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Linux 4.13.16
[linux/fpc-iii.git] / net / mac80211 / mesh_plink.c
blobf69c6c38ca4399769064712aaf81ce264a826ec7
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 struct ieee80211_supported_band *sband;
99 struct sta_info *sta;
100 u32 erp_rates = 0, changed = 0;
101 int i;
102 bool short_slot = false;
103
104 sband = ieee80211_get_sband(sdata);
105 if (!sband)
106 return changed;
107
108 if (sband->band == NL80211_BAND_5GHZ) {
109 /* (IEEE 802.11-2012 19.4.5) */
110 short_slot = true;
111 goto out;
112 } else if (sband->band != NL80211_BAND_2GHZ) {
113 goto out;
114 }
115
116 for (i = 0; i < sband->n_bitrates; i++)
117 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)
118 erp_rates |= BIT(i);
119
120 if (!erp_rates)
121 goto out;
122
123 rcu_read_lock();
124 list_for_each_entry_rcu(sta, &local->sta_list, list) {
125 if (sdata != sta->sdata ||
126 sta->mesh->plink_state != NL80211_PLINK_ESTAB)
127 continue;
128
129 short_slot = false;
130 if (erp_rates & sta->sta.supp_rates[sband->band])
131 short_slot = true;
132 else
133 break;
134 }
135 rcu_read_unlock();
136
137 out:
138 if (sdata->vif.bss_conf.use_short_slot != short_slot) {
139 sdata->vif.bss_conf.use_short_slot = short_slot;
140 changed = BSS_CHANGED_ERP_SLOT;
141 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n",
142 sdata->vif.addr, short_slot);
143 }
144 return changed;
145 }
146
147 /**
148 * mesh_set_ht_prot_mode - set correct HT protection mode
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 atleast one
155 * HT20 peer is present. Otherwise no-protection mode is selected.
156 */
157 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
158 {
159 struct ieee80211_local *local = sdata->local;
160 struct sta_info *sta;
161 u16 ht_opmode;
162 bool non_ht_sta = false, ht20_sta = false;
163
164 switch (sdata->vif.bss_conf.chandef.width) {
165 case NL80211_CHAN_WIDTH_20_NOHT:
166 case NL80211_CHAN_WIDTH_5:
167 case NL80211_CHAN_WIDTH_10:
168 return 0;
169 default:
170 break;
171 }
172
173 rcu_read_lock();
174 list_for_each_entry_rcu(sta, &local->sta_list, list) {
175 if (sdata != sta->sdata ||
176 sta->mesh->plink_state != NL80211_PLINK_ESTAB)
177 continue;
178
179 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20)
180 continue;
181
182 if (!sta->sta.ht_cap.ht_supported) {
183 mpl_dbg(sdata, "nonHT sta (%pM) is present\n",
184 sta->sta.addr);
185 non_ht_sta = true;
186 break;
187 }
188
189 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr);
190 ht20_sta = true;
191 }
192 rcu_read_unlock();
193
194 if (non_ht_sta)
195 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
196 else if (ht20_sta &&
197 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20)
198 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
199 else
200 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
201
202 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode)
203 return 0;
204
205 sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
206 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
207 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode);
208 return BSS_CHANGED_HT;
209 }
210
211 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
212 struct sta_info *sta,
213 enum ieee80211_self_protected_actioncode action,
214 u8 *da, u16 llid, u16 plid, u16 reason)
215 {
216 struct ieee80211_local *local = sdata->local;
217 struct sk_buff *skb;
218 struct ieee80211_tx_info *info;
219 struct ieee80211_mgmt *mgmt;
220 bool include_plid = false;
221 u16 peering_proto = 0;
222 u8 *pos, ie_len = 4;
223 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) +
224 sizeof(mgmt->u.action.u.self_prot);
225 int err = -ENOMEM;
226
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 2 + 8 + /* peering IE */
240 sdata->u.mesh.ie_len);
241 if (!skb)
242 return err;
243 info = IEEE80211_SKB_CB(skb);
244 skb_reserve(skb, local->tx_headroom);
245 mgmt = skb_put_zero(skb, hdr_len);
246 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
247 IEEE80211_STYPE_ACTION);
248 memcpy(mgmt->da, da, ETH_ALEN);
249 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
250 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
251 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
252 mgmt->u.action.u.self_prot.action_code = action;
253
254 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
255 struct ieee80211_supported_band *sband;
256 enum nl80211_band band;
257
258 sband = ieee80211_get_sband(sdata);
259 if (!sband) {
260 err = -EINVAL;
261 goto free;
262 }
263 band = sband->band;
264
265 /* capability info */
266 pos = skb_put_zero(skb, 2);
267 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
268 /* AID */
269 pos = skb_put(skb, 2);
270 put_unaligned_le16(sta->sta.aid, pos);
271 }
272 if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
273 ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
274 mesh_add_rsn_ie(sdata, skb) ||
275 mesh_add_meshid_ie(sdata, skb) ||
276 mesh_add_meshconf_ie(sdata, skb))
277 goto free;
278 } else { /* WLAN_SP_MESH_PEERING_CLOSE */
279 info->flags |= IEEE80211_TX_CTL_NO_ACK;
280 if (mesh_add_meshid_ie(sdata, skb))
281 goto free;
282 }
283
284 /* Add Mesh Peering Management element */
285 switch (action) {
286 case WLAN_SP_MESH_PEERING_OPEN:
287 break;
288 case WLAN_SP_MESH_PEERING_CONFIRM:
289 ie_len += 2;
290 include_plid = true;
291 break;
292 case WLAN_SP_MESH_PEERING_CLOSE:
293 if (plid) {
294 ie_len += 2;
295 include_plid = true;
296 }
297 ie_len += 2; /* reason code */
298 break;
299 default:
300 err = -EINVAL;
301 goto free;
302 }
303
304 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
305 goto free;
306
307 pos = skb_put(skb, 2 + ie_len);
308 *pos++ = WLAN_EID_PEER_MGMT;
309 *pos++ = ie_len;
310 memcpy(pos, &peering_proto, 2);
311 pos += 2;
312 put_unaligned_le16(llid, pos);
313 pos += 2;
314 if (include_plid) {
315 put_unaligned_le16(plid, pos);
316 pos += 2;
317 }
318 if (action == WLAN_SP_MESH_PEERING_CLOSE) {
319 put_unaligned_le16(reason, pos);
320 pos += 2;
321 }
322
323 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
324 if (mesh_add_ht_cap_ie(sdata, skb) ||
325 mesh_add_ht_oper_ie(sdata, skb) ||
326 mesh_add_vht_cap_ie(sdata, skb) ||
327 mesh_add_vht_oper_ie(sdata, skb))
328 goto free;
329 }
330
331 if (mesh_add_vendor_ies(sdata, skb))
332 goto free;
333
334 ieee80211_tx_skb(sdata, skb);
335 return 0;
336 free:
337 kfree_skb(skb);
338 return err;
339 }
340
341 /**
342 * __mesh_plink_deactivate - deactivate mesh peer link
343 *
344 * @sta: mesh peer link to deactivate
345 *
346 * Mesh paths with this peer as next hop should be flushed
347 * by the caller outside of plink_lock.
348 *
349 * Returns beacon changed flag if the beacon content changed.
350 *
351 * Locking: the caller must hold sta->mesh->plink_lock
352 */
353 static u32 __mesh_plink_deactivate(struct sta_info *sta)
354 {
355 struct ieee80211_sub_if_data *sdata = sta->sdata;
356 u32 changed = 0;
357
358 lockdep_assert_held(&sta->mesh->plink_lock);
359
360 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
361 changed = mesh_plink_dec_estab_count(sdata);
362 sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
363
364 ieee80211_mps_sta_status_update(sta);
365 changed |= ieee80211_mps_set_sta_local_pm(sta,
366 NL80211_MESH_POWER_UNKNOWN);
367
368 return changed;
369 }
370
371 /**
372 * mesh_plink_deactivate - deactivate mesh peer link
373 *
374 * @sta: mesh peer link to deactivate
375 *
376 * All mesh paths with this peer as next hop will be flushed
377 */
378 u32 mesh_plink_deactivate(struct sta_info *sta)
379 {
380 struct ieee80211_sub_if_data *sdata = sta->sdata;
381 u32 changed;
382
383 spin_lock_bh(&sta->mesh->plink_lock);
384 changed = __mesh_plink_deactivate(sta);
385
386 if (!sdata->u.mesh.user_mpm) {
387 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED;
388 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE,
389 sta->sta.addr, sta->mesh->llid,
390 sta->mesh->plid, sta->mesh->reason);
391 }
392 spin_unlock_bh(&sta->mesh->plink_lock);
393 if (!sdata->u.mesh.user_mpm)
394 del_timer_sync(&sta->mesh->plink_timer);
395 mesh_path_flush_by_nexthop(sta);
396
397 /* make sure no readers can access nexthop sta from here on */
398 synchronize_net();
399
400 return changed;
401 }
402
403 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
404 struct sta_info *sta,
405 struct ieee802_11_elems *elems, bool insert)
406 {
407 struct ieee80211_local *local = sdata->local;
408 struct ieee80211_supported_band *sband;
409 u32 rates, basic_rates = 0, changed = 0;
410 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth;
411
412 sband = ieee80211_get_sband(sdata);
413 if (!sband)
414 return;
415
416 rates = ieee80211_sta_get_rates(sdata, elems, sband->band,
417 &basic_rates);
418
419 spin_lock_bh(&sta->mesh->plink_lock);
420 sta->rx_stats.last_rx = jiffies;
421
422 /* rates and capabilities don't change during peering */
423 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB &&
424 sta->mesh->processed_beacon)
425 goto out;
426 sta->mesh->processed_beacon = true;
427
428 if (sta->sta.supp_rates[sband->band] != rates)
429 changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
430 sta->sta.supp_rates[sband->band] = rates;
431
432 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
433 elems->ht_cap_elem, sta))
434 changed |= IEEE80211_RC_BW_CHANGED;
435
436 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
437 elems->vht_cap_elem, sta);
438
439 if (bw != sta->sta.bandwidth)
440 changed |= IEEE80211_RC_BW_CHANGED;
441
442 /* HT peer is operating 20MHz-only */
443 if (elems->ht_operation &&
444 !(elems->ht_operation->ht_param &
445 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
446 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20)
447 changed |= IEEE80211_RC_BW_CHANGED;
448 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20;
449 }
450
451 if (insert)
452 rate_control_rate_init(sta);
453 else
454 rate_control_rate_update(local, sband, sta, changed);
455 out:
456 spin_unlock_bh(&sta->mesh->plink_lock);
457 }
458
459 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata)
460 {
461 struct sta_info *sta;
462 unsigned long *aid_map;
463 int aid;
464
465 aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1),
466 sizeof(*aid_map), GFP_KERNEL);
467 if (!aid_map)
468 return -ENOMEM;
469
470 /* reserve aid 0 for mcast indication */
471 __set_bit(0, aid_map);
472
473 rcu_read_lock();
474 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list)
475 __set_bit(sta->sta.aid, aid_map);
476 rcu_read_unlock();
477
478 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1);
479 kfree(aid_map);
480
481 if (aid > IEEE80211_MAX_AID)
482 return -ENOBUFS;
483
484 return aid;
485 }
486
487 static struct sta_info *
488 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
489 {
490 struct sta_info *sta;
491 int aid;
492
493 if (sdata->local->num_sta >= MESH_MAX_PLINKS)
494 return NULL;
495
496 aid = mesh_allocate_aid(sdata);
497 if (aid < 0)
498 return NULL;
499
500 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
501 if (!sta)
502 return NULL;
503
504 sta->mesh->plink_state = NL80211_PLINK_LISTEN;
505 sta->sta.wme = true;
506 sta->sta.aid = aid;
507
508 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
509 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
510 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
511
512 return sta;
513 }
514
515 static struct sta_info *
516 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
517 struct ieee802_11_elems *elems)
518 {
519 struct sta_info *sta = NULL;
520
521 /* Userspace handles station allocation */
522 if (sdata->u.mesh.user_mpm ||
523 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) {
524 if (mesh_peer_accepts_plinks(elems) &&
525 mesh_plink_availables(sdata))
526 cfg80211_notify_new_peer_candidate(sdata->dev, addr,
527 elems->ie_start,
528 elems->total_len,
529 GFP_KERNEL);
530 } else
531 sta = __mesh_sta_info_alloc(sdata, addr);
532
533 return sta;
534 }
535
536 /*
537 * mesh_sta_info_get - return mesh sta info entry for @addr.
538 *
539 * @sdata: local meshif
540 * @addr: peer's address
541 * @elems: IEs from beacon or mesh peering frame.
542 *
543 * Return existing or newly allocated sta_info under RCU read lock.
544 * (re)initialize with given IEs.
545 */
546 static struct sta_info *
547 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
548 u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU)
549 {
550 struct sta_info *sta = NULL;
551
552 rcu_read_lock();
553 sta = sta_info_get(sdata, addr);
554 if (sta) {
555 mesh_sta_info_init(sdata, sta, elems, false);
556 } else {
557 rcu_read_unlock();
558 /* can't run atomic */
559 sta = mesh_sta_info_alloc(sdata, addr, elems);
560 if (!sta) {
561 rcu_read_lock();
562 return NULL;
563 }
564
565 mesh_sta_info_init(sdata, sta, elems, true);
566
567 if (sta_info_insert_rcu(sta))
568 return NULL;
569 }
570
571 return sta;
572 }
573
574 /*
575 * mesh_neighbour_update - update or initialize new mesh neighbor.
576 *
577 * @sdata: local meshif
578 * @addr: peer's address
579 * @elems: IEs from beacon or mesh peering frame
580 *
581 * Initiates peering if appropriate.
582 */
583 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
584 u8 *hw_addr,
585 struct ieee802_11_elems *elems)
586 {
587 struct sta_info *sta;
588 u32 changed = 0;
589
590 sta = mesh_sta_info_get(sdata, hw_addr, elems);
591 if (!sta)
592 goto out;
593
594 if (mesh_peer_accepts_plinks(elems) &&
595 sta->mesh->plink_state == NL80211_PLINK_LISTEN &&
596 sdata->u.mesh.accepting_plinks &&
597 sdata->u.mesh.mshcfg.auto_open_plinks &&
598 rssi_threshold_check(sdata, sta))
599 changed = mesh_plink_open(sta);
600
601 ieee80211_mps_frame_release(sta, elems);
602 out:
603 rcu_read_unlock();
604 ieee80211_mbss_info_change_notify(sdata, changed);
605 }
606
607 static void mesh_plink_timer(unsigned long data)
608 {
609 struct sta_info *sta;
610 u16 reason = 0;
611 struct ieee80211_sub_if_data *sdata;
612 struct mesh_config *mshcfg;
613 enum ieee80211_self_protected_actioncode action = 0;
614
615 /*
616 * This STA is valid because sta_info_destroy() will
617 * del_timer_sync() this timer after having made sure
618 * it cannot be readded (by deleting the plink.)
619 */
620 sta = (struct sta_info *) data;
621
622 if (sta->sdata->local->quiescing)
623 return;
624
625 spin_lock_bh(&sta->mesh->plink_lock);
626
627 /* If a timer fires just before a state transition on another CPU,
628 * we may have already extended the timeout and changed state by the
629 * time we've acquired the lock and arrived here. In that case,
630 * skip this timer and wait for the new one.
631 */
632 if (time_before(jiffies, sta->mesh->plink_timer.expires)) {
633 mpl_dbg(sta->sdata,
634 "Ignoring timer for %pM in state %s (timer adjusted)",
635 sta->sta.addr, mplstates[sta->mesh->plink_state]);
636 spin_unlock_bh(&sta->mesh->plink_lock);
637 return;
638 }
639
640 /* del_timer() and handler may race when entering these states */
641 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN ||
642 sta->mesh->plink_state == NL80211_PLINK_ESTAB) {
643 mpl_dbg(sta->sdata,
644 "Ignoring timer for %pM in state %s (timer deleted)",
645 sta->sta.addr, mplstates[sta->mesh->plink_state]);
646 spin_unlock_bh(&sta->mesh->plink_lock);
647 return;
648 }
649
650 mpl_dbg(sta->sdata,
651 "Mesh plink timer for %pM fired on state %s\n",
652 sta->sta.addr, mplstates[sta->mesh->plink_state]);
653 sdata = sta->sdata;
654 mshcfg = &sdata->u.mesh.mshcfg;
655
656 switch (sta->mesh->plink_state) {
657 case NL80211_PLINK_OPN_RCVD:
658 case NL80211_PLINK_OPN_SNT:
659 /* retry timer */
660 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) {
661 u32 rand;
662 mpl_dbg(sta->sdata,
663 "Mesh plink for %pM (retry, timeout): %d %d\n",
664 sta->sta.addr, sta->mesh->plink_retries,
665 sta->mesh->plink_timeout);
666 get_random_bytes(&rand, sizeof(u32));
667 sta->mesh->plink_timeout = sta->mesh->plink_timeout +
668 rand % sta->mesh->plink_timeout;
669 ++sta->mesh->plink_retries;
670 mod_plink_timer(sta, sta->mesh->plink_timeout);
671 action = WLAN_SP_MESH_PEERING_OPEN;
672 break;
673 }
674 reason = WLAN_REASON_MESH_MAX_RETRIES;
675 /* fall through on else */
676 case NL80211_PLINK_CNF_RCVD:
677 /* confirm timer */
678 if (!reason)
679 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT;
680 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
681 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
682 action = WLAN_SP_MESH_PEERING_CLOSE;
683 break;
684 case NL80211_PLINK_HOLDING:
685 /* holding timer */
686 del_timer(&sta->mesh->plink_timer);
687 mesh_plink_fsm_restart(sta);
688 break;
689 default:
690 break;
691 }
692 spin_unlock_bh(&sta->mesh->plink_lock);
693 if (action)
694 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
695 sta->mesh->llid, sta->mesh->plid, reason);
696 }
697
698 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout)
699 {
700 sta->mesh->plink_timer.expires = jiffies + msecs_to_jiffies(timeout);
701 sta->mesh->plink_timer.data = (unsigned long) sta;
702 sta->mesh->plink_timer.function = mesh_plink_timer;
703 sta->mesh->plink_timeout = timeout;
704 add_timer(&sta->mesh->plink_timer);
705 }
706
707 static bool llid_in_use(struct ieee80211_sub_if_data *sdata,
708 u16 llid)
709 {
710 struct ieee80211_local *local = sdata->local;
711 bool in_use = false;
712 struct sta_info *sta;
713
714 rcu_read_lock();
715 list_for_each_entry_rcu(sta, &local->sta_list, list) {
716 if (sdata != sta->sdata)
717 continue;
718
719 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) {
720 in_use = true;
721 break;
722 }
723 }
724 rcu_read_unlock();
725
726 return in_use;
727 }
728
729 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata)
730 {
731 u16 llid;
732
733 do {
734 get_random_bytes(&llid, sizeof(llid));
735 } while (llid_in_use(sdata, llid));
736
737 return llid;
738 }
739
740 u32 mesh_plink_open(struct sta_info *sta)
741 {
742 struct ieee80211_sub_if_data *sdata = sta->sdata;
743 u32 changed;
744
745 if (!test_sta_flag(sta, WLAN_STA_AUTH))
746 return 0;
747
748 spin_lock_bh(&sta->mesh->plink_lock);
749 sta->mesh->llid = mesh_get_new_llid(sdata);
750 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN &&
751 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) {
752 spin_unlock_bh(&sta->mesh->plink_lock);
753 return 0;
754 }
755 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT;
756 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
757 spin_unlock_bh(&sta->mesh->plink_lock);
758 mpl_dbg(sdata,
759 "Mesh plink: starting establishment with %pM\n",
760 sta->sta.addr);
761
762 /* set the non-peer mode to active during peering */
763 changed = ieee80211_mps_local_status_update(sdata);
764
765 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN,
766 sta->sta.addr, sta->mesh->llid, 0, 0);
767 return changed;
768 }
769
770 u32 mesh_plink_block(struct sta_info *sta)
771 {
772 u32 changed;
773
774 spin_lock_bh(&sta->mesh->plink_lock);
775 changed = __mesh_plink_deactivate(sta);
776 sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
777 spin_unlock_bh(&sta->mesh->plink_lock);
778 mesh_path_flush_by_nexthop(sta);
779
780 return changed;
781 }
782
783 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata,
784 struct sta_info *sta,
785 enum plink_event event)
786 {
787 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
788 u16 reason = (event == CLS_ACPT) ?
789 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG;
790
791 sta->mesh->reason = reason;
792 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
793 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
794 }
795
796 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata,
797 struct sta_info *sta)
798 {
799 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
800 u32 changed = 0;
801
802 del_timer(&sta->mesh->plink_timer);
803 sta->mesh->plink_state = NL80211_PLINK_ESTAB;
804 changed |= mesh_plink_inc_estab_count(sdata);
805 changed |= mesh_set_ht_prot_mode(sdata);
806 changed |= mesh_set_short_slot_time(sdata);
807 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr);
808 ieee80211_mps_sta_status_update(sta);
809 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode);
810 return changed;
811 }
812
813 /**
814 * mesh_plink_fsm - step @sta MPM based on @event
815 *
816 * @sdata: interface
817 * @sta: mesh neighbor
818 * @event: peering event
819 *
820 * Return: changed MBSS flags
821 */
822 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata,
823 struct sta_info *sta, enum plink_event event)
824 {
825 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
826 enum ieee80211_self_protected_actioncode action = 0;
827 u32 changed = 0;
828 bool flush = false;
829
830 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr,
831 mplstates[sta->mesh->plink_state], mplevents[event]);
832
833 spin_lock_bh(&sta->mesh->plink_lock);
834 switch (sta->mesh->plink_state) {
835 case NL80211_PLINK_LISTEN:
836 switch (event) {
837 case CLS_ACPT:
838 mesh_plink_fsm_restart(sta);
839 break;
840 case OPN_ACPT:
841 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
842 sta->mesh->llid = mesh_get_new_llid(sdata);
843 mesh_plink_timer_set(sta,
844 mshcfg->dot11MeshRetryTimeout);
845
846 /* set the non-peer mode to active during peering */
847 changed |= ieee80211_mps_local_status_update(sdata);
848 action = WLAN_SP_MESH_PEERING_OPEN;
849 break;
850 default:
851 break;
852 }
853 break;
854 case NL80211_PLINK_OPN_SNT:
855 switch (event) {
856 case OPN_RJCT:
857 case CNF_RJCT:
858 case CLS_ACPT:
859 mesh_plink_close(sdata, sta, event);
860 action = WLAN_SP_MESH_PEERING_CLOSE;
861 break;
862 case OPN_ACPT:
863 /* retry timer is left untouched */
864 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
865 action = WLAN_SP_MESH_PEERING_CONFIRM;
866 break;
867 case CNF_ACPT:
868 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD;
869 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout);
870 break;
871 default:
872 break;
873 }
874 break;
875 case NL80211_PLINK_OPN_RCVD:
876 switch (event) {
877 case OPN_RJCT:
878 case CNF_RJCT:
879 case CLS_ACPT:
880 mesh_plink_close(sdata, sta, event);
881 action = WLAN_SP_MESH_PEERING_CLOSE;
882 break;
883 case OPN_ACPT:
884 action = WLAN_SP_MESH_PEERING_CONFIRM;
885 break;
886 case CNF_ACPT:
887 changed |= mesh_plink_establish(sdata, sta);
888 break;
889 default:
890 break;
891 }
892 break;
893 case NL80211_PLINK_CNF_RCVD:
894 switch (event) {
895 case OPN_RJCT:
896 case CNF_RJCT:
897 case CLS_ACPT:
898 mesh_plink_close(sdata, sta, event);
899 action = WLAN_SP_MESH_PEERING_CLOSE;
900 break;
901 case OPN_ACPT:
902 changed |= mesh_plink_establish(sdata, sta);
903 action = WLAN_SP_MESH_PEERING_CONFIRM;
904 break;
905 default:
906 break;
907 }
908 break;
909 case NL80211_PLINK_ESTAB:
910 switch (event) {
911 case CLS_ACPT:
912 changed |= __mesh_plink_deactivate(sta);
913 changed |= mesh_set_ht_prot_mode(sdata);
914 changed |= mesh_set_short_slot_time(sdata);
915 mesh_plink_close(sdata, sta, event);
916 action = WLAN_SP_MESH_PEERING_CLOSE;
917 flush = true;
918 break;
919 case OPN_ACPT:
920 action = WLAN_SP_MESH_PEERING_CONFIRM;
921 break;
922 default:
923 break;
924 }
925 break;
926 case NL80211_PLINK_HOLDING:
927 switch (event) {
928 case CLS_ACPT:
929 del_timer(&sta->mesh->plink_timer);
930 mesh_plink_fsm_restart(sta);
931 break;
932 case OPN_ACPT:
933 case CNF_ACPT:
934 case OPN_RJCT:
935 case CNF_RJCT:
936 action = WLAN_SP_MESH_PEERING_CLOSE;
937 break;
938 default:
939 break;
940 }
941 break;
942 default:
943 /* should not get here, PLINK_BLOCKED is dealt with at the
944 * beginning of the function
945 */
946 break;
947 }
948 spin_unlock_bh(&sta->mesh->plink_lock);
949 if (flush)
950 mesh_path_flush_by_nexthop(sta);
951 if (action) {
952 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
953 sta->mesh->llid, sta->mesh->plid,
954 sta->mesh->reason);
955
956 /* also send confirm in open case */
957 if (action == WLAN_SP_MESH_PEERING_OPEN) {
958 mesh_plink_frame_tx(sdata, sta,
959 WLAN_SP_MESH_PEERING_CONFIRM,
960 sta->sta.addr, sta->mesh->llid,
961 sta->mesh->plid, 0);
962 }
963 }
964
965 return changed;
966 }
967
968 /*
969 * mesh_plink_get_event - get correct MPM event
970 *
971 * @sdata: interface
972 * @sta: peer, leave NULL if processing a frame from a new suitable peer
973 * @elems: peering management IEs
974 * @ftype: frame type
975 * @llid: peer's peer link ID
976 * @plid: peer's local link ID
977 *
978 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as
979 * an error.
980 */
981 static enum plink_event
982 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata,
983 struct sta_info *sta,
984 struct ieee802_11_elems *elems,
985 enum ieee80211_self_protected_actioncode ftype,
986 u16 llid, u16 plid)
987 {
988 enum plink_event event = PLINK_UNDEFINED;
989 u8 ie_len = elems->peering_len;
990 bool matches_local;
991
992 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE ||
993 mesh_matches_local(sdata, elems));
994
995 /* deny open request from non-matching peer */
996 if (!matches_local && !sta) {
997 event = OPN_RJCT;
998 goto out;
999 }
1000
1001 if (!sta) {
1002 if (ftype != WLAN_SP_MESH_PEERING_OPEN) {
1003 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
1004 goto out;
1005 }
1006 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
1007 if (!mesh_plink_free_count(sdata)) {
1008 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
1009 goto out;
1010 }
1011
1012 /* new matching peer */
1013 event = OPN_ACPT;
1014 goto out;
1015 } else {
1016 if (!test_sta_flag(sta, WLAN_STA_AUTH)) {
1017 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
1018 goto out;
1019 }
1020 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED)
1021 goto out;
1022 }
1023
1024 switch (ftype) {
1025 case WLAN_SP_MESH_PEERING_OPEN:
1026 if (!matches_local)
1027 event = OPN_RJCT;
1028 if (!mesh_plink_free_count(sdata) ||
1029 (sta->mesh->plid && sta->mesh->plid != plid))
1030 event = OPN_IGNR;
1031 else
1032 event = OPN_ACPT;
1033 break;
1034 case WLAN_SP_MESH_PEERING_CONFIRM:
1035 if (!matches_local)
1036 event = CNF_RJCT;
1037 if (!mesh_plink_free_count(sdata) ||
1038 sta->mesh->llid != llid ||
1039 (sta->mesh->plid && sta->mesh->plid != plid))
1040 event = CNF_IGNR;
1041 else
1042 event = CNF_ACPT;
1043 break;
1044 case WLAN_SP_MESH_PEERING_CLOSE:
1045 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
1046 /* Do not check for llid or plid. This does not
1047 * follow the standard but since multiple plinks
1048 * per sta are not supported, it is necessary in
1049 * order to avoid a livelock when MP A sees an
1050 * establish peer link to MP B but MP B does not
1051 * see it. This can be caused by a timeout in
1052 * B's peer link establishment or B beign
1053 * restarted.
1054 */
1055 event = CLS_ACPT;
1056 else if (sta->mesh->plid != plid)
1057 event = CLS_IGNR;
1058 else if (ie_len == 8 && sta->mesh->llid != llid)
1059 event = CLS_IGNR;
1060 else
1061 event = CLS_ACPT;
1062 break;
1063 default:
1064 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
1065 break;
1066 }
1067
1068 out:
1069 return event;
1070 }
1071
1072 static void
1073 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
1074 struct ieee80211_mgmt *mgmt,
1075 struct ieee802_11_elems *elems)
1076 {
1077
1078 struct sta_info *sta;
1079 enum plink_event event;
1080 enum ieee80211_self_protected_actioncode ftype;
1081 u32 changed = 0;
1082 u8 ie_len = elems->peering_len;
1083 u16 plid, llid = 0;
1084
1085 if (!elems->peering) {
1086 mpl_dbg(sdata,
1087 "Mesh plink: missing necessary peer link ie\n");
1088 return;
1089 }
1090
1091 if (elems->rsn_len &&
1092 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
1093 mpl_dbg(sdata,
1094 "Mesh plink: can't establish link with secure peer\n");
1095 return;
1096 }
1097
1098 ftype = mgmt->u.action.u.self_prot.action_code;
1099 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
1100 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
1101 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
1102 && ie_len != 8)) {
1103 mpl_dbg(sdata,
1104 "Mesh plink: incorrect plink ie length %d %d\n",
1105 ftype, ie_len);
1106 return;
1107 }
1108
1109 if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
1110 (!elems->mesh_id || !elems->mesh_config)) {
1111 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
1112 return;
1113 }
1114 /* Note the lines below are correct, the llid in the frame is the plid
1115 * from the point of view of this host.
1116 */
1117 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering));
1118 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
1119 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
1120 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering));
1121
1122 /* WARNING: Only for sta pointer, is dropped & re-acquired */
1123 rcu_read_lock();
1124
1125 sta = sta_info_get(sdata, mgmt->sa);
1126
1127 if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
1128 !rssi_threshold_check(sdata, sta)) {
1129 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
1130 mgmt->sa);
1131 goto unlock_rcu;
1132 }
1133
1134 /* Now we will figure out the appropriate event... */
1135 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid);
1136
1137 if (event == OPN_ACPT) {
1138 rcu_read_unlock();
1139 /* allocate sta entry if necessary and update info */
1140 sta = mesh_sta_info_get(sdata, mgmt->sa, elems);
1141 if (!sta) {
1142 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
1143 goto unlock_rcu;
1144 }
1145 sta->mesh->plid = plid;
1146 } else if (!sta && event == OPN_RJCT) {
1147 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE,
1148 mgmt->sa, 0, plid,
1149 WLAN_REASON_MESH_CONFIG);
1150 goto unlock_rcu;
1151 } else if (!sta || event == PLINK_UNDEFINED) {
1152 /* something went wrong */
1153 goto unlock_rcu;
1154 }
1155
1156 if (event == CNF_ACPT) {
1157 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */
1158 if (!sta->mesh->plid)
1159 sta->mesh->plid = plid;
1160
1161 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt));
1162 }
1163
1164 changed |= mesh_plink_fsm(sdata, sta, event);
1165
1166 unlock_rcu:
1167 rcu_read_unlock();
1168
1169 if (changed)
1170 ieee80211_mbss_info_change_notify(sdata, changed);
1171 }
1172
1173 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
1174 struct ieee80211_mgmt *mgmt, size_t len,
1175 struct ieee80211_rx_status *rx_status)
1176 {
1177 struct ieee802_11_elems elems;
1178 size_t baselen;
1179 u8 *baseaddr;
1180
1181 /* need action_code, aux */
1182 if (len < IEEE80211_MIN_ACTION_SIZE + 3)
1183 return;
1184
1185 if (sdata->u.mesh.user_mpm)
1186 /* userspace must register for these */
1187 return;
1188
1189 if (is_multicast_ether_addr(mgmt->da)) {
1190 mpl_dbg(sdata,
1191 "Mesh plink: ignore frame from multicast address\n");
1192 return;
1193 }
1194
1195 baseaddr = mgmt->u.action.u.self_prot.variable;
1196 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
1197 if (mgmt->u.action.u.self_prot.action_code ==
1198 WLAN_SP_MESH_PEERING_CONFIRM) {
1199 baseaddr += 4;
1200 baselen += 4;
1201
1202 if (baselen > len)
1203 return;
1204 }
1205 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems);
1206 mesh_process_plink_frame(sdata, mgmt, &elems);
1207 }
Linux with added FPC-III support