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Linux 5.7.7
[linux/fpc-iii.git] / net / mac80211 / mesh_plink.c
blob737c5f4dbf5201b4c408059e1223be66880ac8f1
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2008, 2009 open80211s Ltd.
4 * Copyright (C) 2019 Intel Corporation
5 * Author: Luis Carlos Cobo <luisca@cozybit.com>
6 */
7 #include <linux/gfp.h>
8 #include <linux/kernel.h>
9 #include <linux/random.h>
10 #include <linux/rculist.h>
11
12 #include "ieee80211_i.h"
13 #include "rate.h"
14 #include "mesh.h"
15
16 #define PLINK_CNF_AID(mgmt) ((mgmt)->u.action.u.self_prot.variable + 2)
17 #define PLINK_GET_LLID(p) (p + 2)
18 #define PLINK_GET_PLID(p) (p + 4)
19
20 #define mod_plink_timer(s, t) (mod_timer(&s->mesh->plink_timer, \
21 jiffies + msecs_to_jiffies(t)))
22
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->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 u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata)
94 {
95 struct ieee80211_local *local = sdata->local;
96 struct ieee80211_supported_band *sband;
97 struct sta_info *sta;
98 u32 erp_rates = 0, changed = 0;
99 int i;
100 bool short_slot = false;
101
102 sband = ieee80211_get_sband(sdata);
103 if (!sband)
104 return changed;
105
106 if (sband->band == NL80211_BAND_5GHZ) {
107 /* (IEEE 802.11-2012 19.4.5) */
108 short_slot = true;
109 goto out;
110 } else if (sband->band != NL80211_BAND_2GHZ) {
111 goto out;
112 }
113
114 for (i = 0; i < sband->n_bitrates; i++)
115 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)
116 erp_rates |= BIT(i);
117
118 if (!erp_rates)
119 goto out;
120
121 rcu_read_lock();
122 list_for_each_entry_rcu(sta, &local->sta_list, list) {
123 if (sdata != sta->sdata ||
124 sta->mesh->plink_state != NL80211_PLINK_ESTAB)
125 continue;
126
127 short_slot = false;
128 if (erp_rates & sta->sta.supp_rates[sband->band])
129 short_slot = true;
130 else
131 break;
132 }
133 rcu_read_unlock();
134
135 out:
136 if (sdata->vif.bss_conf.use_short_slot != short_slot) {
137 sdata->vif.bss_conf.use_short_slot = short_slot;
138 changed = BSS_CHANGED_ERP_SLOT;
139 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n",
140 sdata->vif.addr, short_slot);
141 }
142 return changed;
143 }
144
145 /**
146 * mesh_set_ht_prot_mode - set correct HT protection mode
147 *
148 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
149 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
150 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
151 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode
152 * is selected if all peers in our 20/40MHz MBSS support HT and atleast one
153 * HT20 peer is present. Otherwise no-protection mode is selected.
154 */
155 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
156 {
157 struct ieee80211_local *local = sdata->local;
158 struct sta_info *sta;
159 u16 ht_opmode;
160 bool non_ht_sta = false, ht20_sta = false;
161
162 switch (sdata->vif.bss_conf.chandef.width) {
163 case NL80211_CHAN_WIDTH_20_NOHT:
164 case NL80211_CHAN_WIDTH_5:
165 case NL80211_CHAN_WIDTH_10:
166 return 0;
167 default:
168 break;
169 }
170
171 rcu_read_lock();
172 list_for_each_entry_rcu(sta, &local->sta_list, list) {
173 if (sdata != sta->sdata ||
174 sta->mesh->plink_state != NL80211_PLINK_ESTAB)
175 continue;
176
177 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20)
178 continue;
179
180 if (!sta->sta.ht_cap.ht_supported) {
181 mpl_dbg(sdata, "nonHT sta (%pM) is present\n",
182 sta->sta.addr);
183 non_ht_sta = true;
184 break;
185 }
186
187 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr);
188 ht20_sta = true;
189 }
190 rcu_read_unlock();
191
192 if (non_ht_sta)
193 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
194 else if (ht20_sta &&
195 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20)
196 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
197 else
198 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
199
200 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode)
201 return 0;
202
203 sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
204 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
205 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode);
206 return BSS_CHANGED_HT;
207 }
208
209 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
210 struct sta_info *sta,
211 enum ieee80211_self_protected_actioncode action,
212 u8 *da, u16 llid, u16 plid, u16 reason)
213 {
214 struct ieee80211_local *local = sdata->local;
215 struct sk_buff *skb;
216 struct ieee80211_tx_info *info;
217 struct ieee80211_mgmt *mgmt;
218 bool include_plid = false;
219 u16 peering_proto = 0;
220 u8 *pos, ie_len = 4;
221 u8 ie_len_he_cap;
222 int hdr_len = offsetofend(struct ieee80211_mgmt, u.action.u.self_prot);
223 int err = -ENOMEM;
224
225 ie_len_he_cap = ieee80211_ie_len_he_cap(sdata,
226 NL80211_IFTYPE_MESH_POINT);
227 skb = dev_alloc_skb(local->tx_headroom +
228 hdr_len +
229 2 + /* capability info */
230 2 + /* AID */
231 2 + 8 + /* supported rates */
232 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
233 2 + sdata->u.mesh.mesh_id_len +
234 2 + sizeof(struct ieee80211_meshconf_ie) +
235 2 + sizeof(struct ieee80211_ht_cap) +
236 2 + sizeof(struct ieee80211_ht_operation) +
237 2 + sizeof(struct ieee80211_vht_cap) +
238 2 + sizeof(struct ieee80211_vht_operation) +
239 ie_len_he_cap +
240 2 + 1 + sizeof(struct ieee80211_he_operation) +
241 2 + 8 + /* peering IE */
242 sdata->u.mesh.ie_len);
243 if (!skb)
244 return err;
245 info = IEEE80211_SKB_CB(skb);
246 skb_reserve(skb, local->tx_headroom);
247 mgmt = skb_put_zero(skb, hdr_len);
248 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
249 IEEE80211_STYPE_ACTION);
250 memcpy(mgmt->da, da, ETH_ALEN);
251 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
252 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
253 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
254 mgmt->u.action.u.self_prot.action_code = action;
255
256 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
257 struct ieee80211_supported_band *sband;
258 enum nl80211_band band;
259
260 sband = ieee80211_get_sband(sdata);
261 if (!sband) {
262 err = -EINVAL;
263 goto free;
264 }
265 band = sband->band;
266
267 /* capability info */
268 pos = skb_put_zero(skb, 2);
269 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
270 /* AID */
271 pos = skb_put(skb, 2);
272 put_unaligned_le16(sta->sta.aid, pos);
273 }
274 if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
275 ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
276 mesh_add_rsn_ie(sdata, skb) ||
277 mesh_add_meshid_ie(sdata, skb) ||
278 mesh_add_meshconf_ie(sdata, skb))
279 goto free;
280 } else { /* WLAN_SP_MESH_PEERING_CLOSE */
281 info->flags |= IEEE80211_TX_CTL_NO_ACK;
282 if (mesh_add_meshid_ie(sdata, skb))
283 goto free;
284 }
285
286 /* Add Mesh Peering Management element */
287 switch (action) {
288 case WLAN_SP_MESH_PEERING_OPEN:
289 break;
290 case WLAN_SP_MESH_PEERING_CONFIRM:
291 ie_len += 2;
292 include_plid = true;
293 break;
294 case WLAN_SP_MESH_PEERING_CLOSE:
295 if (plid) {
296 ie_len += 2;
297 include_plid = true;
298 }
299 ie_len += 2; /* reason code */
300 break;
301 default:
302 err = -EINVAL;
303 goto free;
304 }
305
306 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
307 goto free;
308
309 pos = skb_put(skb, 2 + ie_len);
310 *pos++ = WLAN_EID_PEER_MGMT;
311 *pos++ = ie_len;
312 memcpy(pos, &peering_proto, 2);
313 pos += 2;
314 put_unaligned_le16(llid, pos);
315 pos += 2;
316 if (include_plid) {
317 put_unaligned_le16(plid, pos);
318 pos += 2;
319 }
320 if (action == WLAN_SP_MESH_PEERING_CLOSE) {
321 put_unaligned_le16(reason, pos);
322 pos += 2;
323 }
324
325 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
326 if (mesh_add_ht_cap_ie(sdata, skb) ||
327 mesh_add_ht_oper_ie(sdata, skb) ||
328 mesh_add_vht_cap_ie(sdata, skb) ||
329 mesh_add_vht_oper_ie(sdata, skb) ||
330 mesh_add_he_cap_ie(sdata, skb, ie_len_he_cap) ||
331 mesh_add_he_oper_ie(sdata, skb))
332 goto free;
333 }
334
335 if (mesh_add_vendor_ies(sdata, skb))
336 goto free;
337
338 ieee80211_tx_skb(sdata, skb);
339 return 0;
340 free:
341 kfree_skb(skb);
342 return err;
343 }
344
345 /**
346 * __mesh_plink_deactivate - deactivate mesh peer link
347 *
348 * @sta: mesh peer link to deactivate
349 *
350 * Mesh paths with this peer as next hop should be flushed
351 * by the caller outside of plink_lock.
352 *
353 * Returns beacon changed flag if the beacon content changed.
354 *
355 * Locking: the caller must hold sta->mesh->plink_lock
356 */
357 static u32 __mesh_plink_deactivate(struct sta_info *sta)
358 {
359 struct ieee80211_sub_if_data *sdata = sta->sdata;
360 u32 changed = 0;
361
362 lockdep_assert_held(&sta->mesh->plink_lock);
363
364 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
365 changed = mesh_plink_dec_estab_count(sdata);
366 sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
367
368 ieee80211_mps_sta_status_update(sta);
369 changed |= ieee80211_mps_set_sta_local_pm(sta,
370 NL80211_MESH_POWER_UNKNOWN);
371
372 return changed;
373 }
374
375 /**
376 * mesh_plink_deactivate - deactivate mesh peer link
377 *
378 * @sta: mesh peer link to deactivate
379 *
380 * All mesh paths with this peer as next hop will be flushed
381 */
382 u32 mesh_plink_deactivate(struct sta_info *sta)
383 {
384 struct ieee80211_sub_if_data *sdata = sta->sdata;
385 u32 changed;
386
387 spin_lock_bh(&sta->mesh->plink_lock);
388 changed = __mesh_plink_deactivate(sta);
389
390 if (!sdata->u.mesh.user_mpm) {
391 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED;
392 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE,
393 sta->sta.addr, sta->mesh->llid,
394 sta->mesh->plid, sta->mesh->reason);
395 }
396 spin_unlock_bh(&sta->mesh->plink_lock);
397 if (!sdata->u.mesh.user_mpm)
398 del_timer_sync(&sta->mesh->plink_timer);
399 mesh_path_flush_by_nexthop(sta);
400
401 /* make sure no readers can access nexthop sta from here on */
402 synchronize_net();
403
404 return changed;
405 }
406
407 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
408 struct sta_info *sta,
409 struct ieee802_11_elems *elems)
410 {
411 struct ieee80211_local *local = sdata->local;
412 struct ieee80211_supported_band *sband;
413 u32 rates, basic_rates = 0, changed = 0;
414 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth;
415
416 sband = ieee80211_get_sband(sdata);
417 if (!sband)
418 return;
419
420 rates = ieee80211_sta_get_rates(sdata, elems, sband->band,
421 &basic_rates);
422
423 spin_lock_bh(&sta->mesh->plink_lock);
424 sta->rx_stats.last_rx = jiffies;
425
426 /* rates and capabilities don't change during peering */
427 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB &&
428 sta->mesh->processed_beacon)
429 goto out;
430 sta->mesh->processed_beacon = true;
431
432 if (sta->sta.supp_rates[sband->band] != rates)
433 changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
434 sta->sta.supp_rates[sband->band] = rates;
435
436 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
437 elems->ht_cap_elem, sta))
438 changed |= IEEE80211_RC_BW_CHANGED;
439
440 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
441 elems->vht_cap_elem, sta);
442
443 ieee80211_he_cap_ie_to_sta_he_cap(sdata, sband, elems->he_cap,
444 elems->he_cap_len, sta);
445
446 if (bw != sta->sta.bandwidth)
447 changed |= IEEE80211_RC_BW_CHANGED;
448
449 /* HT peer is operating 20MHz-only */
450 if (elems->ht_operation &&
451 !(elems->ht_operation->ht_param &
452 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
453 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20)
454 changed |= IEEE80211_RC_BW_CHANGED;
455 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20;
456 }
457
458 if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
459 rate_control_rate_init(sta);
460 else
461 rate_control_rate_update(local, sband, sta, changed);
462 out:
463 spin_unlock_bh(&sta->mesh->plink_lock);
464 }
465
466 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata)
467 {
468 struct sta_info *sta;
469 unsigned long *aid_map;
470 int aid;
471
472 aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1),
473 sizeof(*aid_map), GFP_KERNEL);
474 if (!aid_map)
475 return -ENOMEM;
476
477 /* reserve aid 0 for mcast indication */
478 __set_bit(0, aid_map);
479
480 rcu_read_lock();
481 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list)
482 __set_bit(sta->sta.aid, aid_map);
483 rcu_read_unlock();
484
485 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1);
486 kfree(aid_map);
487
488 if (aid > IEEE80211_MAX_AID)
489 return -ENOBUFS;
490
491 return aid;
492 }
493
494 static struct sta_info *
495 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
496 {
497 struct sta_info *sta;
498 int aid;
499
500 if (sdata->local->num_sta >= MESH_MAX_PLINKS)
501 return NULL;
502
503 aid = mesh_allocate_aid(sdata);
504 if (aid < 0)
505 return NULL;
506
507 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
508 if (!sta)
509 return NULL;
510
511 sta->mesh->plink_state = NL80211_PLINK_LISTEN;
512 sta->sta.wme = true;
513 sta->sta.aid = aid;
514
515 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
516 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
517 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
518
519 return sta;
520 }
521
522 static struct sta_info *
523 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
524 struct ieee802_11_elems *elems,
525 struct ieee80211_rx_status *rx_status)
526 {
527 struct sta_info *sta = NULL;
528
529 /* Userspace handles station allocation */
530 if (sdata->u.mesh.user_mpm ||
531 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) {
532 if (mesh_peer_accepts_plinks(elems) &&
533 mesh_plink_availables(sdata)) {
534 int sig = 0;
535
536 if (ieee80211_hw_check(&sdata->local->hw, SIGNAL_DBM))
537 sig = rx_status->signal;
538
539 cfg80211_notify_new_peer_candidate(sdata->dev, addr,
540 elems->ie_start,
541 elems->total_len,
542 sig, GFP_KERNEL);
543 }
544 } else
545 sta = __mesh_sta_info_alloc(sdata, addr);
546
547 return sta;
548 }
549
550 /*
551 * mesh_sta_info_get - return mesh sta info entry for @addr.
552 *
553 * @sdata: local meshif
554 * @addr: peer's address
555 * @elems: IEs from beacon or mesh peering frame.
556 * @rx_status: rx status for the frame for signal reporting
557 *
558 * Return existing or newly allocated sta_info under RCU read lock.
559 * (re)initialize with given IEs.
560 */
561 static struct sta_info *
562 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
563 u8 *addr, struct ieee802_11_elems *elems,
564 struct ieee80211_rx_status *rx_status) __acquires(RCU)
565 {
566 struct sta_info *sta = NULL;
567
568 rcu_read_lock();
569 sta = sta_info_get(sdata, addr);
570 if (sta) {
571 mesh_sta_info_init(sdata, sta, elems);
572 } else {
573 rcu_read_unlock();
574 /* can't run atomic */
575 sta = mesh_sta_info_alloc(sdata, addr, elems, rx_status);
576 if (!sta) {
577 rcu_read_lock();
578 return NULL;
579 }
580
581 mesh_sta_info_init(sdata, sta, elems);
582
583 if (sta_info_insert_rcu(sta))
584 return NULL;
585 }
586
587 return sta;
588 }
589
590 /*
591 * mesh_neighbour_update - update or initialize new mesh neighbor.
592 *
593 * @sdata: local meshif
594 * @addr: peer's address
595 * @elems: IEs from beacon or mesh peering frame
596 * @rx_status: rx status for the frame for signal reporting
597 *
598 * Initiates peering if appropriate.
599 */
600 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
601 u8 *hw_addr,
602 struct ieee802_11_elems *elems,
603 struct ieee80211_rx_status *rx_status)
604 {
605 struct sta_info *sta;
606 u32 changed = 0;
607
608 sta = mesh_sta_info_get(sdata, hw_addr, elems, rx_status);
609 if (!sta)
610 goto out;
611
612 sta->mesh->connected_to_gate = elems->mesh_config->meshconf_form &
613 IEEE80211_MESHCONF_FORM_CONNECTED_TO_GATE;
614
615 if (mesh_peer_accepts_plinks(elems) &&
616 sta->mesh->plink_state == NL80211_PLINK_LISTEN &&
617 sdata->u.mesh.accepting_plinks &&
618 sdata->u.mesh.mshcfg.auto_open_plinks &&
619 rssi_threshold_check(sdata, sta))
620 changed = mesh_plink_open(sta);
621
622 ieee80211_mps_frame_release(sta, elems);
623 out:
624 rcu_read_unlock();
625 ieee80211_mbss_info_change_notify(sdata, changed);
626 }
627
628 void mesh_plink_timer(struct timer_list *t)
629 {
630 struct mesh_sta *mesh = from_timer(mesh, t, plink_timer);
631 struct sta_info *sta;
632 u16 reason = 0;
633 struct ieee80211_sub_if_data *sdata;
634 struct mesh_config *mshcfg;
635 enum ieee80211_self_protected_actioncode action = 0;
636
637 /*
638 * This STA is valid because sta_info_destroy() will
639 * del_timer_sync() this timer after having made sure
640 * it cannot be readded (by deleting the plink.)
641 */
642 sta = mesh->plink_sta;
643
644 if (sta->sdata->local->quiescing)
645 return;
646
647 spin_lock_bh(&sta->mesh->plink_lock);
648
649 /* If a timer fires just before a state transition on another CPU,
650 * we may have already extended the timeout and changed state by the
651 * time we've acquired the lock and arrived here. In that case,
652 * skip this timer and wait for the new one.
653 */
654 if (time_before(jiffies, sta->mesh->plink_timer.expires)) {
655 mpl_dbg(sta->sdata,
656 "Ignoring timer for %pM in state %s (timer adjusted)",
657 sta->sta.addr, mplstates[sta->mesh->plink_state]);
658 spin_unlock_bh(&sta->mesh->plink_lock);
659 return;
660 }
661
662 /* del_timer() and handler may race when entering these states */
663 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN ||
664 sta->mesh->plink_state == NL80211_PLINK_ESTAB) {
665 mpl_dbg(sta->sdata,
666 "Ignoring timer for %pM in state %s (timer deleted)",
667 sta->sta.addr, mplstates[sta->mesh->plink_state]);
668 spin_unlock_bh(&sta->mesh->plink_lock);
669 return;
670 }
671
672 mpl_dbg(sta->sdata,
673 "Mesh plink timer for %pM fired on state %s\n",
674 sta->sta.addr, mplstates[sta->mesh->plink_state]);
675 sdata = sta->sdata;
676 mshcfg = &sdata->u.mesh.mshcfg;
677
678 switch (sta->mesh->plink_state) {
679 case NL80211_PLINK_OPN_RCVD:
680 case NL80211_PLINK_OPN_SNT:
681 /* retry timer */
682 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) {
683 u32 rand;
684 mpl_dbg(sta->sdata,
685 "Mesh plink for %pM (retry, timeout): %d %d\n",
686 sta->sta.addr, sta->mesh->plink_retries,
687 sta->mesh->plink_timeout);
688 get_random_bytes(&rand, sizeof(u32));
689 sta->mesh->plink_timeout = sta->mesh->plink_timeout +
690 rand % sta->mesh->plink_timeout;
691 ++sta->mesh->plink_retries;
692 mod_plink_timer(sta, sta->mesh->plink_timeout);
693 action = WLAN_SP_MESH_PEERING_OPEN;
694 break;
695 }
696 reason = WLAN_REASON_MESH_MAX_RETRIES;
697 /* fall through */
698 case NL80211_PLINK_CNF_RCVD:
699 /* confirm timer */
700 if (!reason)
701 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT;
702 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
703 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
704 action = WLAN_SP_MESH_PEERING_CLOSE;
705 break;
706 case NL80211_PLINK_HOLDING:
707 /* holding timer */
708 del_timer(&sta->mesh->plink_timer);
709 mesh_plink_fsm_restart(sta);
710 break;
711 default:
712 break;
713 }
714 spin_unlock_bh(&sta->mesh->plink_lock);
715 if (action)
716 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
717 sta->mesh->llid, sta->mesh->plid, reason);
718 }
719
720 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout)
721 {
722 sta->mesh->plink_timeout = timeout;
723 mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout));
724 }
725
726 static bool llid_in_use(struct ieee80211_sub_if_data *sdata,
727 u16 llid)
728 {
729 struct ieee80211_local *local = sdata->local;
730 bool in_use = false;
731 struct sta_info *sta;
732
733 rcu_read_lock();
734 list_for_each_entry_rcu(sta, &local->sta_list, list) {
735 if (sdata != sta->sdata)
736 continue;
737
738 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) {
739 in_use = true;
740 break;
741 }
742 }
743 rcu_read_unlock();
744
745 return in_use;
746 }
747
748 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata)
749 {
750 u16 llid;
751
752 do {
753 get_random_bytes(&llid, sizeof(llid));
754 } while (llid_in_use(sdata, llid));
755
756 return llid;
757 }
758
759 u32 mesh_plink_open(struct sta_info *sta)
760 {
761 struct ieee80211_sub_if_data *sdata = sta->sdata;
762 u32 changed;
763
764 if (!test_sta_flag(sta, WLAN_STA_AUTH))
765 return 0;
766
767 spin_lock_bh(&sta->mesh->plink_lock);
768 sta->mesh->llid = mesh_get_new_llid(sdata);
769 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN &&
770 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) {
771 spin_unlock_bh(&sta->mesh->plink_lock);
772 return 0;
773 }
774 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT;
775 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
776 spin_unlock_bh(&sta->mesh->plink_lock);
777 mpl_dbg(sdata,
778 "Mesh plink: starting establishment with %pM\n",
779 sta->sta.addr);
780
781 /* set the non-peer mode to active during peering */
782 changed = ieee80211_mps_local_status_update(sdata);
783
784 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN,
785 sta->sta.addr, sta->mesh->llid, 0, 0);
786 return changed;
787 }
788
789 u32 mesh_plink_block(struct sta_info *sta)
790 {
791 u32 changed;
792
793 spin_lock_bh(&sta->mesh->plink_lock);
794 changed = __mesh_plink_deactivate(sta);
795 sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
796 spin_unlock_bh(&sta->mesh->plink_lock);
797 mesh_path_flush_by_nexthop(sta);
798
799 return changed;
800 }
801
802 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata,
803 struct sta_info *sta,
804 enum plink_event event)
805 {
806 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
807 u16 reason = (event == CLS_ACPT) ?
808 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG;
809
810 sta->mesh->reason = reason;
811 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
812 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
813 }
814
815 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata,
816 struct sta_info *sta)
817 {
818 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
819 u32 changed = 0;
820
821 del_timer(&sta->mesh->plink_timer);
822 sta->mesh->plink_state = NL80211_PLINK_ESTAB;
823 changed |= mesh_plink_inc_estab_count(sdata);
824 changed |= mesh_set_ht_prot_mode(sdata);
825 changed |= mesh_set_short_slot_time(sdata);
826 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr);
827 ieee80211_mps_sta_status_update(sta);
828 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode);
829 return changed;
830 }
831
832 /**
833 * mesh_plink_fsm - step @sta MPM based on @event
834 *
835 * @sdata: interface
836 * @sta: mesh neighbor
837 * @event: peering event
838 *
839 * Return: changed MBSS flags
840 */
841 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata,
842 struct sta_info *sta, enum plink_event event)
843 {
844 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
845 enum ieee80211_self_protected_actioncode action = 0;
846 u32 changed = 0;
847 bool flush = false;
848
849 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr,
850 mplstates[sta->mesh->plink_state], mplevents[event]);
851
852 spin_lock_bh(&sta->mesh->plink_lock);
853 switch (sta->mesh->plink_state) {
854 case NL80211_PLINK_LISTEN:
855 switch (event) {
856 case CLS_ACPT:
857 mesh_plink_fsm_restart(sta);
858 break;
859 case OPN_ACPT:
860 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
861 sta->mesh->llid = mesh_get_new_llid(sdata);
862 mesh_plink_timer_set(sta,
863 mshcfg->dot11MeshRetryTimeout);
864
865 /* set the non-peer mode to active during peering */
866 changed |= ieee80211_mps_local_status_update(sdata);
867 action = WLAN_SP_MESH_PEERING_OPEN;
868 break;
869 default:
870 break;
871 }
872 break;
873 case NL80211_PLINK_OPN_SNT:
874 switch (event) {
875 case OPN_RJCT:
876 case CNF_RJCT:
877 case CLS_ACPT:
878 mesh_plink_close(sdata, sta, event);
879 action = WLAN_SP_MESH_PEERING_CLOSE;
880 break;
881 case OPN_ACPT:
882 /* retry timer is left untouched */
883 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
884 action = WLAN_SP_MESH_PEERING_CONFIRM;
885 break;
886 case CNF_ACPT:
887 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD;
888 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout);
889 break;
890 default:
891 break;
892 }
893 break;
894 case NL80211_PLINK_OPN_RCVD:
895 switch (event) {
896 case OPN_RJCT:
897 case CNF_RJCT:
898 case CLS_ACPT:
899 mesh_plink_close(sdata, sta, event);
900 action = WLAN_SP_MESH_PEERING_CLOSE;
901 break;
902 case OPN_ACPT:
903 action = WLAN_SP_MESH_PEERING_CONFIRM;
904 break;
905 case CNF_ACPT:
906 changed |= mesh_plink_establish(sdata, sta);
907 break;
908 default:
909 break;
910 }
911 break;
912 case NL80211_PLINK_CNF_RCVD:
913 switch (event) {
914 case OPN_RJCT:
915 case CNF_RJCT:
916 case CLS_ACPT:
917 mesh_plink_close(sdata, sta, event);
918 action = WLAN_SP_MESH_PEERING_CLOSE;
919 break;
920 case OPN_ACPT:
921 changed |= mesh_plink_establish(sdata, sta);
922 action = WLAN_SP_MESH_PEERING_CONFIRM;
923 break;
924 default:
925 break;
926 }
927 break;
928 case NL80211_PLINK_ESTAB:
929 switch (event) {
930 case CLS_ACPT:
931 changed |= __mesh_plink_deactivate(sta);
932 changed |= mesh_set_ht_prot_mode(sdata);
933 changed |= mesh_set_short_slot_time(sdata);
934 mesh_plink_close(sdata, sta, event);
935 action = WLAN_SP_MESH_PEERING_CLOSE;
936 flush = true;
937 break;
938 case OPN_ACPT:
939 action = WLAN_SP_MESH_PEERING_CONFIRM;
940 break;
941 default:
942 break;
943 }
944 break;
945 case NL80211_PLINK_HOLDING:
946 switch (event) {
947 case CLS_ACPT:
948 del_timer(&sta->mesh->plink_timer);
949 mesh_plink_fsm_restart(sta);
950 break;
951 case OPN_ACPT:
952 case CNF_ACPT:
953 case OPN_RJCT:
954 case CNF_RJCT:
955 action = WLAN_SP_MESH_PEERING_CLOSE;
956 break;
957 default:
958 break;
959 }
960 break;
961 default:
962 /* should not get here, PLINK_BLOCKED is dealt with at the
963 * beginning of the function
964 */
965 break;
966 }
967 spin_unlock_bh(&sta->mesh->plink_lock);
968 if (flush)
969 mesh_path_flush_by_nexthop(sta);
970 if (action) {
971 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
972 sta->mesh->llid, sta->mesh->plid,
973 sta->mesh->reason);
974
975 /* also send confirm in open case */
976 if (action == WLAN_SP_MESH_PEERING_OPEN) {
977 mesh_plink_frame_tx(sdata, sta,
978 WLAN_SP_MESH_PEERING_CONFIRM,
979 sta->sta.addr, sta->mesh->llid,
980 sta->mesh->plid, 0);
981 }
982 }
983
984 return changed;
985 }
986
987 /*
988 * mesh_plink_get_event - get correct MPM event
989 *
990 * @sdata: interface
991 * @sta: peer, leave NULL if processing a frame from a new suitable peer
992 * @elems: peering management IEs
993 * @ftype: frame type
994 * @llid: peer's peer link ID
995 * @plid: peer's local link ID
996 *
997 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as
998 * an error.
999 */
1000 static enum plink_event
1001 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata,
1002 struct sta_info *sta,
1003 struct ieee802_11_elems *elems,
1004 enum ieee80211_self_protected_actioncode ftype,
1005 u16 llid, u16 plid)
1006 {
1007 enum plink_event event = PLINK_UNDEFINED;
1008 u8 ie_len = elems->peering_len;
1009 bool matches_local;
1010
1011 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE ||
1012 mesh_matches_local(sdata, elems));
1013
1014 /* deny open request from non-matching peer */
1015 if (!matches_local && !sta) {
1016 event = OPN_RJCT;
1017 goto out;
1018 }
1019
1020 if (!sta) {
1021 if (ftype != WLAN_SP_MESH_PEERING_OPEN) {
1022 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
1023 goto out;
1024 }
1025 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
1026 if (!mesh_plink_free_count(sdata)) {
1027 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
1028 goto out;
1029 }
1030
1031 /* new matching peer */
1032 event = OPN_ACPT;
1033 goto out;
1034 } else {
1035 if (!test_sta_flag(sta, WLAN_STA_AUTH)) {
1036 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
1037 goto out;
1038 }
1039 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED)
1040 goto out;
1041 }
1042
1043 switch (ftype) {
1044 case WLAN_SP_MESH_PEERING_OPEN:
1045 if (!matches_local)
1046 event = OPN_RJCT;
1047 if (!mesh_plink_free_count(sdata) ||
1048 (sta->mesh->plid && sta->mesh->plid != plid))
1049 event = OPN_IGNR;
1050 else
1051 event = OPN_ACPT;
1052 break;
1053 case WLAN_SP_MESH_PEERING_CONFIRM:
1054 if (!matches_local)
1055 event = CNF_RJCT;
1056 if (!mesh_plink_free_count(sdata) ||
1057 sta->mesh->llid != llid ||
1058 (sta->mesh->plid && sta->mesh->plid != plid))
1059 event = CNF_IGNR;
1060 else
1061 event = CNF_ACPT;
1062 break;
1063 case WLAN_SP_MESH_PEERING_CLOSE:
1064 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
1065 /* Do not check for llid or plid. This does not
1066 * follow the standard but since multiple plinks
1067 * per sta are not supported, it is necessary in
1068 * order to avoid a livelock when MP A sees an
1069 * establish peer link to MP B but MP B does not
1070 * see it. This can be caused by a timeout in
1071 * B's peer link establishment or B beign
1072 * restarted.
1073 */
1074 event = CLS_ACPT;
1075 else if (sta->mesh->plid != plid)
1076 event = CLS_IGNR;
1077 else if (ie_len == 8 && sta->mesh->llid != llid)
1078 event = CLS_IGNR;
1079 else
1080 event = CLS_ACPT;
1081 break;
1082 default:
1083 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
1084 break;
1085 }
1086
1087 out:
1088 return event;
1089 }
1090
1091 static void
1092 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
1093 struct ieee80211_mgmt *mgmt,
1094 struct ieee802_11_elems *elems,
1095 struct ieee80211_rx_status *rx_status)
1096 {
1097
1098 struct sta_info *sta;
1099 enum plink_event event;
1100 enum ieee80211_self_protected_actioncode ftype;
1101 u32 changed = 0;
1102 u8 ie_len = elems->peering_len;
1103 u16 plid, llid = 0;
1104
1105 if (!elems->peering) {
1106 mpl_dbg(sdata,
1107 "Mesh plink: missing necessary peer link ie\n");
1108 return;
1109 }
1110
1111 if (elems->rsn_len &&
1112 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
1113 mpl_dbg(sdata,
1114 "Mesh plink: can't establish link with secure peer\n");
1115 return;
1116 }
1117
1118 ftype = mgmt->u.action.u.self_prot.action_code;
1119 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
1120 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
1121 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
1122 && ie_len != 8)) {
1123 mpl_dbg(sdata,
1124 "Mesh plink: incorrect plink ie length %d %d\n",
1125 ftype, ie_len);
1126 return;
1127 }
1128
1129 if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
1130 (!elems->mesh_id || !elems->mesh_config)) {
1131 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
1132 return;
1133 }
1134 /* Note the lines below are correct, the llid in the frame is the plid
1135 * from the point of view of this host.
1136 */
1137 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering));
1138 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
1139 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
1140 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering));
1141
1142 /* WARNING: Only for sta pointer, is dropped & re-acquired */
1143 rcu_read_lock();
1144
1145 sta = sta_info_get(sdata, mgmt->sa);
1146
1147 if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
1148 !rssi_threshold_check(sdata, sta)) {
1149 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
1150 mgmt->sa);
1151 goto unlock_rcu;
1152 }
1153
1154 /* Now we will figure out the appropriate event... */
1155 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid);
1156
1157 if (event == OPN_ACPT) {
1158 rcu_read_unlock();
1159 /* allocate sta entry if necessary and update info */
1160 sta = mesh_sta_info_get(sdata, mgmt->sa, elems, rx_status);
1161 if (!sta) {
1162 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
1163 goto unlock_rcu;
1164 }
1165 sta->mesh->plid = plid;
1166 } else if (!sta && event == OPN_RJCT) {
1167 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE,
1168 mgmt->sa, 0, plid,
1169 WLAN_REASON_MESH_CONFIG);
1170 goto unlock_rcu;
1171 } else if (!sta || event == PLINK_UNDEFINED) {
1172 /* something went wrong */
1173 goto unlock_rcu;
1174 }
1175
1176 if (event == CNF_ACPT) {
1177 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */
1178 if (!sta->mesh->plid)
1179 sta->mesh->plid = plid;
1180
1181 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt));
1182 }
1183
1184 changed |= mesh_plink_fsm(sdata, sta, event);
1185
1186 unlock_rcu:
1187 rcu_read_unlock();
1188
1189 if (changed)
1190 ieee80211_mbss_info_change_notify(sdata, changed);
1191 }
1192
1193 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
1194 struct ieee80211_mgmt *mgmt, size_t len,
1195 struct ieee80211_rx_status *rx_status)
1196 {
1197 struct ieee802_11_elems elems;
1198 size_t baselen;
1199 u8 *baseaddr;
1200
1201 /* need action_code, aux */
1202 if (len < IEEE80211_MIN_ACTION_SIZE + 3)
1203 return;
1204
1205 if (sdata->u.mesh.user_mpm)
1206 /* userspace must register for these */
1207 return;
1208
1209 if (is_multicast_ether_addr(mgmt->da)) {
1210 mpl_dbg(sdata,
1211 "Mesh plink: ignore frame from multicast address\n");
1212 return;
1213 }
1214
1215 baseaddr = mgmt->u.action.u.self_prot.variable;
1216 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
1217 if (mgmt->u.action.u.self_prot.action_code ==
1218 WLAN_SP_MESH_PEERING_CONFIRM) {
1219 baseaddr += 4;
1220 baselen += 4;
1221
1222 if (baselen > len)
1223 return;
1224 }
1225 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems,
1226 mgmt->bssid, NULL);
1227 mesh_process_plink_frame(sdata, mgmt, &elems, rx_status);
1228 }
Linux with added FPC-III support