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Linux 4.11.6
[linux/fpc-iii.git] / net / mac80211 / mesh_plink.c
blob953d71e784a9ab71cb8494478e39eaf3b9464211
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 <linux/rculist.h>
13
14 #include "ieee80211_i.h"
15 #include "rate.h"
16 #include "mesh.h"
17
18 #define PLINK_CNF_AID(mgmt) ((mgmt)->u.action.u.self_prot.variable + 2)
19 #define PLINK_GET_LLID(p) (p + 2)
20 #define PLINK_GET_PLID(p) (p + 4)
21
22 #define mod_plink_timer(s, t) (mod_timer(&s->mesh->plink_timer, \
23 jiffies + msecs_to_jiffies(t)))
24
25 enum plink_event {
26 PLINK_UNDEFINED,
27 OPN_ACPT,
28 OPN_RJCT,
29 OPN_IGNR,
30 CNF_ACPT,
31 CNF_RJCT,
32 CNF_IGNR,
33 CLS_ACPT,
34 CLS_IGNR
35 };
36
37 static const char * const mplstates[] = {
38 [NL80211_PLINK_LISTEN] = "LISTEN",
39 [NL80211_PLINK_OPN_SNT] = "OPN-SNT",
40 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
41 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
42 [NL80211_PLINK_ESTAB] = "ESTAB",
43 [NL80211_PLINK_HOLDING] = "HOLDING",
44 [NL80211_PLINK_BLOCKED] = "BLOCKED"
45 };
46
47 static const char * const mplevents[] = {
48 [PLINK_UNDEFINED] = "NONE",
49 [OPN_ACPT] = "OPN_ACPT",
50 [OPN_RJCT] = "OPN_RJCT",
51 [OPN_IGNR] = "OPN_IGNR",
52 [CNF_ACPT] = "CNF_ACPT",
53 [CNF_RJCT] = "CNF_RJCT",
54 [CNF_IGNR] = "CNF_IGNR",
55 [CLS_ACPT] = "CLS_ACPT",
56 [CLS_IGNR] = "CLS_IGNR"
57 };
58
59 /* We only need a valid sta if user configured a minimum rssi_threshold. */
60 static bool rssi_threshold_check(struct ieee80211_sub_if_data *sdata,
61 struct sta_info *sta)
62 {
63 s32 rssi_threshold = sdata->u.mesh.mshcfg.rssi_threshold;
64 return rssi_threshold == 0 ||
65 (sta &&
66 (s8)-ewma_signal_read(&sta->rx_stats_avg.signal) >
67 rssi_threshold);
68 }
69
70 /**
71 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
72 *
73 * @sta: mesh peer link to restart
74 *
75 * Locking: this function must be called holding sta->mesh->plink_lock
76 */
77 static inline void mesh_plink_fsm_restart(struct sta_info *sta)
78 {
79 lockdep_assert_held(&sta->mesh->plink_lock);
80 sta->mesh->plink_state = NL80211_PLINK_LISTEN;
81 sta->mesh->llid = sta->mesh->plid = sta->mesh->reason = 0;
82 sta->mesh->plink_retries = 0;
83 }
84
85 /*
86 * mesh_set_short_slot_time - enable / disable ERP short slot time.
87 *
88 * The standard indirectly mandates mesh STAs to turn off short slot time by
89 * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we
90 * can't be sneaky about it. Enable short slot time if all mesh STAs in the
91 * MBSS support ERP rates.
92 *
93 * Returns BSS_CHANGED_ERP_SLOT or 0 for no change.
94 */
95 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata)
96 {
97 struct ieee80211_local *local = sdata->local;
98 enum nl80211_band band = ieee80211_get_sdata_band(sdata);
99 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
100 struct sta_info *sta;
101 u32 erp_rates = 0, changed = 0;
102 int i;
103 bool short_slot = false;
104
105 if (band == NL80211_BAND_5GHZ) {
106 /* (IEEE 802.11-2012 19.4.5) */
107 short_slot = true;
108 goto out;
109 } else if (band != NL80211_BAND_2GHZ)
110 goto out;
111
112 for (i = 0; i < sband->n_bitrates; i++)
113 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)
114 erp_rates |= BIT(i);
115
116 if (!erp_rates)
117 goto out;
118
119 rcu_read_lock();
120 list_for_each_entry_rcu(sta, &local->sta_list, list) {
121 if (sdata != sta->sdata ||
122 sta->mesh->plink_state != NL80211_PLINK_ESTAB)
123 continue;
124
125 short_slot = false;
126 if (erp_rates & sta->sta.supp_rates[band])
127 short_slot = true;
128 else
129 break;
130 }
131 rcu_read_unlock();
132
133 out:
134 if (sdata->vif.bss_conf.use_short_slot != short_slot) {
135 sdata->vif.bss_conf.use_short_slot = short_slot;
136 changed = BSS_CHANGED_ERP_SLOT;
137 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n",
138 sdata->vif.addr, short_slot);
139 }
140 return changed;
141 }
142
143 /**
144 * mesh_set_ht_prot_mode - set correct HT protection mode
145 *
146 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
147 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
148 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
149 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode
150 * is selected if all peers in our 20/40MHz MBSS support HT and atleast one
151 * HT20 peer is present. Otherwise no-protection mode is selected.
152 */
153 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
154 {
155 struct ieee80211_local *local = sdata->local;
156 struct sta_info *sta;
157 u16 ht_opmode;
158 bool non_ht_sta = false, ht20_sta = false;
159
160 switch (sdata->vif.bss_conf.chandef.width) {
161 case NL80211_CHAN_WIDTH_20_NOHT:
162 case NL80211_CHAN_WIDTH_5:
163 case NL80211_CHAN_WIDTH_10:
164 return 0;
165 default:
166 break;
167 }
168
169 rcu_read_lock();
170 list_for_each_entry_rcu(sta, &local->sta_list, list) {
171 if (sdata != sta->sdata ||
172 sta->mesh->plink_state != NL80211_PLINK_ESTAB)
173 continue;
174
175 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20)
176 continue;
177
178 if (!sta->sta.ht_cap.ht_supported) {
179 mpl_dbg(sdata, "nonHT sta (%pM) is present\n",
180 sta->sta.addr);
181 non_ht_sta = true;
182 break;
183 }
184
185 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr);
186 ht20_sta = true;
187 }
188 rcu_read_unlock();
189
190 if (non_ht_sta)
191 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
192 else if (ht20_sta &&
193 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20)
194 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
195 else
196 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
197
198 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode)
199 return 0;
200
201 sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
202 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
203 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode);
204 return BSS_CHANGED_HT;
205 }
206
207 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
208 struct sta_info *sta,
209 enum ieee80211_self_protected_actioncode action,
210 u8 *da, u16 llid, u16 plid, u16 reason)
211 {
212 struct ieee80211_local *local = sdata->local;
213 struct sk_buff *skb;
214 struct ieee80211_tx_info *info;
215 struct ieee80211_mgmt *mgmt;
216 bool include_plid = false;
217 u16 peering_proto = 0;
218 u8 *pos, ie_len = 4;
219 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) +
220 sizeof(mgmt->u.action.u.self_prot);
221 int err = -ENOMEM;
222
223 skb = dev_alloc_skb(local->tx_headroom +
224 hdr_len +
225 2 + /* capability info */
226 2 + /* AID */
227 2 + 8 + /* supported rates */
228 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
229 2 + sdata->u.mesh.mesh_id_len +
230 2 + sizeof(struct ieee80211_meshconf_ie) +
231 2 + sizeof(struct ieee80211_ht_cap) +
232 2 + sizeof(struct ieee80211_ht_operation) +
233 2 + sizeof(struct ieee80211_vht_cap) +
234 2 + sizeof(struct ieee80211_vht_operation) +
235 2 + 8 + /* peering IE */
236 sdata->u.mesh.ie_len);
237 if (!skb)
238 return err;
239 info = IEEE80211_SKB_CB(skb);
240 skb_reserve(skb, local->tx_headroom);
241 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
242 memset(mgmt, 0, hdr_len);
243 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
244 IEEE80211_STYPE_ACTION);
245 memcpy(mgmt->da, da, ETH_ALEN);
246 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
247 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
248 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
249 mgmt->u.action.u.self_prot.action_code = action;
250
251 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
252 enum nl80211_band band = ieee80211_get_sdata_band(sdata);
253
254 /* capability info */
255 pos = skb_put(skb, 2);
256 memset(pos, 0, 2);
257 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
258 /* AID */
259 pos = skb_put(skb, 2);
260 put_unaligned_le16(sta->sta.aid, pos);
261 }
262 if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
263 ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
264 mesh_add_rsn_ie(sdata, skb) ||
265 mesh_add_meshid_ie(sdata, skb) ||
266 mesh_add_meshconf_ie(sdata, skb))
267 goto free;
268 } else { /* WLAN_SP_MESH_PEERING_CLOSE */
269 info->flags |= IEEE80211_TX_CTL_NO_ACK;
270 if (mesh_add_meshid_ie(sdata, skb))
271 goto free;
272 }
273
274 /* Add Mesh Peering Management element */
275 switch (action) {
276 case WLAN_SP_MESH_PEERING_OPEN:
277 break;
278 case WLAN_SP_MESH_PEERING_CONFIRM:
279 ie_len += 2;
280 include_plid = true;
281 break;
282 case WLAN_SP_MESH_PEERING_CLOSE:
283 if (plid) {
284 ie_len += 2;
285 include_plid = true;
286 }
287 ie_len += 2; /* reason code */
288 break;
289 default:
290 err = -EINVAL;
291 goto free;
292 }
293
294 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
295 goto free;
296
297 pos = skb_put(skb, 2 + ie_len);
298 *pos++ = WLAN_EID_PEER_MGMT;
299 *pos++ = ie_len;
300 memcpy(pos, &peering_proto, 2);
301 pos += 2;
302 put_unaligned_le16(llid, pos);
303 pos += 2;
304 if (include_plid) {
305 put_unaligned_le16(plid, pos);
306 pos += 2;
307 }
308 if (action == WLAN_SP_MESH_PEERING_CLOSE) {
309 put_unaligned_le16(reason, pos);
310 pos += 2;
311 }
312
313 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
314 if (mesh_add_ht_cap_ie(sdata, skb) ||
315 mesh_add_ht_oper_ie(sdata, skb) ||
316 mesh_add_vht_cap_ie(sdata, skb) ||
317 mesh_add_vht_oper_ie(sdata, skb))
318 goto free;
319 }
320
321 if (mesh_add_vendor_ies(sdata, skb))
322 goto free;
323
324 ieee80211_tx_skb(sdata, skb);
325 return 0;
326 free:
327 kfree_skb(skb);
328 return err;
329 }
330
331 /**
332 * __mesh_plink_deactivate - deactivate mesh peer link
333 *
334 * @sta: mesh peer link to deactivate
335 *
336 * Mesh paths with this peer as next hop should be flushed
337 * by the caller outside of plink_lock.
338 *
339 * Returns beacon changed flag if the beacon content changed.
340 *
341 * Locking: the caller must hold sta->mesh->plink_lock
342 */
343 static u32 __mesh_plink_deactivate(struct sta_info *sta)
344 {
345 struct ieee80211_sub_if_data *sdata = sta->sdata;
346 u32 changed = 0;
347
348 lockdep_assert_held(&sta->mesh->plink_lock);
349
350 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
351 changed = mesh_plink_dec_estab_count(sdata);
352 sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
353
354 ieee80211_mps_sta_status_update(sta);
355 changed |= ieee80211_mps_set_sta_local_pm(sta,
356 NL80211_MESH_POWER_UNKNOWN);
357
358 return changed;
359 }
360
361 /**
362 * mesh_plink_deactivate - deactivate mesh peer link
363 *
364 * @sta: mesh peer link to deactivate
365 *
366 * All mesh paths with this peer as next hop will be flushed
367 */
368 u32 mesh_plink_deactivate(struct sta_info *sta)
369 {
370 struct ieee80211_sub_if_data *sdata = sta->sdata;
371 u32 changed;
372
373 spin_lock_bh(&sta->mesh->plink_lock);
374 changed = __mesh_plink_deactivate(sta);
375
376 if (!sdata->u.mesh.user_mpm) {
377 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED;
378 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE,
379 sta->sta.addr, sta->mesh->llid,
380 sta->mesh->plid, sta->mesh->reason);
381 }
382 spin_unlock_bh(&sta->mesh->plink_lock);
383 if (!sdata->u.mesh.user_mpm)
384 del_timer_sync(&sta->mesh->plink_timer);
385 mesh_path_flush_by_nexthop(sta);
386
387 /* make sure no readers can access nexthop sta from here on */
388 synchronize_net();
389
390 return changed;
391 }
392
393 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
394 struct sta_info *sta,
395 struct ieee802_11_elems *elems, bool insert)
396 {
397 struct ieee80211_local *local = sdata->local;
398 enum nl80211_band band = ieee80211_get_sdata_band(sdata);
399 struct ieee80211_supported_band *sband;
400 u32 rates, basic_rates = 0, changed = 0;
401 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth;
402
403 sband = local->hw.wiphy->bands[band];
404 rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates);
405
406 spin_lock_bh(&sta->mesh->plink_lock);
407 sta->rx_stats.last_rx = jiffies;
408
409 /* rates and capabilities don't change during peering */
410 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB &&
411 sta->mesh->processed_beacon)
412 goto out;
413 sta->mesh->processed_beacon = true;
414
415 if (sta->sta.supp_rates[band] != rates)
416 changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
417 sta->sta.supp_rates[band] = rates;
418
419 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
420 elems->ht_cap_elem, sta))
421 changed |= IEEE80211_RC_BW_CHANGED;
422
423 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
424 elems->vht_cap_elem, sta);
425
426 if (bw != sta->sta.bandwidth)
427 changed |= IEEE80211_RC_BW_CHANGED;
428
429 /* HT peer is operating 20MHz-only */
430 if (elems->ht_operation &&
431 !(elems->ht_operation->ht_param &
432 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
433 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20)
434 changed |= IEEE80211_RC_BW_CHANGED;
435 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20;
436 }
437
438 if (insert)
439 rate_control_rate_init(sta);
440 else
441 rate_control_rate_update(local, sband, sta, changed);
442 out:
443 spin_unlock_bh(&sta->mesh->plink_lock);
444 }
445
446 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata)
447 {
448 struct sta_info *sta;
449 unsigned long *aid_map;
450 int aid;
451
452 aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1),
453 sizeof(*aid_map), GFP_KERNEL);
454 if (!aid_map)
455 return -ENOMEM;
456
457 /* reserve aid 0 for mcast indication */
458 __set_bit(0, aid_map);
459
460 rcu_read_lock();
461 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list)
462 __set_bit(sta->sta.aid, aid_map);
463 rcu_read_unlock();
464
465 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1);
466 kfree(aid_map);
467
468 if (aid > IEEE80211_MAX_AID)
469 return -ENOBUFS;
470
471 return aid;
472 }
473
474 static struct sta_info *
475 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
476 {
477 struct sta_info *sta;
478 int aid;
479
480 if (sdata->local->num_sta >= MESH_MAX_PLINKS)
481 return NULL;
482
483 aid = mesh_allocate_aid(sdata);
484 if (aid < 0)
485 return NULL;
486
487 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
488 if (!sta)
489 return NULL;
490
491 sta->mesh->plink_state = NL80211_PLINK_LISTEN;
492 sta->sta.wme = true;
493 sta->sta.aid = aid;
494
495 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
496 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
497 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
498
499 return sta;
500 }
501
502 static struct sta_info *
503 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
504 struct ieee802_11_elems *elems)
505 {
506 struct sta_info *sta = NULL;
507
508 /* Userspace handles station allocation */
509 if (sdata->u.mesh.user_mpm ||
510 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) {
511 if (mesh_peer_accepts_plinks(elems) &&
512 mesh_plink_availables(sdata))
513 cfg80211_notify_new_peer_candidate(sdata->dev, addr,
514 elems->ie_start,
515 elems->total_len,
516 GFP_KERNEL);
517 } else
518 sta = __mesh_sta_info_alloc(sdata, addr);
519
520 return sta;
521 }
522
523 /*
524 * mesh_sta_info_get - return mesh sta info entry for @addr.
525 *
526 * @sdata: local meshif
527 * @addr: peer's address
528 * @elems: IEs from beacon or mesh peering frame.
529 *
530 * Return existing or newly allocated sta_info under RCU read lock.
531 * (re)initialize with given IEs.
532 */
533 static struct sta_info *
534 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
535 u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU)
536 {
537 struct sta_info *sta = NULL;
538
539 rcu_read_lock();
540 sta = sta_info_get(sdata, addr);
541 if (sta) {
542 mesh_sta_info_init(sdata, sta, elems, false);
543 } else {
544 rcu_read_unlock();
545 /* can't run atomic */
546 sta = mesh_sta_info_alloc(sdata, addr, elems);
547 if (!sta) {
548 rcu_read_lock();
549 return NULL;
550 }
551
552 mesh_sta_info_init(sdata, sta, elems, true);
553
554 if (sta_info_insert_rcu(sta))
555 return NULL;
556 }
557
558 return sta;
559 }
560
561 /*
562 * mesh_neighbour_update - update or initialize new mesh neighbor.
563 *
564 * @sdata: local meshif
565 * @addr: peer's address
566 * @elems: IEs from beacon or mesh peering frame
567 *
568 * Initiates peering if appropriate.
569 */
570 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
571 u8 *hw_addr,
572 struct ieee802_11_elems *elems)
573 {
574 struct sta_info *sta;
575 u32 changed = 0;
576
577 sta = mesh_sta_info_get(sdata, hw_addr, elems);
578 if (!sta)
579 goto out;
580
581 if (mesh_peer_accepts_plinks(elems) &&
582 sta->mesh->plink_state == NL80211_PLINK_LISTEN &&
583 sdata->u.mesh.accepting_plinks &&
584 sdata->u.mesh.mshcfg.auto_open_plinks &&
585 rssi_threshold_check(sdata, sta))
586 changed = mesh_plink_open(sta);
587
588 ieee80211_mps_frame_release(sta, elems);
589 out:
590 rcu_read_unlock();
591 ieee80211_mbss_info_change_notify(sdata, changed);
592 }
593
594 static void mesh_plink_timer(unsigned long data)
595 {
596 struct sta_info *sta;
597 u16 reason = 0;
598 struct ieee80211_sub_if_data *sdata;
599 struct mesh_config *mshcfg;
600 enum ieee80211_self_protected_actioncode action = 0;
601
602 /*
603 * This STA is valid because sta_info_destroy() will
604 * del_timer_sync() this timer after having made sure
605 * it cannot be readded (by deleting the plink.)
606 */
607 sta = (struct sta_info *) data;
608
609 if (sta->sdata->local->quiescing)
610 return;
611
612 spin_lock_bh(&sta->mesh->plink_lock);
613
614 /* If a timer fires just before a state transition on another CPU,
615 * we may have already extended the timeout and changed state by the
616 * time we've acquired the lock and arrived here. In that case,
617 * skip this timer and wait for the new one.
618 */
619 if (time_before(jiffies, sta->mesh->plink_timer.expires)) {
620 mpl_dbg(sta->sdata,
621 "Ignoring timer for %pM in state %s (timer adjusted)",
622 sta->sta.addr, mplstates[sta->mesh->plink_state]);
623 spin_unlock_bh(&sta->mesh->plink_lock);
624 return;
625 }
626
627 /* del_timer() and handler may race when entering these states */
628 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN ||
629 sta->mesh->plink_state == NL80211_PLINK_ESTAB) {
630 mpl_dbg(sta->sdata,
631 "Ignoring timer for %pM in state %s (timer deleted)",
632 sta->sta.addr, mplstates[sta->mesh->plink_state]);
633 spin_unlock_bh(&sta->mesh->plink_lock);
634 return;
635 }
636
637 mpl_dbg(sta->sdata,
638 "Mesh plink timer for %pM fired on state %s\n",
639 sta->sta.addr, mplstates[sta->mesh->plink_state]);
640 sdata = sta->sdata;
641 mshcfg = &sdata->u.mesh.mshcfg;
642
643 switch (sta->mesh->plink_state) {
644 case NL80211_PLINK_OPN_RCVD:
645 case NL80211_PLINK_OPN_SNT:
646 /* retry timer */
647 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) {
648 u32 rand;
649 mpl_dbg(sta->sdata,
650 "Mesh plink for %pM (retry, timeout): %d %d\n",
651 sta->sta.addr, sta->mesh->plink_retries,
652 sta->mesh->plink_timeout);
653 get_random_bytes(&rand, sizeof(u32));
654 sta->mesh->plink_timeout = sta->mesh->plink_timeout +
655 rand % sta->mesh->plink_timeout;
656 ++sta->mesh->plink_retries;
657 mod_plink_timer(sta, sta->mesh->plink_timeout);
658 action = WLAN_SP_MESH_PEERING_OPEN;
659 break;
660 }
661 reason = WLAN_REASON_MESH_MAX_RETRIES;
662 /* fall through on else */
663 case NL80211_PLINK_CNF_RCVD:
664 /* confirm timer */
665 if (!reason)
666 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT;
667 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
668 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
669 action = WLAN_SP_MESH_PEERING_CLOSE;
670 break;
671 case NL80211_PLINK_HOLDING:
672 /* holding timer */
673 del_timer(&sta->mesh->plink_timer);
674 mesh_plink_fsm_restart(sta);
675 break;
676 default:
677 break;
678 }
679 spin_unlock_bh(&sta->mesh->plink_lock);
680 if (action)
681 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
682 sta->mesh->llid, sta->mesh->plid, reason);
683 }
684
685 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout)
686 {
687 sta->mesh->plink_timer.expires = jiffies + msecs_to_jiffies(timeout);
688 sta->mesh->plink_timer.data = (unsigned long) sta;
689 sta->mesh->plink_timer.function = mesh_plink_timer;
690 sta->mesh->plink_timeout = timeout;
691 add_timer(&sta->mesh->plink_timer);
692 }
693
694 static bool llid_in_use(struct ieee80211_sub_if_data *sdata,
695 u16 llid)
696 {
697 struct ieee80211_local *local = sdata->local;
698 bool in_use = false;
699 struct sta_info *sta;
700
701 rcu_read_lock();
702 list_for_each_entry_rcu(sta, &local->sta_list, list) {
703 if (sdata != sta->sdata)
704 continue;
705
706 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) {
707 in_use = true;
708 break;
709 }
710 }
711 rcu_read_unlock();
712
713 return in_use;
714 }
715
716 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata)
717 {
718 u16 llid;
719
720 do {
721 get_random_bytes(&llid, sizeof(llid));
722 } while (llid_in_use(sdata, llid));
723
724 return llid;
725 }
726
727 u32 mesh_plink_open(struct sta_info *sta)
728 {
729 struct ieee80211_sub_if_data *sdata = sta->sdata;
730 u32 changed;
731
732 if (!test_sta_flag(sta, WLAN_STA_AUTH))
733 return 0;
734
735 spin_lock_bh(&sta->mesh->plink_lock);
736 sta->mesh->llid = mesh_get_new_llid(sdata);
737 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN &&
738 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) {
739 spin_unlock_bh(&sta->mesh->plink_lock);
740 return 0;
741 }
742 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT;
743 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
744 spin_unlock_bh(&sta->mesh->plink_lock);
745 mpl_dbg(sdata,
746 "Mesh plink: starting establishment with %pM\n",
747 sta->sta.addr);
748
749 /* set the non-peer mode to active during peering */
750 changed = ieee80211_mps_local_status_update(sdata);
751
752 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN,
753 sta->sta.addr, sta->mesh->llid, 0, 0);
754 return changed;
755 }
756
757 u32 mesh_plink_block(struct sta_info *sta)
758 {
759 u32 changed;
760
761 spin_lock_bh(&sta->mesh->plink_lock);
762 changed = __mesh_plink_deactivate(sta);
763 sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
764 spin_unlock_bh(&sta->mesh->plink_lock);
765 mesh_path_flush_by_nexthop(sta);
766
767 return changed;
768 }
769
770 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata,
771 struct sta_info *sta,
772 enum plink_event event)
773 {
774 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
775 u16 reason = (event == CLS_ACPT) ?
776 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG;
777
778 sta->mesh->reason = reason;
779 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
780 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
781 }
782
783 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata,
784 struct sta_info *sta)
785 {
786 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
787 u32 changed = 0;
788
789 del_timer(&sta->mesh->plink_timer);
790 sta->mesh->plink_state = NL80211_PLINK_ESTAB;
791 changed |= mesh_plink_inc_estab_count(sdata);
792 changed |= mesh_set_ht_prot_mode(sdata);
793 changed |= mesh_set_short_slot_time(sdata);
794 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr);
795 ieee80211_mps_sta_status_update(sta);
796 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode);
797 return changed;
798 }
799
800 /**
801 * mesh_plink_fsm - step @sta MPM based on @event
802 *
803 * @sdata: interface
804 * @sta: mesh neighbor
805 * @event: peering event
806 *
807 * Return: changed MBSS flags
808 */
809 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata,
810 struct sta_info *sta, enum plink_event event)
811 {
812 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
813 enum ieee80211_self_protected_actioncode action = 0;
814 u32 changed = 0;
815 bool flush = false;
816
817 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr,
818 mplstates[sta->mesh->plink_state], mplevents[event]);
819
820 spin_lock_bh(&sta->mesh->plink_lock);
821 switch (sta->mesh->plink_state) {
822 case NL80211_PLINK_LISTEN:
823 switch (event) {
824 case CLS_ACPT:
825 mesh_plink_fsm_restart(sta);
826 break;
827 case OPN_ACPT:
828 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
829 sta->mesh->llid = mesh_get_new_llid(sdata);
830 mesh_plink_timer_set(sta,
831 mshcfg->dot11MeshRetryTimeout);
832
833 /* set the non-peer mode to active during peering */
834 changed |= ieee80211_mps_local_status_update(sdata);
835 action = WLAN_SP_MESH_PEERING_OPEN;
836 break;
837 default:
838 break;
839 }
840 break;
841 case NL80211_PLINK_OPN_SNT:
842 switch (event) {
843 case OPN_RJCT:
844 case CNF_RJCT:
845 case CLS_ACPT:
846 mesh_plink_close(sdata, sta, event);
847 action = WLAN_SP_MESH_PEERING_CLOSE;
848 break;
849 case OPN_ACPT:
850 /* retry timer is left untouched */
851 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
852 action = WLAN_SP_MESH_PEERING_CONFIRM;
853 break;
854 case CNF_ACPT:
855 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD;
856 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout);
857 break;
858 default:
859 break;
860 }
861 break;
862 case NL80211_PLINK_OPN_RCVD:
863 switch (event) {
864 case OPN_RJCT:
865 case CNF_RJCT:
866 case CLS_ACPT:
867 mesh_plink_close(sdata, sta, event);
868 action = WLAN_SP_MESH_PEERING_CLOSE;
869 break;
870 case OPN_ACPT:
871 action = WLAN_SP_MESH_PEERING_CONFIRM;
872 break;
873 case CNF_ACPT:
874 changed |= mesh_plink_establish(sdata, sta);
875 break;
876 default:
877 break;
878 }
879 break;
880 case NL80211_PLINK_CNF_RCVD:
881 switch (event) {
882 case OPN_RJCT:
883 case CNF_RJCT:
884 case CLS_ACPT:
885 mesh_plink_close(sdata, sta, event);
886 action = WLAN_SP_MESH_PEERING_CLOSE;
887 break;
888 case OPN_ACPT:
889 changed |= mesh_plink_establish(sdata, sta);
890 action = WLAN_SP_MESH_PEERING_CONFIRM;
891 break;
892 default:
893 break;
894 }
895 break;
896 case NL80211_PLINK_ESTAB:
897 switch (event) {
898 case CLS_ACPT:
899 changed |= __mesh_plink_deactivate(sta);
900 changed |= mesh_set_ht_prot_mode(sdata);
901 changed |= mesh_set_short_slot_time(sdata);
902 mesh_plink_close(sdata, sta, event);
903 action = WLAN_SP_MESH_PEERING_CLOSE;
904 flush = true;
905 break;
906 case OPN_ACPT:
907 action = WLAN_SP_MESH_PEERING_CONFIRM;
908 break;
909 default:
910 break;
911 }
912 break;
913 case NL80211_PLINK_HOLDING:
914 switch (event) {
915 case CLS_ACPT:
916 del_timer(&sta->mesh->plink_timer);
917 mesh_plink_fsm_restart(sta);
918 break;
919 case OPN_ACPT:
920 case CNF_ACPT:
921 case OPN_RJCT:
922 case CNF_RJCT:
923 action = WLAN_SP_MESH_PEERING_CLOSE;
924 break;
925 default:
926 break;
927 }
928 break;
929 default:
930 /* should not get here, PLINK_BLOCKED is dealt with at the
931 * beginning of the function
932 */
933 break;
934 }
935 spin_unlock_bh(&sta->mesh->plink_lock);
936 if (flush)
937 mesh_path_flush_by_nexthop(sta);
938 if (action) {
939 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
940 sta->mesh->llid, sta->mesh->plid,
941 sta->mesh->reason);
942
943 /* also send confirm in open case */
944 if (action == WLAN_SP_MESH_PEERING_OPEN) {
945 mesh_plink_frame_tx(sdata, sta,
946 WLAN_SP_MESH_PEERING_CONFIRM,
947 sta->sta.addr, sta->mesh->llid,
948 sta->mesh->plid, 0);
949 }
950 }
951
952 return changed;
953 }
954
955 /*
956 * mesh_plink_get_event - get correct MPM event
957 *
958 * @sdata: interface
959 * @sta: peer, leave NULL if processing a frame from a new suitable peer
960 * @elems: peering management IEs
961 * @ftype: frame type
962 * @llid: peer's peer link ID
963 * @plid: peer's local link ID
964 *
965 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as
966 * an error.
967 */
968 static enum plink_event
969 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata,
970 struct sta_info *sta,
971 struct ieee802_11_elems *elems,
972 enum ieee80211_self_protected_actioncode ftype,
973 u16 llid, u16 plid)
974 {
975 enum plink_event event = PLINK_UNDEFINED;
976 u8 ie_len = elems->peering_len;
977 bool matches_local;
978
979 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE ||
980 mesh_matches_local(sdata, elems));
981
982 /* deny open request from non-matching peer */
983 if (!matches_local && !sta) {
984 event = OPN_RJCT;
985 goto out;
986 }
987
988 if (!sta) {
989 if (ftype != WLAN_SP_MESH_PEERING_OPEN) {
990 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
991 goto out;
992 }
993 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
994 if (!mesh_plink_free_count(sdata)) {
995 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
996 goto out;
997 }
998
999 /* new matching peer */
1000 event = OPN_ACPT;
1001 goto out;
1002 } else {
1003 if (!test_sta_flag(sta, WLAN_STA_AUTH)) {
1004 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
1005 goto out;
1006 }
1007 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED)
1008 goto out;
1009 }
1010
1011 switch (ftype) {
1012 case WLAN_SP_MESH_PEERING_OPEN:
1013 if (!matches_local)
1014 event = OPN_RJCT;
1015 if (!mesh_plink_free_count(sdata) ||
1016 (sta->mesh->plid && sta->mesh->plid != plid))
1017 event = OPN_IGNR;
1018 else
1019 event = OPN_ACPT;
1020 break;
1021 case WLAN_SP_MESH_PEERING_CONFIRM:
1022 if (!matches_local)
1023 event = CNF_RJCT;
1024 if (!mesh_plink_free_count(sdata) ||
1025 sta->mesh->llid != llid ||
1026 (sta->mesh->plid && sta->mesh->plid != plid))
1027 event = CNF_IGNR;
1028 else
1029 event = CNF_ACPT;
1030 break;
1031 case WLAN_SP_MESH_PEERING_CLOSE:
1032 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
1033 /* Do not check for llid or plid. This does not
1034 * follow the standard but since multiple plinks
1035 * per sta are not supported, it is necessary in
1036 * order to avoid a livelock when MP A sees an
1037 * establish peer link to MP B but MP B does not
1038 * see it. This can be caused by a timeout in
1039 * B's peer link establishment or B beign
1040 * restarted.
1041 */
1042 event = CLS_ACPT;
1043 else if (sta->mesh->plid != plid)
1044 event = CLS_IGNR;
1045 else if (ie_len == 8 && sta->mesh->llid != llid)
1046 event = CLS_IGNR;
1047 else
1048 event = CLS_ACPT;
1049 break;
1050 default:
1051 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
1052 break;
1053 }
1054
1055 out:
1056 return event;
1057 }
1058
1059 static void
1060 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
1061 struct ieee80211_mgmt *mgmt,
1062 struct ieee802_11_elems *elems)
1063 {
1064
1065 struct sta_info *sta;
1066 enum plink_event event;
1067 enum ieee80211_self_protected_actioncode ftype;
1068 u32 changed = 0;
1069 u8 ie_len = elems->peering_len;
1070 u16 plid, llid = 0;
1071
1072 if (!elems->peering) {
1073 mpl_dbg(sdata,
1074 "Mesh plink: missing necessary peer link ie\n");
1075 return;
1076 }
1077
1078 if (elems->rsn_len &&
1079 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
1080 mpl_dbg(sdata,
1081 "Mesh plink: can't establish link with secure peer\n");
1082 return;
1083 }
1084
1085 ftype = mgmt->u.action.u.self_prot.action_code;
1086 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
1087 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
1088 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
1089 && ie_len != 8)) {
1090 mpl_dbg(sdata,
1091 "Mesh plink: incorrect plink ie length %d %d\n",
1092 ftype, ie_len);
1093 return;
1094 }
1095
1096 if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
1097 (!elems->mesh_id || !elems->mesh_config)) {
1098 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
1099 return;
1100 }
1101 /* Note the lines below are correct, the llid in the frame is the plid
1102 * from the point of view of this host.
1103 */
1104 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering));
1105 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
1106 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
1107 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering));
1108
1109 /* WARNING: Only for sta pointer, is dropped & re-acquired */
1110 rcu_read_lock();
1111
1112 sta = sta_info_get(sdata, mgmt->sa);
1113
1114 if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
1115 !rssi_threshold_check(sdata, sta)) {
1116 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
1117 mgmt->sa);
1118 goto unlock_rcu;
1119 }
1120
1121 /* Now we will figure out the appropriate event... */
1122 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid);
1123
1124 if (event == OPN_ACPT) {
1125 rcu_read_unlock();
1126 /* allocate sta entry if necessary and update info */
1127 sta = mesh_sta_info_get(sdata, mgmt->sa, elems);
1128 if (!sta) {
1129 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
1130 goto unlock_rcu;
1131 }
1132 sta->mesh->plid = plid;
1133 } else if (!sta && event == OPN_RJCT) {
1134 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE,
1135 mgmt->sa, 0, plid,
1136 WLAN_REASON_MESH_CONFIG);
1137 goto unlock_rcu;
1138 } else if (!sta || event == PLINK_UNDEFINED) {
1139 /* something went wrong */
1140 goto unlock_rcu;
1141 }
1142
1143 if (event == CNF_ACPT) {
1144 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */
1145 if (!sta->mesh->plid)
1146 sta->mesh->plid = plid;
1147
1148 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt));
1149 }
1150
1151 changed |= mesh_plink_fsm(sdata, sta, event);
1152
1153 unlock_rcu:
1154 rcu_read_unlock();
1155
1156 if (changed)
1157 ieee80211_mbss_info_change_notify(sdata, changed);
1158 }
1159
1160 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
1161 struct ieee80211_mgmt *mgmt, size_t len,
1162 struct ieee80211_rx_status *rx_status)
1163 {
1164 struct ieee802_11_elems elems;
1165 size_t baselen;
1166 u8 *baseaddr;
1167
1168 /* need action_code, aux */
1169 if (len < IEEE80211_MIN_ACTION_SIZE + 3)
1170 return;
1171
1172 if (sdata->u.mesh.user_mpm)
1173 /* userspace must register for these */
1174 return;
1175
1176 if (is_multicast_ether_addr(mgmt->da)) {
1177 mpl_dbg(sdata,
1178 "Mesh plink: ignore frame from multicast address\n");
1179 return;
1180 }
1181
1182 baseaddr = mgmt->u.action.u.self_prot.variable;
1183 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
1184 if (mgmt->u.action.u.self_prot.action_code ==
1185 WLAN_SP_MESH_PEERING_CONFIRM) {
1186 baseaddr += 4;
1187 baselen += 4;
1188
1189 if (baselen > len)
1190 return;
1191 }
1192 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems);
1193 mesh_process_plink_frame(sdata, mgmt, &elems);
1194 }
Linux with added FPC-III support