chanreq.oper.width) {
167 case NL80211_CHAN_WIDTH_20_NOHT:
168 case NL80211_CHAN_WIDTH_5:
169 case NL80211_CHAN_WIDTH_10:
170 return 0;
171 default:
172 break;
173 }
174
175 rcu_read_lock();
176 list_for_each_entry_rcu(sta, &local->sta_list, list) {
177 if (sdata != sta->sdata ||
178 sta->mesh->plink_state != NL80211_PLINK_ESTAB)
179 continue;
180
181 if (sta->sta.deflink.bandwidth > IEEE80211_STA_RX_BW_20)
182 continue;
183
184 if (!sta->sta.deflink.ht_cap.ht_supported) {
185 mpl_dbg(sdata, "nonHT sta (%pM) is present\n",
186 sta->sta.addr);
187 non_ht_sta = true;
188 break;
189 }
190
191 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr);
192 ht20_sta = true;
193 }
194 rcu_read_unlock();
195
196 if (non_ht_sta)
197 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
198 else if (ht20_sta &&
199 sdata->vif.bss_conf.chanreq.oper.width > NL80211_CHAN_WIDTH_20)
200 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
201 else
202 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
203
204 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode)
205 return 0;
206
207 sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
208 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
209 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode);
210 return BSS_CHANGED_HT;
211 }
212
213 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
214 struct sta_info *sta,
215 enum ieee80211_self_protected_actioncode action,
216 u8 *da, u16 llid, u16 plid, u16 reason)
217 {
218 struct ieee80211_local *local = sdata->local;
219 struct sk_buff *skb;
220 struct ieee80211_tx_info *info;
221 struct ieee80211_mgmt *mgmt;
222 bool include_plid = false;
223 u16 peering_proto = 0;
224 u8 *pos, ie_len = 4;
225 u8 ie_len_he_cap, ie_len_eht_cap;
226 int hdr_len = offsetofend(struct ieee80211_mgmt, u.action.u.self_prot);
227 int err = -ENOMEM;
228
229 ie_len_he_cap = ieee80211_ie_len_he_cap(sdata);
230 ie_len_eht_cap = ieee80211_ie_len_eht_cap(sdata);
231 skb = dev_alloc_skb(local->tx_headroom +
232 hdr_len +
233 2 + /* capability info */
234 2 + /* AID */
235 2 + 8 + /* supported rates */
236 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
237 2 + sdata->u.mesh.mesh_id_len +
238 2 + sizeof(struct ieee80211_meshconf_ie) +
239 2 + sizeof(struct ieee80211_ht_cap) +
240 2 + sizeof(struct ieee80211_ht_operation) +
241 2 + sizeof(struct ieee80211_vht_cap) +
242 2 + sizeof(struct ieee80211_vht_operation) +
243 ie_len_he_cap +
244 2 + 1 + sizeof(struct ieee80211_he_operation) +
245 sizeof(struct ieee80211_he_6ghz_oper) +
246 2 + 1 + sizeof(struct ieee80211_he_6ghz_capa) +
247 ie_len_eht_cap +
248 2 + 1 + offsetof(struct ieee80211_eht_operation, optional) +
249 offsetof(struct ieee80211_eht_operation_info, optional) +
250 2 + 8 + /* peering IE */
251 sdata->u.mesh.ie_len);
252 if (!skb)
253 return err;
254 info = IEEE80211_SKB_CB(skb);
255 skb_reserve(skb, local->tx_headroom);
256 mgmt = skb_put_zero(skb, hdr_len);
257 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
258 IEEE80211_STYPE_ACTION);
259 memcpy(mgmt->da, da, ETH_ALEN);
260 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
261 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
262 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
263 mgmt->u.action.u.self_prot.action_code = action;
264
265 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
266 struct ieee80211_supported_band *sband;
267 u32 rate_flags, basic_rates;
268
269 sband = ieee80211_get_sband(sdata);
270 if (!sband) {
271 err = -EINVAL;
272 goto free;
273 }
274
275 /* capability info */
276 pos = skb_put_zero(skb, 2);
277 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
278 /* AID */
279 pos = skb_put(skb, 2);
280 put_unaligned_le16(sta->sta.aid, pos);
281 }
282
283 rate_flags =
284 ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chanreq.oper);
285 basic_rates = sdata->vif.bss_conf.basic_rates;
286
287 if (ieee80211_put_srates_elem(skb, sband, basic_rates,
288 rate_flags, 0,
289 WLAN_EID_SUPP_RATES) ||
290 ieee80211_put_srates_elem(skb, sband, basic_rates,
291 rate_flags, 0,
292 WLAN_EID_EXT_SUPP_RATES) ||
293 mesh_add_rsn_ie(sdata, skb) ||
294 mesh_add_meshid_ie(sdata, skb) ||
295 mesh_add_meshconf_ie(sdata, skb))
296 goto free;
297 } else { /* WLAN_SP_MESH_PEERING_CLOSE */
298 info->flags |= IEEE80211_TX_CTL_NO_ACK;
299 if (mesh_add_meshid_ie(sdata, skb))
300 goto free;
301 }
302
303 /* Add Mesh Peering Management element */
304 switch (action) {
305 case WLAN_SP_MESH_PEERING_OPEN:
306 break;
307 case WLAN_SP_MESH_PEERING_CONFIRM:
308 ie_len += 2;
309 include_plid = true;
310 break;
311 case WLAN_SP_MESH_PEERING_CLOSE:
312 if (plid) {
313 ie_len += 2;
314 include_plid = true;
315 }
316 ie_len += 2; /* reason code */
317 break;
318 default:
319 err = -EINVAL;
320 goto free;
321 }
322
323 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
324 goto free;
325
326 pos = skb_put(skb, 2 + ie_len);
327 *pos++ = WLAN_EID_PEER_MGMT;
328 *pos++ = ie_len;
329 memcpy(pos, &peering_proto, 2);
330 pos += 2;
331 put_unaligned_le16(llid, pos);
332 pos += 2;
333 if (include_plid) {
334 put_unaligned_le16(plid, pos);
335 pos += 2;
336 }
337 if (action == WLAN_SP_MESH_PEERING_CLOSE) {
338 put_unaligned_le16(reason, pos);
339 pos += 2;
340 }
341
342 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
343 if (mesh_add_ht_cap_ie(sdata, skb) ||
344 mesh_add_ht_oper_ie(sdata, skb) ||
345 mesh_add_vht_cap_ie(sdata, skb) ||
346 mesh_add_vht_oper_ie(sdata, skb) ||
347 mesh_add_he_cap_ie(sdata, skb, ie_len_he_cap) ||
348 mesh_add_he_oper_ie(sdata, skb) ||
349 mesh_add_he_6ghz_cap_ie(sdata, skb) ||
350 mesh_add_eht_cap_ie(sdata, skb, ie_len_eht_cap) ||
351 mesh_add_eht_oper_ie(sdata, skb))
352 goto free;
353 }
354
355 if (mesh_add_vendor_ies(sdata, skb))
356 goto free;
357
358 ieee80211_tx_skb(sdata, skb);
359 return 0;
360 free:
361 kfree_skb(skb);
362 return err;
363 }
364
365 /**
366 * __mesh_plink_deactivate - deactivate mesh peer link
367 *
368 * @sta: mesh peer link to deactivate
369 *
370 * Mesh paths with this peer as next hop should be flushed
371 * by the caller outside of plink_lock.
372 *
373 * Returns: beacon changed flag if the beacon content changed.
374 *
375 * Locking: the caller must hold sta->mesh->plink_lock
376 */
377 static u64 __mesh_plink_deactivate(struct sta_info *sta)
378 {
379 struct ieee80211_sub_if_data *sdata = sta->sdata;
380 u64 changed = 0;
381
382 lockdep_assert_held(&sta->mesh->plink_lock);
383
384 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
385 changed = mesh_plink_dec_estab_count(sdata);
386 sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
387
388 ieee80211_mps_sta_status_update(sta);
389 changed |= ieee80211_mps_set_sta_local_pm(sta,
390 NL80211_MESH_POWER_UNKNOWN);
391
392 return changed;
393 }
394
395 /**
396 * mesh_plink_deactivate - deactivate mesh peer link
397 *
398 * @sta: mesh peer link to deactivate
399 *
400 * All mesh paths with this peer as next hop will be flushed
401 *
402 * Returns: beacon changed flag if the beacon content changed.
403 */
404 u64 mesh_plink_deactivate(struct sta_info *sta)
405 {
406 struct ieee80211_sub_if_data *sdata = sta->sdata;
407 u64 changed;
408
409 spin_lock_bh(&sta->mesh->plink_lock);
410 changed = __mesh_plink_deactivate(sta);
411
412 if (!sdata->u.mesh.user_mpm) {
413 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED;
414 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE,
415 sta->sta.addr, sta->mesh->llid,
416 sta->mesh->plid, sta->mesh->reason);
417 }
418 spin_unlock_bh(&sta->mesh->plink_lock);
419 if (!sdata->u.mesh.user_mpm)
420 del_timer_sync(&sta->mesh->plink_timer);
421 mesh_path_flush_by_nexthop(sta);
422
423 /* make sure no readers can access nexthop sta from here on */
424 synchronize_net();
425
426 return changed;
427 }
428
429 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
430 struct sta_info *sta,
431 struct ieee802_11_elems *elems)
432 {
433 struct ieee80211_local *local = sdata->local;
434 struct ieee80211_supported_band *sband;
435 u32 rates, basic_rates = 0, changed = 0;
436 enum ieee80211_sta_rx_bandwidth bw = sta->sta.deflink.bandwidth;
437
438 sband = ieee80211_get_sband(sdata);
439 if (!sband)
440 return;
441
442 rates = ieee80211_sta_get_rates(sdata, elems, sband->band,
443 &basic_rates);
444
445 spin_lock_bh(&sta->mesh->plink_lock);
446 sta->deflink.rx_stats.last_rx = jiffies;
447
448 /* rates and capabilities don't change during peering */
449 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB &&
450 sta->mesh->processed_beacon)
451 goto out;
452 sta->mesh->processed_beacon = true;
453
454 if (sta->sta.deflink.supp_rates[sband->band] != rates)
455 changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
456 sta->sta.deflink.supp_rates[sband->band] = rates;
457
458 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
459 elems->ht_cap_elem,
460 &sta->deflink))
461 changed |= IEEE80211_RC_BW_CHANGED;
462
463 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
464 elems->vht_cap_elem, NULL,
465 &sta->deflink);
466
467 ieee80211_he_cap_ie_to_sta_he_cap(sdata, sband, elems->he_cap,
468 elems->he_cap_len,
469 elems->he_6ghz_capa,
470 &sta->deflink);
471
472 ieee80211_eht_cap_ie_to_sta_eht_cap(sdata, sband, elems->he_cap,
473 elems->he_cap_len,
474 elems->eht_cap, elems->eht_cap_len,
475 &sta->deflink);
476
477 if (bw != sta->sta.deflink.bandwidth)
478 changed |= IEEE80211_RC_BW_CHANGED;
479
480 /* HT peer is operating 20MHz-only */
481 if (elems->ht_operation &&
482 !(elems->ht_operation->ht_param &
483 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
484 if (sta->sta.deflink.bandwidth != IEEE80211_STA_RX_BW_20)
485 changed |= IEEE80211_RC_BW_CHANGED;
486 sta->sta.deflink.bandwidth = IEEE80211_STA_RX_BW_20;
487 }
488
489 if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
490 rate_control_rate_init(sta);
491 else
492 rate_control_rate_update(local, sband, sta, 0, changed);
493 out:
494 spin_unlock_bh(&sta->mesh->plink_lock);
495 }
496
497 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata)
498 {
499 struct sta_info *sta;
500 unsigned long *aid_map;
501 int aid;
502
503 aid_map = bitmap_zalloc(IEEE80211_MAX_AID + 1, GFP_KERNEL);
504 if (!aid_map)
505 return -ENOMEM;
506
507 /* reserve aid 0 for mcast indication */
508 __set_bit(0, aid_map);
509
510 rcu_read_lock();
511 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list)
512 __set_bit(sta->sta.aid, aid_map);
513 rcu_read_unlock();
514
515 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1);
516 bitmap_free(aid_map);
517
518 if (aid > IEEE80211_MAX_AID)
519 return -ENOBUFS;
520
521 return aid;
522 }
523
524 static struct sta_info *
525 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
526 {
527 struct sta_info *sta;
528 int aid;
529
530 if (sdata->local->num_sta >= MESH_MAX_PLINKS)
531 return NULL;
532
533 aid = mesh_allocate_aid(sdata);
534 if (aid < 0)
535 return NULL;
536
537 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
538 if (!sta)
539 return NULL;
540
541 sta->mesh->plink_state = NL80211_PLINK_LISTEN;
542 sta->sta.wme = true;
543 sta->sta.aid = aid;
544
545 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
546 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
547 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
548
549 return sta;
550 }
551
552 static struct sta_info *
553 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
554 struct ieee802_11_elems *elems,
555 struct ieee80211_rx_status *rx_status)
556 {
557 struct sta_info *sta = NULL;
558
559 /* Userspace handles station allocation */
560 if (sdata->u.mesh.user_mpm ||
561 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) {
562 if (mesh_peer_accepts_plinks(elems) &&
563 mesh_plink_availables(sdata)) {
564 int sig = 0;
565
566 if (ieee80211_hw_check(&sdata->local->hw, SIGNAL_DBM))
567 sig = rx_status->signal;
568
569 cfg80211_notify_new_peer_candidate(sdata->dev, addr,
570 elems->ie_start,
571 elems->total_len,
572 sig, GFP_KERNEL);
573 }
574 } else
575 sta = __mesh_sta_info_alloc(sdata, addr);
576
577 return sta;
578 }
579
580 /*
581 * mesh_sta_info_get - return mesh sta info entry for @addr.
582 *
583 * @sdata: local meshif
584 * @addr: peer's address
585 * @elems: IEs from beacon or mesh peering frame.
586 * @rx_status: rx status for the frame for signal reporting
587 *
588 * Return existing or newly allocated sta_info under RCU read lock.
589 * (re)initialize with given IEs.
590 */
591 static struct sta_info *
592 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
593 u8 *addr, struct ieee802_11_elems *elems,
594 struct ieee80211_rx_status *rx_status) __acquires(RCU)
595 {
596 struct sta_info *sta = NULL;
597
598 rcu_read_lock();
599 sta = sta_info_get(sdata, addr);
600 if (sta) {
601 mesh_sta_info_init(sdata, sta, elems);
602 } else {
603 rcu_read_unlock();
604 /* can't run atomic */
605 sta = mesh_sta_info_alloc(sdata, addr, elems, rx_status);
606 if (!sta) {
607 rcu_read_lock();
608 return NULL;
609 }
610
611 mesh_sta_info_init(sdata, sta, elems);
612
613 if (sta_info_insert_rcu(sta))
614 return NULL;
615 }
616
617 return sta;
618 }
619
620 /*
621 * mesh_neighbour_update - update or initialize new mesh neighbor.
622 *
623 * @sdata: local meshif
624 * @addr: peer's address
625 * @elems: IEs from beacon or mesh peering frame
626 * @rx_status: rx status for the frame for signal reporting
627 *
628 * Initiates peering if appropriate.
629 */
630 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
631 u8 *hw_addr,
632 struct ieee802_11_elems *elems,
633 struct ieee80211_rx_status *rx_status)
634 {
635 struct sta_info *sta;
636 u64 changed = 0;
637
638 sta = mesh_sta_info_get(sdata, hw_addr, elems, rx_status);
639 if (!sta)
640 goto out;
641
642 sta->mesh->connected_to_gate = elems->mesh_config->meshconf_form &
643 IEEE80211_MESHCONF_FORM_CONNECTED_TO_GATE;
644
645 if (mesh_peer_accepts_plinks(elems) &&
646 sta->mesh->plink_state == NL80211_PLINK_LISTEN &&
647 sdata->u.mesh.accepting_plinks &&
648 sdata->u.mesh.mshcfg.auto_open_plinks &&
649 rssi_threshold_check(sdata, sta))
650 changed = mesh_plink_open(sta);
651
652 ieee80211_mps_frame_release(sta, elems);
653 out:
654 rcu_read_unlock();
655 ieee80211_mbss_info_change_notify(sdata, changed);
656 }
657
658 void mesh_plink_timer(struct timer_list *t)
659 {
660 struct mesh_sta *mesh = from_timer(mesh, t, plink_timer);
661 struct sta_info *sta;
662 u16 reason = 0;
663 struct ieee80211_sub_if_data *sdata;
664 struct mesh_config *mshcfg;
665 enum ieee80211_self_protected_actioncode action = 0;
666
667 /*
668 * This STA is valid because sta_info_destroy() will
669 * del_timer_sync() this timer after having made sure
670 * it cannot be readded (by deleting the plink.)
671 */
672 sta = mesh->plink_sta;
673
674 if (sta->sdata->local->quiescing)
675 return;
676
677 spin_lock_bh(&sta->mesh->plink_lock);
678
679 /* If a timer fires just before a state transition on another CPU,
680 * we may have already extended the timeout and changed state by the
681 * time we've acquired the lock and arrived here. In that case,
682 * skip this timer and wait for the new one.
683 */
684 if (time_before(jiffies, sta->mesh->plink_timer.expires)) {
685 mpl_dbg(sta->sdata,
686 "Ignoring timer for %pM in state %s (timer adjusted)",
687 sta->sta.addr, mplstates[sta->mesh->plink_state]);
688 spin_unlock_bh(&sta->mesh->plink_lock);
689 return;
690 }
691
692 /* del_timer() and handler may race when entering these states */
693 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN ||
694 sta->mesh->plink_state == NL80211_PLINK_ESTAB) {
695 mpl_dbg(sta->sdata,
696 "Ignoring timer for %pM in state %s (timer deleted)",
697 sta->sta.addr, mplstates[sta->mesh->plink_state]);
698 spin_unlock_bh(&sta->mesh->plink_lock);
699 return;
700 }
701
702 mpl_dbg(sta->sdata,
703 "Mesh plink timer for %pM fired on state %s\n",
704 sta->sta.addr, mplstates[sta->mesh->plink_state]);
705 sdata = sta->sdata;
706 mshcfg = &sdata->u.mesh.mshcfg;
707
708 switch (sta->mesh->plink_state) {
709 case NL80211_PLINK_OPN_RCVD:
710 case NL80211_PLINK_OPN_SNT:
711 /* retry timer */
712 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) {
713 u32 rand;
714 mpl_dbg(sta->sdata,
715 "Mesh plink for %pM (retry, timeout): %d %d\n",
716 sta->sta.addr, sta->mesh->plink_retries,
717 sta->mesh->plink_timeout);
718 get_random_bytes(&rand, sizeof(u32));
719 sta->mesh->plink_timeout = sta->mesh->plink_timeout +
720 rand % sta->mesh->plink_timeout;
721 ++sta->mesh->plink_retries;
722 mod_plink_timer(sta, sta->mesh->plink_timeout);
723 action = WLAN_SP_MESH_PEERING_OPEN;
724 break;
725 }
726 reason = WLAN_REASON_MESH_MAX_RETRIES;
727 fallthrough;
728 case NL80211_PLINK_CNF_RCVD:
729 /* confirm timer */
730 if (!reason)
731 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT;
732 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
733 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
734 action = WLAN_SP_MESH_PEERING_CLOSE;
735 break;
736 case NL80211_PLINK_HOLDING:
737 /* holding timer */
738 del_timer(&sta->mesh->plink_timer);
739 mesh_plink_fsm_restart(sta);
740 break;
741 default:
742 break;
743 }
744 spin_unlock_bh(&sta->mesh->plink_lock);
745 if (action)
746 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
747 sta->mesh->llid, sta->mesh->plid, reason);
748 }
749
750 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout)
751 {
752 sta->mesh->plink_timeout = timeout;
753 mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout));
754 }
755
756 static bool llid_in_use(struct ieee80211_sub_if_data *sdata,
757 u16 llid)
758 {
759 struct ieee80211_local *local = sdata->local;
760 bool in_use = false;
761 struct sta_info *sta;
762
763 rcu_read_lock();
764 list_for_each_entry_rcu(sta, &local->sta_list, list) {
765 if (sdata != sta->sdata)
766 continue;
767
768 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) {
769 in_use = true;
770 break;
771 }
772 }
773 rcu_read_unlock();
774
775 return in_use;
776 }
777
778 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata)
779 {
780 u16 llid;
781
782 do {
783 get_random_bytes(&llid, sizeof(llid));
784 } while (llid_in_use(sdata, llid));
785
786 return llid;
787 }
788
789 u64 mesh_plink_open(struct sta_info *sta)
790 {
791 struct ieee80211_sub_if_data *sdata = sta->sdata;
792 u64 changed;
793
794 if (!test_sta_flag(sta, WLAN_STA_AUTH))
795 return 0;
796
797 spin_lock_bh(&sta->mesh->plink_lock);
798 sta->mesh->llid = mesh_get_new_llid(sdata);
799 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN &&
800 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) {
801 spin_unlock_bh(&sta->mesh->plink_lock);
802 return 0;
803 }
804 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT;
805 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
806 spin_unlock_bh(&sta->mesh->plink_lock);
807 mpl_dbg(sdata,
808 "Mesh plink: starting establishment with %pM\n",
809 sta->sta.addr);
810
811 /* set the non-peer mode to active during peering */
812 changed = ieee80211_mps_local_status_update(sdata);
813
814 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN,
815 sta->sta.addr, sta->mesh->llid, 0, 0);
816 return changed;
817 }
818
819 u64 mesh_plink_block(struct sta_info *sta)
820 {
821 u64 changed;
822
823 spin_lock_bh(&sta->mesh->plink_lock);
824 changed = __mesh_plink_deactivate(sta);
825 sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
826 spin_unlock_bh(&sta->mesh->plink_lock);
827 mesh_path_flush_by_nexthop(sta);
828
829 return changed;
830 }
831
832 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata,
833 struct sta_info *sta,
834 enum plink_event event)
835 {
836 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
837 u16 reason = (event == CLS_ACPT) ?
838 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG;
839
840 sta->mesh->reason = reason;
841 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
842 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
843 }
844
845 static u64 mesh_plink_establish(struct ieee80211_sub_if_data *sdata,
846 struct sta_info *sta)
847 {
848 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
849 u64 changed = 0;
850
851 del_timer(&sta->mesh->plink_timer);
852 sta->mesh->plink_state = NL80211_PLINK_ESTAB;
853 changed |= mesh_plink_inc_estab_count(sdata);
854 changed |= mesh_set_ht_prot_mode(sdata);
855 changed |= mesh_set_short_slot_time(sdata);
856 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr);
857 ieee80211_mps_sta_status_update(sta);
858 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode);
859 return changed;
860 }
861
862 /**
863 * mesh_plink_fsm - step @sta MPM based on @event
864 *
865 * @sdata: interface
866 * @sta: mesh neighbor
867 * @event: peering event
868 *
869 * Return: changed MBSS flags
870 */
871 static u64 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata,
872 struct sta_info *sta, enum plink_event event)
873 {
874 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
875 enum ieee80211_self_protected_actioncode action = 0;
876 u64 changed = 0;
877 bool flush = false;
878
879 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr,
880 mplstates[sta->mesh->plink_state], mplevents[event]);
881
882 spin_lock_bh(&sta->mesh->plink_lock);
883 switch (sta->mesh->plink_state) {
884 case NL80211_PLINK_LISTEN:
885 switch (event) {
886 case CLS_ACPT:
887 mesh_plink_fsm_restart(sta);
888 break;
889 case OPN_ACPT:
890 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
891 sta->mesh->llid = mesh_get_new_llid(sdata);
892 mesh_plink_timer_set(sta,
893 mshcfg->dot11MeshRetryTimeout);
894
895 /* set the non-peer mode to active during peering */
896 changed |= ieee80211_mps_local_status_update(sdata);
897 action = WLAN_SP_MESH_PEERING_OPEN;
898 break;
899 default:
900 break;
901 }
902 break;
903 case NL80211_PLINK_OPN_SNT:
904 switch (event) {
905 case OPN_RJCT:
906 case CNF_RJCT:
907 case CLS_ACPT:
908 mesh_plink_close(sdata, sta, event);
909 action = WLAN_SP_MESH_PEERING_CLOSE;
910 break;
911 case OPN_ACPT:
912 /* retry timer is left untouched */
913 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
914 action = WLAN_SP_MESH_PEERING_CONFIRM;
915 break;
916 case CNF_ACPT:
917 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD;
918 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout);
919 break;
920 default:
921 break;
922 }
923 break;
924 case NL80211_PLINK_OPN_RCVD:
925 switch (event) {
926 case OPN_RJCT:
927 case CNF_RJCT:
928 case CLS_ACPT:
929 mesh_plink_close(sdata, sta, event);
930 action = WLAN_SP_MESH_PEERING_CLOSE;
931 break;
932 case OPN_ACPT:
933 action = WLAN_SP_MESH_PEERING_CONFIRM;
934 break;
935 case CNF_ACPT:
936 changed |= mesh_plink_establish(sdata, sta);
937 break;
938 default:
939 break;
940 }
941 break;
942 case NL80211_PLINK_CNF_RCVD:
943 switch (event) {
944 case OPN_RJCT:
945 case CNF_RJCT:
946 case CLS_ACPT:
947 mesh_plink_close(sdata, sta, event);
948 action = WLAN_SP_MESH_PEERING_CLOSE;
949 break;
950 case OPN_ACPT:
951 changed |= mesh_plink_establish(sdata, sta);
952 action = WLAN_SP_MESH_PEERING_CONFIRM;
953 break;
954 default:
955 break;
956 }
957 break;
958 case NL80211_PLINK_ESTAB:
959 switch (event) {
960 case CLS_ACPT:
961 changed |= __mesh_plink_deactivate(sta);
962 changed |= mesh_set_ht_prot_mode(sdata);
963 changed |= mesh_set_short_slot_time(sdata);
964 mesh_plink_close(sdata, sta, event);
965 action = WLAN_SP_MESH_PEERING_CLOSE;
966 flush = true;
967 break;
968 case OPN_ACPT:
969 action = WLAN_SP_MESH_PEERING_CONFIRM;
970 break;
971 default:
972 break;
973 }
974 break;
975 case NL80211_PLINK_HOLDING:
976 switch (event) {
977 case CLS_ACPT:
978 del_timer(&sta->mesh->plink_timer);
979 mesh_plink_fsm_restart(sta);
980 break;
981 case OPN_ACPT:
982 case CNF_ACPT:
983 case OPN_RJCT:
984 case CNF_RJCT:
985 action = WLAN_SP_MESH_PEERING_CLOSE;
986 break;
987 default:
988 break;
989 }
990 break;
991 default:
992 /* should not get here, PLINK_BLOCKED is dealt with at the
993 * beginning of the function
994 */
995 break;
996 }
997 spin_unlock_bh(&sta->mesh->plink_lock);
998 if (flush)
999 mesh_path_flush_by_nexthop(sta);
1000 if (action) {
1001 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
1002 sta->mesh->llid, sta->mesh->plid,
1003 sta->mesh->reason);
1004
1005 /* also send confirm in open case */
1006 if (action == WLAN_SP_MESH_PEERING_OPEN) {
1007 mesh_plink_frame_tx(sdata, sta,
1008 WLAN_SP_MESH_PEERING_CONFIRM,
1009 sta->sta.addr, sta->mesh->llid,
1010 sta->mesh->plid, 0);
1011 }
1012 }
1013
1014 return changed;
1015 }
1016
1017 /*
1018 * mesh_plink_get_event - get correct MPM event
1019 *
1020 * @sdata: interface
1021 * @sta: peer, leave NULL if processing a frame from a new suitable peer
1022 * @elems: peering management IEs
1023 * @ftype: frame type
1024 * @llid: peer's peer link ID
1025 * @plid: peer's local link ID
1026 *
1027 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as
1028 * an error.
1029 */
1030 static enum plink_event
1031 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata,
1032 struct sta_info *sta,
1033 struct ieee802_11_elems *elems,
1034 enum ieee80211_self_protected_actioncode ftype,
1035 u16 llid, u16 plid)
1036 {
1037 enum plink_event event = PLINK_UNDEFINED;
1038 u8 ie_len = elems->peering_len;
1039 bool matches_local;
1040
1041 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE ||
1042 mesh_matches_local(sdata, elems));
1043
1044 /* deny open request from non-matching peer */
1045 if (!matches_local && !sta) {
1046 event = OPN_RJCT;
1047 goto out;
1048 }
1049
1050 if (!sta) {
1051 if (ftype != WLAN_SP_MESH_PEERING_OPEN) {
1052 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
1053 goto out;
1054 }
1055 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
1056 if (!mesh_plink_free_count(sdata)) {
1057 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
1058 goto out;
1059 }
1060
1061 /* new matching peer */
1062 event = OPN_ACPT;
1063 goto out;
1064 } else {
1065 if (!test_sta_flag(sta, WLAN_STA_AUTH)) {
1066 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
1067 goto out;
1068 }
1069 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED)
1070 goto out;
1071 }
1072
1073 switch (ftype) {
1074 case WLAN_SP_MESH_PEERING_OPEN:
1075 if (!matches_local)
1076 event = OPN_RJCT;
1077 else if (!mesh_plink_free_count(sdata) ||
1078 (sta->mesh->plid && sta->mesh->plid != plid))
1079 event = OPN_IGNR;
1080 else
1081 event = OPN_ACPT;
1082 break;
1083 case WLAN_SP_MESH_PEERING_CONFIRM:
1084 if (!matches_local)
1085 event = CNF_RJCT;
1086 else if (!mesh_plink_free_count(sdata) ||
1087 sta->mesh->llid != llid ||
1088 (sta->mesh->plid && sta->mesh->plid != plid))
1089 event = CNF_IGNR;
1090 else
1091 event = CNF_ACPT;
1092 break;
1093 case WLAN_SP_MESH_PEERING_CLOSE:
1094 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
1095 /* Do not check for llid or plid. This does not
1096 * follow the standard but since multiple plinks
1097 * per sta are not supported, it is necessary in
1098 * order to avoid a livelock when MP A sees an
1099 * establish peer link to MP B but MP B does not
1100 * see it. This can be caused by a timeout in
1101 * B's peer link establishment or B beign
1102 * restarted.
1103 */
1104 event = CLS_ACPT;
1105 else if (sta->mesh->plid != plid)
1106 event = CLS_IGNR;
1107 else if (ie_len == 8 && sta->mesh->llid != llid)
1108 event = CLS_IGNR;
1109 else
1110 event = CLS_ACPT;
1111 break;
1112 default:
1113 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
1114 break;
1115 }
1116
1117 out:
1118 return event;
1119 }
1120
1121 static void
1122 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
1123 struct ieee80211_mgmt *mgmt,
1124 struct ieee802_11_elems *elems,
1125 struct ieee80211_rx_status *rx_status)
1126 {
1127
1128 struct sta_info *sta;
1129 enum plink_event event;
1130 enum ieee80211_self_protected_actioncode ftype;
1131 u64 changed = 0;
1132 u8 ie_len = elems->peering_len;
1133 u16 plid, llid = 0;
1134
1135 if (!elems->peering) {
1136 mpl_dbg(sdata,
1137 "Mesh plink: missing necessary peer link ie\n");
1138 return;
1139 }
1140
1141 if (elems->rsn_len &&
1142 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
1143 mpl_dbg(sdata,
1144 "Mesh plink: can't establish link with secure peer\n");
1145 return;
1146 }
1147
1148 ftype = mgmt->u.action.u.self_prot.action_code;
1149 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
1150 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
1151 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
1152 && ie_len != 8)) {
1153 mpl_dbg(sdata,
1154 "Mesh plink: incorrect plink ie length %d %d\n",
1155 ftype, ie_len);
1156 return;
1157 }
1158
1159 if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
1160 (!elems->mesh_id || !elems->mesh_config)) {
1161 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
1162 return;
1163 }
1164 /* Note the lines below are correct, the llid in the frame is the plid
1165 * from the point of view of this host.
1166 */
1167 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering));
1168 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
1169 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
1170 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering));
1171
1172 /* WARNING: Only for sta pointer, is dropped & re-acquired */
1173 rcu_read_lock();
1174
1175 sta = sta_info_get(sdata, mgmt->sa);
1176
1177 if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
1178 !rssi_threshold_check(sdata, sta)) {
1179 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
1180 mgmt->sa);
1181 goto unlock_rcu;
1182 }
1183
1184 /* Now we will figure out the appropriate event... */
1185 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid);
1186
1187 if (event == OPN_ACPT) {
1188 rcu_read_unlock();
1189 /* allocate sta entry if necessary and update info */
1190 sta = mesh_sta_info_get(sdata, mgmt->sa, elems, rx_status);
1191 if (!sta) {
1192 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
1193 goto unlock_rcu;
1194 }
1195 sta->mesh->plid = plid;
1196 } else if (!sta && event == OPN_RJCT) {
1197 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE,
1198 mgmt->sa, 0, plid,
1199 WLAN_REASON_MESH_CONFIG);
1200 goto unlock_rcu;
1201 } else if (!sta || event == PLINK_UNDEFINED) {
1202 /* something went wrong */
1203 goto unlock_rcu;
1204 }
1205
1206 if (event == CNF_ACPT) {
1207 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */
1208 if (!sta->mesh->plid)
1209 sta->mesh->plid = plid;
1210
1211 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt));
1212 }
1213
1214 changed |= mesh_plink_fsm(sdata, sta, event);
1215
1216 unlock_rcu:
1217 rcu_read_unlock();
1218
1219 if (changed)
1220 ieee80211_mbss_info_change_notify(sdata, changed);
1221 }
1222
1223 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
1224 struct ieee80211_mgmt *mgmt, size_t len,
1225 struct ieee80211_rx_status *rx_status)
1226 {
1227 struct ieee802_11_elems *elems;
1228 size_t baselen;
1229 u8 *baseaddr;
1230
1231 /* need action_code, aux */
1232 if (len < IEEE80211_MIN_ACTION_SIZE + 3)
1233 return;
1234
1235 if (sdata->u.mesh.user_mpm)
1236 /* userspace must register for these */
1237 return;
1238
1239 if (is_multicast_ether_addr(mgmt->da)) {
1240 mpl_dbg(sdata,
1241 "Mesh plink: ignore frame from multicast address\n");
1242 return;
1243 }
1244
1245 baseaddr = mgmt->u.action.u.self_prot.variable;
1246 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
1247 if (mgmt->u.action.u.self_prot.action_code ==
1248 WLAN_SP_MESH_PEERING_CONFIRM) {
1249 baseaddr += 4;
1250 baselen += 4;
1251
1252 if (baselen > len)
1253 return;
1254 }
1255 elems = ieee802_11_parse_elems(baseaddr, len - baselen, true, NULL);
1256 if (elems) {
1257 mesh_process_plink_frame(sdata, mgmt, elems, rx_status);
1258 kfree(elems);
1259 }
1260 }
1261
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