Loading...
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
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->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 */
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 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
136out:
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 */
159static 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
213static 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;
360free:
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 */
377static 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 */
404u64 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
429static 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 /* FIXME: this check is wrong without SW rate control */
490 if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
491 rate_control_rate_init(&sta->deflink);
492 else
493 rate_control_rate_update(local, sband, &sta->deflink, changed);
494out:
495 spin_unlock_bh(&sta->mesh->plink_lock);
496}
497
498static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata)
499{
500 struct sta_info *sta;
501 unsigned long *aid_map;
502 int aid;
503
504 aid_map = bitmap_zalloc(IEEE80211_MAX_AID + 1, GFP_KERNEL);
505 if (!aid_map)
506 return -ENOMEM;
507
508 /* reserve aid 0 for mcast indication */
509 __set_bit(0, aid_map);
510
511 rcu_read_lock();
512 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list)
513 __set_bit(sta->sta.aid, aid_map);
514 rcu_read_unlock();
515
516 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1);
517 bitmap_free(aid_map);
518
519 if (aid > IEEE80211_MAX_AID)
520 return -ENOBUFS;
521
522 return aid;
523}
524
525static struct sta_info *
526__mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
527{
528 struct sta_info *sta;
529 int aid;
530
531 if (sdata->local->num_sta >= MESH_MAX_PLINKS)
532 return NULL;
533
534 aid = mesh_allocate_aid(sdata);
535 if (aid < 0)
536 return NULL;
537
538 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
539 if (!sta)
540 return NULL;
541
542 sta->mesh->plink_state = NL80211_PLINK_LISTEN;
543 sta->sta.wme = true;
544 sta->sta.aid = aid;
545
546 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
547 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
548 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
549
550 return sta;
551}
552
553static struct sta_info *
554mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
555 struct ieee802_11_elems *elems,
556 struct ieee80211_rx_status *rx_status)
557{
558 struct sta_info *sta = NULL;
559
560 /* Userspace handles station allocation */
561 if (sdata->u.mesh.user_mpm ||
562 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) {
563 if (mesh_peer_accepts_plinks(elems) &&
564 mesh_plink_availables(sdata)) {
565 int sig = 0;
566
567 if (ieee80211_hw_check(&sdata->local->hw, SIGNAL_DBM))
568 sig = rx_status->signal;
569
570 cfg80211_notify_new_peer_candidate(sdata->dev, addr,
571 elems->ie_start,
572 elems->total_len,
573 sig, GFP_KERNEL);
574 }
575 } else
576 sta = __mesh_sta_info_alloc(sdata, addr);
577
578 return sta;
579}
580
581/*
582 * mesh_sta_info_get - return mesh sta info entry for @addr.
583 *
584 * @sdata: local meshif
585 * @addr: peer's address
586 * @elems: IEs from beacon or mesh peering frame.
587 * @rx_status: rx status for the frame for signal reporting
588 *
589 * Return existing or newly allocated sta_info under RCU read lock.
590 * (re)initialize with given IEs.
591 */
592static struct sta_info *
593mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
594 u8 *addr, struct ieee802_11_elems *elems,
595 struct ieee80211_rx_status *rx_status) __acquires(RCU)
596{
597 struct sta_info *sta = NULL;
598
599 rcu_read_lock();
600 sta = sta_info_get(sdata, addr);
601 if (sta) {
602 mesh_sta_info_init(sdata, sta, elems);
603 } else {
604 rcu_read_unlock();
605 /* can't run atomic */
606 sta = mesh_sta_info_alloc(sdata, addr, elems, rx_status);
607 if (!sta) {
608 rcu_read_lock();
609 return NULL;
610 }
611
612 mesh_sta_info_init(sdata, sta, elems);
613
614 if (sta_info_insert_rcu(sta))
615 return NULL;
616 }
617
618 return sta;
619}
620
621/*
622 * mesh_neighbour_update - update or initialize new mesh neighbor.
623 *
624 * @sdata: local meshif
625 * @addr: peer's address
626 * @elems: IEs from beacon or mesh peering frame
627 * @rx_status: rx status for the frame for signal reporting
628 *
629 * Initiates peering if appropriate.
630 */
631void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
632 u8 *hw_addr,
633 struct ieee802_11_elems *elems,
634 struct ieee80211_rx_status *rx_status)
635{
636 struct sta_info *sta;
637 u64 changed = 0;
638
639 sta = mesh_sta_info_get(sdata, hw_addr, elems, rx_status);
640 if (!sta)
641 goto out;
642
643 sta->mesh->connected_to_gate = elems->mesh_config->meshconf_form &
644 IEEE80211_MESHCONF_FORM_CONNECTED_TO_GATE;
645
646 if (mesh_peer_accepts_plinks(elems) &&
647 sta->mesh->plink_state == NL80211_PLINK_LISTEN &&
648 sdata->u.mesh.accepting_plinks &&
649 sdata->u.mesh.mshcfg.auto_open_plinks &&
650 rssi_threshold_check(sdata, sta))
651 changed = mesh_plink_open(sta);
652
653 ieee80211_mps_frame_release(sta, elems);
654out:
655 rcu_read_unlock();
656 ieee80211_mbss_info_change_notify(sdata, changed);
657}
658
659void mesh_plink_timer(struct timer_list *t)
660{
661 struct mesh_sta *mesh = from_timer(mesh, t, plink_timer);
662 struct sta_info *sta;
663 u16 reason = 0;
664 struct ieee80211_sub_if_data *sdata;
665 struct mesh_config *mshcfg;
666 enum ieee80211_self_protected_actioncode action = 0;
667
668 /*
669 * This STA is valid because sta_info_destroy() will
670 * del_timer_sync() this timer after having made sure
671 * it cannot be re-added (by deleting the plink.)
672 */
673 sta = mesh->plink_sta;
674
675 if (sta->sdata->local->quiescing)
676 return;
677
678 spin_lock_bh(&sta->mesh->plink_lock);
679
680 /* If a timer fires just before a state transition on another CPU,
681 * we may have already extended the timeout and changed state by the
682 * time we've acquired the lock and arrived here. In that case,
683 * skip this timer and wait for the new one.
684 */
685 if (time_before(jiffies, sta->mesh->plink_timer.expires)) {
686 mpl_dbg(sta->sdata,
687 "Ignoring timer for %pM in state %s (timer adjusted)",
688 sta->sta.addr, mplstates[sta->mesh->plink_state]);
689 spin_unlock_bh(&sta->mesh->plink_lock);
690 return;
691 }
692
693 /* del_timer() and handler may race when entering these states */
694 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN ||
695 sta->mesh->plink_state == NL80211_PLINK_ESTAB) {
696 mpl_dbg(sta->sdata,
697 "Ignoring timer for %pM in state %s (timer deleted)",
698 sta->sta.addr, mplstates[sta->mesh->plink_state]);
699 spin_unlock_bh(&sta->mesh->plink_lock);
700 return;
701 }
702
703 mpl_dbg(sta->sdata,
704 "Mesh plink timer for %pM fired on state %s\n",
705 sta->sta.addr, mplstates[sta->mesh->plink_state]);
706 sdata = sta->sdata;
707 mshcfg = &sdata->u.mesh.mshcfg;
708
709 switch (sta->mesh->plink_state) {
710 case NL80211_PLINK_OPN_RCVD:
711 case NL80211_PLINK_OPN_SNT:
712 /* retry timer */
713 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) {
714 u32 rand;
715 mpl_dbg(sta->sdata,
716 "Mesh plink for %pM (retry, timeout): %d %d\n",
717 sta->sta.addr, sta->mesh->plink_retries,
718 sta->mesh->plink_timeout);
719 get_random_bytes(&rand, sizeof(u32));
720 sta->mesh->plink_timeout = sta->mesh->plink_timeout +
721 rand % sta->mesh->plink_timeout;
722 ++sta->mesh->plink_retries;
723 mod_plink_timer(sta, sta->mesh->plink_timeout);
724 action = WLAN_SP_MESH_PEERING_OPEN;
725 break;
726 }
727 reason = WLAN_REASON_MESH_MAX_RETRIES;
728 fallthrough;
729 case NL80211_PLINK_CNF_RCVD:
730 /* confirm timer */
731 if (!reason)
732 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT;
733 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
734 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
735 action = WLAN_SP_MESH_PEERING_CLOSE;
736 break;
737 case NL80211_PLINK_HOLDING:
738 /* holding timer */
739 del_timer(&sta->mesh->plink_timer);
740 mesh_plink_fsm_restart(sta);
741 break;
742 default:
743 break;
744 }
745 spin_unlock_bh(&sta->mesh->plink_lock);
746 if (action)
747 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
748 sta->mesh->llid, sta->mesh->plid, reason);
749}
750
751static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout)
752{
753 sta->mesh->plink_timeout = timeout;
754 mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout));
755}
756
757static bool llid_in_use(struct ieee80211_sub_if_data *sdata,
758 u16 llid)
759{
760 struct ieee80211_local *local = sdata->local;
761 bool in_use = false;
762 struct sta_info *sta;
763
764 rcu_read_lock();
765 list_for_each_entry_rcu(sta, &local->sta_list, list) {
766 if (sdata != sta->sdata)
767 continue;
768
769 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) {
770 in_use = true;
771 break;
772 }
773 }
774 rcu_read_unlock();
775
776 return in_use;
777}
778
779static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata)
780{
781 u16 llid;
782
783 do {
784 get_random_bytes(&llid, sizeof(llid));
785 } while (llid_in_use(sdata, llid));
786
787 return llid;
788}
789
790u64 mesh_plink_open(struct sta_info *sta)
791{
792 struct ieee80211_sub_if_data *sdata = sta->sdata;
793 u64 changed;
794
795 if (!test_sta_flag(sta, WLAN_STA_AUTH))
796 return 0;
797
798 spin_lock_bh(&sta->mesh->plink_lock);
799 sta->mesh->llid = mesh_get_new_llid(sdata);
800 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN &&
801 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) {
802 spin_unlock_bh(&sta->mesh->plink_lock);
803 return 0;
804 }
805 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT;
806 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
807 spin_unlock_bh(&sta->mesh->plink_lock);
808 mpl_dbg(sdata,
809 "Mesh plink: starting establishment with %pM\n",
810 sta->sta.addr);
811
812 /* set the non-peer mode to active during peering */
813 changed = ieee80211_mps_local_status_update(sdata);
814
815 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN,
816 sta->sta.addr, sta->mesh->llid, 0, 0);
817 return changed;
818}
819
820u64 mesh_plink_block(struct sta_info *sta)
821{
822 u64 changed;
823
824 spin_lock_bh(&sta->mesh->plink_lock);
825 changed = __mesh_plink_deactivate(sta);
826 sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
827 spin_unlock_bh(&sta->mesh->plink_lock);
828 mesh_path_flush_by_nexthop(sta);
829
830 return changed;
831}
832
833static void mesh_plink_close(struct ieee80211_sub_if_data *sdata,
834 struct sta_info *sta,
835 enum plink_event event)
836{
837 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
838 u16 reason = (event == CLS_ACPT) ?
839 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG;
840
841 sta->mesh->reason = reason;
842 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
843 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
844}
845
846static u64 mesh_plink_establish(struct ieee80211_sub_if_data *sdata,
847 struct sta_info *sta)
848{
849 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
850 u64 changed = 0;
851
852 del_timer(&sta->mesh->plink_timer);
853 sta->mesh->plink_state = NL80211_PLINK_ESTAB;
854 changed |= mesh_plink_inc_estab_count(sdata);
855 changed |= mesh_set_ht_prot_mode(sdata);
856 changed |= mesh_set_short_slot_time(sdata);
857 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr);
858 ieee80211_mps_sta_status_update(sta);
859 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode);
860 return changed;
861}
862
863/**
864 * mesh_plink_fsm - step @sta MPM based on @event
865 *
866 * @sdata: interface
867 * @sta: mesh neighbor
868 * @event: peering event
869 *
870 * Return: changed MBSS flags
871 */
872static u64 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata,
873 struct sta_info *sta, enum plink_event event)
874{
875 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
876 enum ieee80211_self_protected_actioncode action = 0;
877 u64 changed = 0;
878 bool flush = false;
879
880 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr,
881 mplstates[sta->mesh->plink_state], mplevents[event]);
882
883 spin_lock_bh(&sta->mesh->plink_lock);
884 switch (sta->mesh->plink_state) {
885 case NL80211_PLINK_LISTEN:
886 switch (event) {
887 case CLS_ACPT:
888 mesh_plink_fsm_restart(sta);
889 break;
890 case OPN_ACPT:
891 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
892 sta->mesh->llid = mesh_get_new_llid(sdata);
893 mesh_plink_timer_set(sta,
894 mshcfg->dot11MeshRetryTimeout);
895
896 /* set the non-peer mode to active during peering */
897 changed |= ieee80211_mps_local_status_update(sdata);
898 action = WLAN_SP_MESH_PEERING_OPEN;
899 break;
900 default:
901 break;
902 }
903 break;
904 case NL80211_PLINK_OPN_SNT:
905 switch (event) {
906 case OPN_RJCT:
907 case CNF_RJCT:
908 case CLS_ACPT:
909 mesh_plink_close(sdata, sta, event);
910 action = WLAN_SP_MESH_PEERING_CLOSE;
911 break;
912 case OPN_ACPT:
913 /* retry timer is left untouched */
914 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
915 action = WLAN_SP_MESH_PEERING_CONFIRM;
916 break;
917 case CNF_ACPT:
918 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD;
919 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout);
920 break;
921 default:
922 break;
923 }
924 break;
925 case NL80211_PLINK_OPN_RCVD:
926 switch (event) {
927 case OPN_RJCT:
928 case CNF_RJCT:
929 case CLS_ACPT:
930 mesh_plink_close(sdata, sta, event);
931 action = WLAN_SP_MESH_PEERING_CLOSE;
932 break;
933 case OPN_ACPT:
934 action = WLAN_SP_MESH_PEERING_CONFIRM;
935 break;
936 case CNF_ACPT:
937 changed |= mesh_plink_establish(sdata, sta);
938 break;
939 default:
940 break;
941 }
942 break;
943 case NL80211_PLINK_CNF_RCVD:
944 switch (event) {
945 case OPN_RJCT:
946 case CNF_RJCT:
947 case CLS_ACPT:
948 mesh_plink_close(sdata, sta, event);
949 action = WLAN_SP_MESH_PEERING_CLOSE;
950 break;
951 case OPN_ACPT:
952 changed |= mesh_plink_establish(sdata, sta);
953 action = WLAN_SP_MESH_PEERING_CONFIRM;
954 break;
955 default:
956 break;
957 }
958 break;
959 case NL80211_PLINK_ESTAB:
960 switch (event) {
961 case CLS_ACPT:
962 changed |= __mesh_plink_deactivate(sta);
963 changed |= mesh_set_ht_prot_mode(sdata);
964 changed |= mesh_set_short_slot_time(sdata);
965 mesh_plink_close(sdata, sta, event);
966 action = WLAN_SP_MESH_PEERING_CLOSE;
967 flush = true;
968 break;
969 case OPN_ACPT:
970 action = WLAN_SP_MESH_PEERING_CONFIRM;
971 break;
972 default:
973 break;
974 }
975 break;
976 case NL80211_PLINK_HOLDING:
977 switch (event) {
978 case CLS_ACPT:
979 del_timer(&sta->mesh->plink_timer);
980 mesh_plink_fsm_restart(sta);
981 break;
982 case OPN_ACPT:
983 case CNF_ACPT:
984 case OPN_RJCT:
985 case CNF_RJCT:
986 action = WLAN_SP_MESH_PEERING_CLOSE;
987 break;
988 default:
989 break;
990 }
991 break;
992 default:
993 /* should not get here, PLINK_BLOCKED is dealt with at the
994 * beginning of the function
995 */
996 break;
997 }
998 spin_unlock_bh(&sta->mesh->plink_lock);
999 if (flush)
1000 mesh_path_flush_by_nexthop(sta);
1001 if (action) {
1002 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
1003 sta->mesh->llid, sta->mesh->plid,
1004 sta->mesh->reason);
1005
1006 /* also send confirm in open case */
1007 if (action == WLAN_SP_MESH_PEERING_OPEN) {
1008 mesh_plink_frame_tx(sdata, sta,
1009 WLAN_SP_MESH_PEERING_CONFIRM,
1010 sta->sta.addr, sta->mesh->llid,
1011 sta->mesh->plid, 0);
1012 }
1013 }
1014
1015 return changed;
1016}
1017
1018/*
1019 * mesh_plink_get_event - get correct MPM event
1020 *
1021 * @sdata: interface
1022 * @sta: peer, leave NULL if processing a frame from a new suitable peer
1023 * @elems: peering management IEs
1024 * @ftype: frame type
1025 * @llid: peer's peer link ID
1026 * @plid: peer's local link ID
1027 *
1028 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as
1029 * an error.
1030 */
1031static enum plink_event
1032mesh_plink_get_event(struct ieee80211_sub_if_data *sdata,
1033 struct sta_info *sta,
1034 struct ieee802_11_elems *elems,
1035 enum ieee80211_self_protected_actioncode ftype,
1036 u16 llid, u16 plid)
1037{
1038 enum plink_event event = PLINK_UNDEFINED;
1039 u8 ie_len = elems->peering_len;
1040 bool matches_local;
1041
1042 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE ||
1043 mesh_matches_local(sdata, elems));
1044
1045 /* deny open request from non-matching peer */
1046 if (!matches_local && !sta) {
1047 event = OPN_RJCT;
1048 goto out;
1049 }
1050
1051 if (!sta) {
1052 if (ftype != WLAN_SP_MESH_PEERING_OPEN) {
1053 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
1054 goto out;
1055 }
1056 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
1057 if (!mesh_plink_free_count(sdata)) {
1058 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
1059 goto out;
1060 }
1061
1062 /* new matching peer */
1063 event = OPN_ACPT;
1064 goto out;
1065 } else {
1066 if (!test_sta_flag(sta, WLAN_STA_AUTH)) {
1067 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
1068 goto out;
1069 }
1070 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED)
1071 goto out;
1072 }
1073
1074 switch (ftype) {
1075 case WLAN_SP_MESH_PEERING_OPEN:
1076 if (!matches_local)
1077 event = OPN_RJCT;
1078 else if (!mesh_plink_free_count(sdata) ||
1079 (sta->mesh->plid && sta->mesh->plid != plid))
1080 event = OPN_IGNR;
1081 else
1082 event = OPN_ACPT;
1083 break;
1084 case WLAN_SP_MESH_PEERING_CONFIRM:
1085 if (!matches_local)
1086 event = CNF_RJCT;
1087 else if (!mesh_plink_free_count(sdata) ||
1088 sta->mesh->llid != llid ||
1089 (sta->mesh->plid && sta->mesh->plid != plid))
1090 event = CNF_IGNR;
1091 else
1092 event = CNF_ACPT;
1093 break;
1094 case WLAN_SP_MESH_PEERING_CLOSE:
1095 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
1096 /* Do not check for llid or plid. This does not
1097 * follow the standard but since multiple plinks
1098 * per sta are not supported, it is necessary in
1099 * order to avoid a livelock when MP A sees an
1100 * establish peer link to MP B but MP B does not
1101 * see it. This can be caused by a timeout in
1102 * B's peer link establishment or B beign
1103 * restarted.
1104 */
1105 event = CLS_ACPT;
1106 else if (sta->mesh->plid != plid)
1107 event = CLS_IGNR;
1108 else if (ie_len == 8 && sta->mesh->llid != llid)
1109 event = CLS_IGNR;
1110 else
1111 event = CLS_ACPT;
1112 break;
1113 default:
1114 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
1115 break;
1116 }
1117
1118out:
1119 return event;
1120}
1121
1122static void
1123mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
1124 struct ieee80211_mgmt *mgmt,
1125 struct ieee802_11_elems *elems,
1126 struct ieee80211_rx_status *rx_status)
1127{
1128
1129 struct sta_info *sta;
1130 enum plink_event event;
1131 enum ieee80211_self_protected_actioncode ftype;
1132 u64 changed = 0;
1133 u8 ie_len = elems->peering_len;
1134 u16 plid, llid = 0;
1135
1136 if (!elems->peering) {
1137 mpl_dbg(sdata,
1138 "Mesh plink: missing necessary peer link ie\n");
1139 return;
1140 }
1141
1142 if (elems->rsn_len &&
1143 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
1144 mpl_dbg(sdata,
1145 "Mesh plink: can't establish link with secure peer\n");
1146 return;
1147 }
1148
1149 ftype = mgmt->u.action.u.self_prot.action_code;
1150 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
1151 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
1152 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
1153 && ie_len != 8)) {
1154 mpl_dbg(sdata,
1155 "Mesh plink: incorrect plink ie length %d %d\n",
1156 ftype, ie_len);
1157 return;
1158 }
1159
1160 if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
1161 (!elems->mesh_id || !elems->mesh_config)) {
1162 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
1163 return;
1164 }
1165 /* Note the lines below are correct, the llid in the frame is the plid
1166 * from the point of view of this host.
1167 */
1168 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering));
1169 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
1170 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
1171 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering));
1172
1173 /* WARNING: Only for sta pointer, is dropped & re-acquired */
1174 rcu_read_lock();
1175
1176 sta = sta_info_get(sdata, mgmt->sa);
1177
1178 if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
1179 !rssi_threshold_check(sdata, sta)) {
1180 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
1181 mgmt->sa);
1182 goto unlock_rcu;
1183 }
1184
1185 /* Now we will figure out the appropriate event... */
1186 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid);
1187
1188 if (event == OPN_ACPT) {
1189 rcu_read_unlock();
1190 /* allocate sta entry if necessary and update info */
1191 sta = mesh_sta_info_get(sdata, mgmt->sa, elems, rx_status);
1192 if (!sta) {
1193 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
1194 goto unlock_rcu;
1195 }
1196 sta->mesh->plid = plid;
1197 } else if (!sta && event == OPN_RJCT) {
1198 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE,
1199 mgmt->sa, 0, plid,
1200 WLAN_REASON_MESH_CONFIG);
1201 goto unlock_rcu;
1202 } else if (!sta || event == PLINK_UNDEFINED) {
1203 /* something went wrong */
1204 goto unlock_rcu;
1205 }
1206
1207 if (event == CNF_ACPT) {
1208 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */
1209 if (!sta->mesh->plid)
1210 sta->mesh->plid = plid;
1211
1212 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt));
1213 }
1214
1215 changed |= mesh_plink_fsm(sdata, sta, event);
1216
1217unlock_rcu:
1218 rcu_read_unlock();
1219
1220 if (changed)
1221 ieee80211_mbss_info_change_notify(sdata, changed);
1222}
1223
1224void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
1225 struct ieee80211_mgmt *mgmt, size_t len,
1226 struct ieee80211_rx_status *rx_status)
1227{
1228 struct ieee802_11_elems *elems;
1229 size_t baselen;
1230 u8 *baseaddr;
1231
1232 /* need action_code, aux */
1233 if (len < IEEE80211_MIN_ACTION_SIZE + 3)
1234 return;
1235
1236 if (sdata->u.mesh.user_mpm)
1237 /* userspace must register for these */
1238 return;
1239
1240 if (is_multicast_ether_addr(mgmt->da)) {
1241 mpl_dbg(sdata,
1242 "Mesh plink: ignore frame from multicast address\n");
1243 return;
1244 }
1245
1246 baseaddr = mgmt->u.action.u.self_prot.variable;
1247 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
1248 if (mgmt->u.action.u.self_prot.action_code ==
1249 WLAN_SP_MESH_PEERING_CONFIRM) {
1250 baseaddr += 4;
1251 baselen += 4;
1252
1253 if (baselen > len)
1254 return;
1255 }
1256 elems = ieee802_11_parse_elems(baseaddr, len - baselen, true, NULL);
1257 if (elems) {
1258 mesh_process_plink_frame(sdata, mgmt, elems, rx_status);
1259 kfree(elems);
1260 }
1261}
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}