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Linux 4.1.16
[linux/fpc-iii.git] / net / mac80211 / mesh_plink.c
blob60d737f144e37563ebfaa9f7c82efafc3e2c9135
1 /*
2 * Copyright (c) 2008, 2009 open80211s Ltd.
3 * Author: Luis Carlos Cobo <luisca@cozybit.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9 #include <linux/gfp.h>
10 #include <linux/kernel.h>
11 #include <linux/random.h>
12 #include "ieee80211_i.h"
13 #include "rate.h"
14 #include "mesh.h"
15
16 #define PLINK_GET_LLID(p) (p + 2)
17 #define PLINK_GET_PLID(p) (p + 4)
18
19 #define mod_plink_timer(s, t) (mod_timer(&s->plink_timer, \
20 jiffies + msecs_to_jiffies(t)))
21
22 enum plink_event {
23 PLINK_UNDEFINED,
24 OPN_ACPT,
25 OPN_RJCT,
26 OPN_IGNR,
27 CNF_ACPT,
28 CNF_RJCT,
29 CNF_IGNR,
30 CLS_ACPT,
31 CLS_IGNR
32 };
33
34 static const char * const mplstates[] = {
35 [NL80211_PLINK_LISTEN] = "LISTEN",
36 [NL80211_PLINK_OPN_SNT] = "OPN-SNT",
37 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
38 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
39 [NL80211_PLINK_ESTAB] = "ESTAB",
40 [NL80211_PLINK_HOLDING] = "HOLDING",
41 [NL80211_PLINK_BLOCKED] = "BLOCKED"
42 };
43
44 static const char * const mplevents[] = {
45 [PLINK_UNDEFINED] = "NONE",
46 [OPN_ACPT] = "OPN_ACPT",
47 [OPN_RJCT] = "OPN_RJCT",
48 [OPN_IGNR] = "OPN_IGNR",
49 [CNF_ACPT] = "CNF_ACPT",
50 [CNF_RJCT] = "CNF_RJCT",
51 [CNF_IGNR] = "CNF_IGNR",
52 [CLS_ACPT] = "CLS_ACPT",
53 [CLS_IGNR] = "CLS_IGNR"
54 };
55
56 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
57 enum ieee80211_self_protected_actioncode action,
58 u8 *da, u16 llid, u16 plid, u16 reason);
59
60
61 /* We only need a valid sta if user configured a minimum rssi_threshold. */
62 static bool rssi_threshold_check(struct ieee80211_sub_if_data *sdata,
63 struct sta_info *sta)
64 {
65 s32 rssi_threshold = sdata->u.mesh.mshcfg.rssi_threshold;
66 return rssi_threshold == 0 ||
67 (sta && (s8) -ewma_read(&sta->avg_signal) > 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->lock
76 */
77 static inline void mesh_plink_fsm_restart(struct sta_info *sta)
78 {
79 sta->plink_state = NL80211_PLINK_LISTEN;
80 sta->llid = sta->plid = sta->reason = 0;
81 sta->plink_retries = 0;
82 }
83
84 /*
85 * mesh_set_short_slot_time - enable / disable ERP short slot time.
86 *
87 * The standard indirectly mandates mesh STAs to turn off short slot time by
88 * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we
89 * can't be sneaky about it. Enable short slot time if all mesh STAs in the
90 * MBSS support ERP rates.
91 *
92 * Returns BSS_CHANGED_ERP_SLOT or 0 for no change.
93 */
94 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata)
95 {
96 struct ieee80211_local *local = sdata->local;
97 enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
98 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
99 struct sta_info *sta;
100 u32 erp_rates = 0, changed = 0;
101 int i;
102 bool short_slot = false;
103
104 if (band == IEEE80211_BAND_5GHZ) {
105 /* (IEEE 802.11-2012 19.4.5) */
106 short_slot = true;
107 goto out;
108 } else if (band != IEEE80211_BAND_2GHZ ||
109 (band == IEEE80211_BAND_2GHZ &&
110 local->hw.flags & IEEE80211_HW_2GHZ_SHORT_SLOT_INCAPABLE))
111 goto out;
112
113 for (i = 0; i < sband->n_bitrates; i++)
114 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)
115 erp_rates |= BIT(i);
116
117 if (!erp_rates)
118 goto out;
119
120 rcu_read_lock();
121 list_for_each_entry_rcu(sta, &local->sta_list, list) {
122 if (sdata != sta->sdata ||
123 sta->plink_state != NL80211_PLINK_ESTAB)
124 continue;
125
126 short_slot = false;
127 if (erp_rates & sta->sta.supp_rates[band])
128 short_slot = true;
129 else
130 break;
131 }
132 rcu_read_unlock();
133
134 out:
135 if (sdata->vif.bss_conf.use_short_slot != short_slot) {
136 sdata->vif.bss_conf.use_short_slot = short_slot;
137 changed = BSS_CHANGED_ERP_SLOT;
138 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n",
139 sdata->vif.addr, short_slot);
140 }
141 return changed;
142 }
143
144 /**
145 * mesh_set_ht_prot_mode - set correct HT protection mode
146 *
147 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
148 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
149 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
150 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode
151 * is selected if all peers in our 20/40MHz MBSS support HT and atleast one
152 * HT20 peer is present. Otherwise no-protection mode is selected.
153 */
154 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
155 {
156 struct ieee80211_local *local = sdata->local;
157 struct sta_info *sta;
158 u16 ht_opmode;
159 bool non_ht_sta = false, ht20_sta = false;
160
161 switch (sdata->vif.bss_conf.chandef.width) {
162 case NL80211_CHAN_WIDTH_20_NOHT:
163 case NL80211_CHAN_WIDTH_5:
164 case NL80211_CHAN_WIDTH_10:
165 return 0;
166 default:
167 break;
168 }
169
170 rcu_read_lock();
171 list_for_each_entry_rcu(sta, &local->sta_list, list) {
172 if (sdata != sta->sdata ||
173 sta->plink_state != NL80211_PLINK_ESTAB)
174 continue;
175
176 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20)
177 continue;
178
179 if (!sta->sta.ht_cap.ht_supported) {
180 mpl_dbg(sdata, "nonHT sta (%pM) is present\n",
181 sta->sta.addr);
182 non_ht_sta = true;
183 break;
184 }
185
186 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr);
187 ht20_sta = true;
188 }
189 rcu_read_unlock();
190
191 if (non_ht_sta)
192 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
193 else if (ht20_sta &&
194 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20)
195 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
196 else
197 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
198
199 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode)
200 return 0;
201
202 sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
203 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
204 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode);
205 return BSS_CHANGED_HT;
206 }
207
208 /**
209 * __mesh_plink_deactivate - deactivate mesh peer link
210 *
211 * @sta: mesh peer link to deactivate
212 *
213 * All mesh paths with this peer as next hop will be flushed
214 * Returns beacon changed flag if the beacon content changed.
215 *
216 * Locking: the caller must hold sta->lock
217 */
218 static u32 __mesh_plink_deactivate(struct sta_info *sta)
219 {
220 struct ieee80211_sub_if_data *sdata = sta->sdata;
221 u32 changed = 0;
222
223 if (sta->plink_state == NL80211_PLINK_ESTAB)
224 changed = mesh_plink_dec_estab_count(sdata);
225 sta->plink_state = NL80211_PLINK_BLOCKED;
226 mesh_path_flush_by_nexthop(sta);
227
228 ieee80211_mps_sta_status_update(sta);
229 changed |= ieee80211_mps_set_sta_local_pm(sta,
230 NL80211_MESH_POWER_UNKNOWN);
231
232 return changed;
233 }
234
235 /**
236 * mesh_plink_deactivate - deactivate mesh peer link
237 *
238 * @sta: mesh peer link to deactivate
239 *
240 * All mesh paths with this peer as next hop will be flushed
241 */
242 u32 mesh_plink_deactivate(struct sta_info *sta)
243 {
244 struct ieee80211_sub_if_data *sdata = sta->sdata;
245 u32 changed;
246
247 spin_lock_bh(&sta->lock);
248 changed = __mesh_plink_deactivate(sta);
249 sta->reason = WLAN_REASON_MESH_PEER_CANCELED;
250 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
251 sta->sta.addr, sta->llid, sta->plid,
252 sta->reason);
253 spin_unlock_bh(&sta->lock);
254
255 return changed;
256 }
257
258 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
259 enum ieee80211_self_protected_actioncode action,
260 u8 *da, u16 llid, u16 plid, u16 reason)
261 {
262 struct ieee80211_local *local = sdata->local;
263 struct sk_buff *skb;
264 struct ieee80211_tx_info *info;
265 struct ieee80211_mgmt *mgmt;
266 bool include_plid = false;
267 u16 peering_proto = 0;
268 u8 *pos, ie_len = 4;
269 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) +
270 sizeof(mgmt->u.action.u.self_prot);
271 int err = -ENOMEM;
272
273 skb = dev_alloc_skb(local->tx_headroom +
274 hdr_len +
275 2 + /* capability info */
276 2 + /* AID */
277 2 + 8 + /* supported rates */
278 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
279 2 + sdata->u.mesh.mesh_id_len +
280 2 + sizeof(struct ieee80211_meshconf_ie) +
281 2 + sizeof(struct ieee80211_ht_cap) +
282 2 + sizeof(struct ieee80211_ht_operation) +
283 2 + 8 + /* peering IE */
284 sdata->u.mesh.ie_len);
285 if (!skb)
286 return err;
287 info = IEEE80211_SKB_CB(skb);
288 skb_reserve(skb, local->tx_headroom);
289 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
290 memset(mgmt, 0, hdr_len);
291 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
292 IEEE80211_STYPE_ACTION);
293 memcpy(mgmt->da, da, ETH_ALEN);
294 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
295 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
296 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
297 mgmt->u.action.u.self_prot.action_code = action;
298
299 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
300 enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
301
302 /* capability info */
303 pos = skb_put(skb, 2);
304 memset(pos, 0, 2);
305 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
306 /* AID */
307 pos = skb_put(skb, 2);
308 put_unaligned_le16(plid, pos + 2);
309 }
310 if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
311 ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
312 mesh_add_rsn_ie(sdata, skb) ||
313 mesh_add_meshid_ie(sdata, skb) ||
314 mesh_add_meshconf_ie(sdata, skb))
315 goto free;
316 } else { /* WLAN_SP_MESH_PEERING_CLOSE */
317 info->flags |= IEEE80211_TX_CTL_NO_ACK;
318 if (mesh_add_meshid_ie(sdata, skb))
319 goto free;
320 }
321
322 /* Add Mesh Peering Management element */
323 switch (action) {
324 case WLAN_SP_MESH_PEERING_OPEN:
325 break;
326 case WLAN_SP_MESH_PEERING_CONFIRM:
327 ie_len += 2;
328 include_plid = true;
329 break;
330 case WLAN_SP_MESH_PEERING_CLOSE:
331 if (plid) {
332 ie_len += 2;
333 include_plid = true;
334 }
335 ie_len += 2; /* reason code */
336 break;
337 default:
338 err = -EINVAL;
339 goto free;
340 }
341
342 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
343 goto free;
344
345 pos = skb_put(skb, 2 + ie_len);
346 *pos++ = WLAN_EID_PEER_MGMT;
347 *pos++ = ie_len;
348 memcpy(pos, &peering_proto, 2);
349 pos += 2;
350 put_unaligned_le16(llid, pos);
351 pos += 2;
352 if (include_plid) {
353 put_unaligned_le16(plid, pos);
354 pos += 2;
355 }
356 if (action == WLAN_SP_MESH_PEERING_CLOSE) {
357 put_unaligned_le16(reason, pos);
358 pos += 2;
359 }
360
361 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
362 if (mesh_add_ht_cap_ie(sdata, skb) ||
363 mesh_add_ht_oper_ie(sdata, skb))
364 goto free;
365 }
366
367 if (mesh_add_vendor_ies(sdata, skb))
368 goto free;
369
370 ieee80211_tx_skb(sdata, skb);
371 return 0;
372 free:
373 kfree_skb(skb);
374 return err;
375 }
376
377 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
378 struct sta_info *sta,
379 struct ieee802_11_elems *elems, bool insert)
380 {
381 struct ieee80211_local *local = sdata->local;
382 enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
383 struct ieee80211_supported_band *sband;
384 u32 rates, basic_rates = 0, changed = 0;
385 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth;
386
387 sband = local->hw.wiphy->bands[band];
388 rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates);
389
390 spin_lock_bh(&sta->lock);
391 sta->last_rx = jiffies;
392
393 /* rates and capabilities don't change during peering */
394 if (sta->plink_state == NL80211_PLINK_ESTAB)
395 goto out;
396
397 if (sta->sta.supp_rates[band] != rates)
398 changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
399 sta->sta.supp_rates[band] = rates;
400
401 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
402 elems->ht_cap_elem, sta))
403 changed |= IEEE80211_RC_BW_CHANGED;
404
405 if (bw != sta->sta.bandwidth)
406 changed |= IEEE80211_RC_BW_CHANGED;
407
408 /* HT peer is operating 20MHz-only */
409 if (elems->ht_operation &&
410 !(elems->ht_operation->ht_param &
411 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
412 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20)
413 changed |= IEEE80211_RC_BW_CHANGED;
414 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20;
415 }
416
417 if (insert)
418 rate_control_rate_init(sta);
419 else
420 rate_control_rate_update(local, sband, sta, changed);
421 out:
422 spin_unlock_bh(&sta->lock);
423 }
424
425 static struct sta_info *
426 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
427 {
428 struct sta_info *sta;
429
430 if (sdata->local->num_sta >= MESH_MAX_PLINKS)
431 return NULL;
432
433 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
434 if (!sta)
435 return NULL;
436
437 sta->plink_state = NL80211_PLINK_LISTEN;
438 sta->sta.wme = true;
439
440 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
441 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
442 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
443
444 return sta;
445 }
446
447 static struct sta_info *
448 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
449 struct ieee802_11_elems *elems)
450 {
451 struct sta_info *sta = NULL;
452
453 /* Userspace handles station allocation */
454 if (sdata->u.mesh.user_mpm ||
455 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED)
456 cfg80211_notify_new_peer_candidate(sdata->dev, addr,
457 elems->ie_start,
458 elems->total_len,
459 GFP_KERNEL);
460 else
461 sta = __mesh_sta_info_alloc(sdata, addr);
462
463 return sta;
464 }
465
466 /*
467 * mesh_sta_info_get - return mesh sta info entry for @addr.
468 *
469 * @sdata: local meshif
470 * @addr: peer's address
471 * @elems: IEs from beacon or mesh peering frame.
472 *
473 * Return existing or newly allocated sta_info under RCU read lock.
474 * (re)initialize with given IEs.
475 */
476 static struct sta_info *
477 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
478 u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU)
479 {
480 struct sta_info *sta = NULL;
481
482 rcu_read_lock();
483 sta = sta_info_get(sdata, addr);
484 if (sta) {
485 mesh_sta_info_init(sdata, sta, elems, false);
486 } else {
487 rcu_read_unlock();
488 /* can't run atomic */
489 sta = mesh_sta_info_alloc(sdata, addr, elems);
490 if (!sta) {
491 rcu_read_lock();
492 return NULL;
493 }
494
495 mesh_sta_info_init(sdata, sta, elems, true);
496
497 if (sta_info_insert_rcu(sta))
498 return NULL;
499 }
500
501 return sta;
502 }
503
504 /*
505 * mesh_neighbour_update - update or initialize new mesh neighbor.
506 *
507 * @sdata: local meshif
508 * @addr: peer's address
509 * @elems: IEs from beacon or mesh peering frame
510 *
511 * Initiates peering if appropriate.
512 */
513 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
514 u8 *hw_addr,
515 struct ieee802_11_elems *elems)
516 {
517 struct sta_info *sta;
518 u32 changed = 0;
519
520 sta = mesh_sta_info_get(sdata, hw_addr, elems);
521 if (!sta)
522 goto out;
523
524 if (mesh_peer_accepts_plinks(elems) &&
525 sta->plink_state == NL80211_PLINK_LISTEN &&
526 sdata->u.mesh.accepting_plinks &&
527 sdata->u.mesh.mshcfg.auto_open_plinks &&
528 rssi_threshold_check(sdata, sta))
529 changed = mesh_plink_open(sta);
530
531 ieee80211_mps_frame_release(sta, elems);
532 out:
533 rcu_read_unlock();
534 ieee80211_mbss_info_change_notify(sdata, changed);
535 }
536
537 static void mesh_plink_timer(unsigned long data)
538 {
539 struct sta_info *sta;
540 u16 reason = 0;
541 struct ieee80211_sub_if_data *sdata;
542 struct mesh_config *mshcfg;
543 enum ieee80211_self_protected_actioncode action = 0;
544
545 /*
546 * This STA is valid because sta_info_destroy() will
547 * del_timer_sync() this timer after having made sure
548 * it cannot be readded (by deleting the plink.)
549 */
550 sta = (struct sta_info *) data;
551
552 if (sta->sdata->local->quiescing)
553 return;
554
555 spin_lock_bh(&sta->lock);
556
557 /* If a timer fires just before a state transition on another CPU,
558 * we may have already extended the timeout and changed state by the
559 * time we've acquired the lock and arrived here. In that case,
560 * skip this timer and wait for the new one.
561 */
562 if (time_before(jiffies, sta->plink_timer.expires)) {
563 mpl_dbg(sta->sdata,
564 "Ignoring timer for %pM in state %s (timer adjusted)",
565 sta->sta.addr, mplstates[sta->plink_state]);
566 spin_unlock_bh(&sta->lock);
567 return;
568 }
569
570 /* del_timer() and handler may race when entering these states */
571 if (sta->plink_state == NL80211_PLINK_LISTEN ||
572 sta->plink_state == NL80211_PLINK_ESTAB) {
573 mpl_dbg(sta->sdata,
574 "Ignoring timer for %pM in state %s (timer deleted)",
575 sta->sta.addr, mplstates[sta->plink_state]);
576 spin_unlock_bh(&sta->lock);
577 return;
578 }
579
580 mpl_dbg(sta->sdata,
581 "Mesh plink timer for %pM fired on state %s\n",
582 sta->sta.addr, mplstates[sta->plink_state]);
583 sdata = sta->sdata;
584 mshcfg = &sdata->u.mesh.mshcfg;
585
586 switch (sta->plink_state) {
587 case NL80211_PLINK_OPN_RCVD:
588 case NL80211_PLINK_OPN_SNT:
589 /* retry timer */
590 if (sta->plink_retries < mshcfg->dot11MeshMaxRetries) {
591 u32 rand;
592 mpl_dbg(sta->sdata,
593 "Mesh plink for %pM (retry, timeout): %d %d\n",
594 sta->sta.addr, sta->plink_retries,
595 sta->plink_timeout);
596 get_random_bytes(&rand, sizeof(u32));
597 sta->plink_timeout = sta->plink_timeout +
598 rand % sta->plink_timeout;
599 ++sta->plink_retries;
600 mod_plink_timer(sta, sta->plink_timeout);
601 action = WLAN_SP_MESH_PEERING_OPEN;
602 break;
603 }
604 reason = WLAN_REASON_MESH_MAX_RETRIES;
605 /* fall through on else */
606 case NL80211_PLINK_CNF_RCVD:
607 /* confirm timer */
608 if (!reason)
609 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT;
610 sta->plink_state = NL80211_PLINK_HOLDING;
611 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
612 action = WLAN_SP_MESH_PEERING_CLOSE;
613 break;
614 case NL80211_PLINK_HOLDING:
615 /* holding timer */
616 del_timer(&sta->plink_timer);
617 mesh_plink_fsm_restart(sta);
618 break;
619 default:
620 break;
621 }
622 spin_unlock_bh(&sta->lock);
623 if (action)
624 mesh_plink_frame_tx(sdata, action, sta->sta.addr,
625 sta->llid, sta->plid, reason);
626 }
627
628 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout)
629 {
630 sta->plink_timer.expires = jiffies + msecs_to_jiffies(timeout);
631 sta->plink_timer.data = (unsigned long) sta;
632 sta->plink_timer.function = mesh_plink_timer;
633 sta->plink_timeout = timeout;
634 add_timer(&sta->plink_timer);
635 }
636
637 static bool llid_in_use(struct ieee80211_sub_if_data *sdata,
638 u16 llid)
639 {
640 struct ieee80211_local *local = sdata->local;
641 bool in_use = false;
642 struct sta_info *sta;
643
644 rcu_read_lock();
645 list_for_each_entry_rcu(sta, &local->sta_list, list) {
646 if (!memcmp(&sta->llid, &llid, sizeof(llid))) {
647 in_use = true;
648 break;
649 }
650 }
651 rcu_read_unlock();
652
653 return in_use;
654 }
655
656 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata)
657 {
658 u16 llid;
659
660 do {
661 get_random_bytes(&llid, sizeof(llid));
662 /* for mesh PS we still only have the AID range for TIM bits */
663 llid = (llid % IEEE80211_MAX_AID) + 1;
664 } while (llid_in_use(sdata, llid));
665
666 return llid;
667 }
668
669 u32 mesh_plink_open(struct sta_info *sta)
670 {
671 struct ieee80211_sub_if_data *sdata = sta->sdata;
672 u32 changed;
673
674 if (!test_sta_flag(sta, WLAN_STA_AUTH))
675 return 0;
676
677 spin_lock_bh(&sta->lock);
678 sta->llid = mesh_get_new_llid(sdata);
679 if (sta->plink_state != NL80211_PLINK_LISTEN &&
680 sta->plink_state != NL80211_PLINK_BLOCKED) {
681 spin_unlock_bh(&sta->lock);
682 return 0;
683 }
684 sta->plink_state = NL80211_PLINK_OPN_SNT;
685 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
686 spin_unlock_bh(&sta->lock);
687 mpl_dbg(sdata,
688 "Mesh plink: starting establishment with %pM\n",
689 sta->sta.addr);
690
691 /* set the non-peer mode to active during peering */
692 changed = ieee80211_mps_local_status_update(sdata);
693
694 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
695 sta->sta.addr, sta->llid, 0, 0);
696 return changed;
697 }
698
699 u32 mesh_plink_block(struct sta_info *sta)
700 {
701 u32 changed;
702
703 spin_lock_bh(&sta->lock);
704 changed = __mesh_plink_deactivate(sta);
705 sta->plink_state = NL80211_PLINK_BLOCKED;
706 spin_unlock_bh(&sta->lock);
707
708 return changed;
709 }
710
711 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata,
712 struct sta_info *sta,
713 enum plink_event event)
714 {
715 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
716
717 u16 reason = (event == CLS_ACPT) ?
718 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG;
719
720 sta->reason = reason;
721 sta->plink_state = NL80211_PLINK_HOLDING;
722 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
723 }
724
725 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata,
726 struct sta_info *sta)
727 {
728 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
729 u32 changed = 0;
730
731 del_timer(&sta->plink_timer);
732 sta->plink_state = NL80211_PLINK_ESTAB;
733 changed |= mesh_plink_inc_estab_count(sdata);
734 changed |= mesh_set_ht_prot_mode(sdata);
735 changed |= mesh_set_short_slot_time(sdata);
736 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr);
737 ieee80211_mps_sta_status_update(sta);
738 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode);
739 return changed;
740 }
741
742 /**
743 * mesh_plink_fsm - step @sta MPM based on @event
744 *
745 * @sdata: interface
746 * @sta: mesh neighbor
747 * @event: peering event
748 *
749 * Return: changed MBSS flags
750 */
751 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata,
752 struct sta_info *sta, enum plink_event event)
753 {
754 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
755 enum ieee80211_self_protected_actioncode action = 0;
756 u32 changed = 0;
757
758 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr,
759 mplstates[sta->plink_state], mplevents[event]);
760
761 spin_lock_bh(&sta->lock);
762 switch (sta->plink_state) {
763 case NL80211_PLINK_LISTEN:
764 switch (event) {
765 case CLS_ACPT:
766 mesh_plink_fsm_restart(sta);
767 break;
768 case OPN_ACPT:
769 sta->plink_state = NL80211_PLINK_OPN_RCVD;
770 sta->llid = mesh_get_new_llid(sdata);
771 mesh_plink_timer_set(sta,
772 mshcfg->dot11MeshRetryTimeout);
773
774 /* set the non-peer mode to active during peering */
775 changed |= ieee80211_mps_local_status_update(sdata);
776 action = WLAN_SP_MESH_PEERING_OPEN;
777 break;
778 default:
779 break;
780 }
781 break;
782 case NL80211_PLINK_OPN_SNT:
783 switch (event) {
784 case OPN_RJCT:
785 case CNF_RJCT:
786 case CLS_ACPT:
787 mesh_plink_close(sdata, sta, event);
788 action = WLAN_SP_MESH_PEERING_CLOSE;
789 break;
790 case OPN_ACPT:
791 /* retry timer is left untouched */
792 sta->plink_state = NL80211_PLINK_OPN_RCVD;
793 action = WLAN_SP_MESH_PEERING_CONFIRM;
794 break;
795 case CNF_ACPT:
796 sta->plink_state = NL80211_PLINK_CNF_RCVD;
797 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout);
798 break;
799 default:
800 break;
801 }
802 break;
803 case NL80211_PLINK_OPN_RCVD:
804 switch (event) {
805 case OPN_RJCT:
806 case CNF_RJCT:
807 case CLS_ACPT:
808 mesh_plink_close(sdata, sta, event);
809 action = WLAN_SP_MESH_PEERING_CLOSE;
810 break;
811 case OPN_ACPT:
812 action = WLAN_SP_MESH_PEERING_CONFIRM;
813 break;
814 case CNF_ACPT:
815 changed |= mesh_plink_establish(sdata, sta);
816 break;
817 default:
818 break;
819 }
820 break;
821 case NL80211_PLINK_CNF_RCVD:
822 switch (event) {
823 case OPN_RJCT:
824 case CNF_RJCT:
825 case CLS_ACPT:
826 mesh_plink_close(sdata, sta, event);
827 action = WLAN_SP_MESH_PEERING_CLOSE;
828 break;
829 case OPN_ACPT:
830 changed |= mesh_plink_establish(sdata, sta);
831 action = WLAN_SP_MESH_PEERING_CONFIRM;
832 break;
833 default:
834 break;
835 }
836 break;
837 case NL80211_PLINK_ESTAB:
838 switch (event) {
839 case CLS_ACPT:
840 changed |= __mesh_plink_deactivate(sta);
841 changed |= mesh_set_ht_prot_mode(sdata);
842 changed |= mesh_set_short_slot_time(sdata);
843 mesh_plink_close(sdata, sta, event);
844 action = WLAN_SP_MESH_PEERING_CLOSE;
845 break;
846 case OPN_ACPT:
847 action = WLAN_SP_MESH_PEERING_CONFIRM;
848 break;
849 default:
850 break;
851 }
852 break;
853 case NL80211_PLINK_HOLDING:
854 switch (event) {
855 case CLS_ACPT:
856 del_timer(&sta->plink_timer);
857 mesh_plink_fsm_restart(sta);
858 break;
859 case OPN_ACPT:
860 case CNF_ACPT:
861 case OPN_RJCT:
862 case CNF_RJCT:
863 action = WLAN_SP_MESH_PEERING_CLOSE;
864 break;
865 default:
866 break;
867 }
868 break;
869 default:
870 /* should not get here, PLINK_BLOCKED is dealt with at the
871 * beginning of the function
872 */
873 break;
874 }
875 spin_unlock_bh(&sta->lock);
876 if (action) {
877 mesh_plink_frame_tx(sdata, action, sta->sta.addr,
878 sta->llid, sta->plid, sta->reason);
879
880 /* also send confirm in open case */
881 if (action == WLAN_SP_MESH_PEERING_OPEN) {
882 mesh_plink_frame_tx(sdata,
883 WLAN_SP_MESH_PEERING_CONFIRM,
884 sta->sta.addr, sta->llid,
885 sta->plid, 0);
886 }
887 }
888
889 return changed;
890 }
891
892 /*
893 * mesh_plink_get_event - get correct MPM event
894 *
895 * @sdata: interface
896 * @sta: peer, leave NULL if processing a frame from a new suitable peer
897 * @elems: peering management IEs
898 * @ftype: frame type
899 * @llid: peer's peer link ID
900 * @plid: peer's local link ID
901 *
902 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as
903 * an error.
904 */
905 static enum plink_event
906 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata,
907 struct sta_info *sta,
908 struct ieee802_11_elems *elems,
909 enum ieee80211_self_protected_actioncode ftype,
910 u16 llid, u16 plid)
911 {
912 enum plink_event event = PLINK_UNDEFINED;
913 u8 ie_len = elems->peering_len;
914 bool matches_local;
915
916 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE ||
917 mesh_matches_local(sdata, elems));
918
919 /* deny open request from non-matching peer */
920 if (!matches_local && !sta) {
921 event = OPN_RJCT;
922 goto out;
923 }
924
925 if (!sta) {
926 if (ftype != WLAN_SP_MESH_PEERING_OPEN) {
927 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
928 goto out;
929 }
930 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
931 if (!mesh_plink_free_count(sdata)) {
932 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
933 goto out;
934 }
935 } else {
936 if (!test_sta_flag(sta, WLAN_STA_AUTH)) {
937 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
938 goto out;
939 }
940 if (sta->plink_state == NL80211_PLINK_BLOCKED)
941 goto out;
942 }
943
944 /* new matching peer */
945 if (!sta) {
946 event = OPN_ACPT;
947 goto out;
948 }
949
950 switch (ftype) {
951 case WLAN_SP_MESH_PEERING_OPEN:
952 if (!matches_local)
953 event = OPN_RJCT;
954 if (!mesh_plink_free_count(sdata) ||
955 (sta->plid && sta->plid != plid))
956 event = OPN_IGNR;
957 else
958 event = OPN_ACPT;
959 break;
960 case WLAN_SP_MESH_PEERING_CONFIRM:
961 if (!matches_local)
962 event = CNF_RJCT;
963 if (!mesh_plink_free_count(sdata) ||
964 sta->llid != llid ||
965 (sta->plid && sta->plid != plid))
966 event = CNF_IGNR;
967 else
968 event = CNF_ACPT;
969 break;
970 case WLAN_SP_MESH_PEERING_CLOSE:
971 if (sta->plink_state == NL80211_PLINK_ESTAB)
972 /* Do not check for llid or plid. This does not
973 * follow the standard but since multiple plinks
974 * per sta are not supported, it is necessary in
975 * order to avoid a livelock when MP A sees an
976 * establish peer link to MP B but MP B does not
977 * see it. This can be caused by a timeout in
978 * B's peer link establishment or B beign
979 * restarted.
980 */
981 event = CLS_ACPT;
982 else if (sta->plid != plid)
983 event = CLS_IGNR;
984 else if (ie_len == 8 && sta->llid != llid)
985 event = CLS_IGNR;
986 else
987 event = CLS_ACPT;
988 break;
989 default:
990 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
991 break;
992 }
993
994 out:
995 return event;
996 }
997
998 static void
999 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
1000 struct ieee80211_mgmt *mgmt,
1001 struct ieee802_11_elems *elems)
1002 {
1003
1004 struct sta_info *sta;
1005 enum plink_event event;
1006 enum ieee80211_self_protected_actioncode ftype;
1007 u32 changed = 0;
1008 u8 ie_len = elems->peering_len;
1009 u16 plid, llid = 0;
1010
1011 if (!elems->peering) {
1012 mpl_dbg(sdata,
1013 "Mesh plink: missing necessary peer link ie\n");
1014 return;
1015 }
1016
1017 if (elems->rsn_len &&
1018 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
1019 mpl_dbg(sdata,
1020 "Mesh plink: can't establish link with secure peer\n");
1021 return;
1022 }
1023
1024 ftype = mgmt->u.action.u.self_prot.action_code;
1025 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
1026 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
1027 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
1028 && ie_len != 8)) {
1029 mpl_dbg(sdata,
1030 "Mesh plink: incorrect plink ie length %d %d\n",
1031 ftype, ie_len);
1032 return;
1033 }
1034
1035 if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
1036 (!elems->mesh_id || !elems->mesh_config)) {
1037 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
1038 return;
1039 }
1040 /* Note the lines below are correct, the llid in the frame is the plid
1041 * from the point of view of this host.
1042 */
1043 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering));
1044 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
1045 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
1046 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering));
1047
1048 /* WARNING: Only for sta pointer, is dropped & re-acquired */
1049 rcu_read_lock();
1050
1051 sta = sta_info_get(sdata, mgmt->sa);
1052
1053 if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
1054 !rssi_threshold_check(sdata, sta)) {
1055 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
1056 mgmt->sa);
1057 goto unlock_rcu;
1058 }
1059
1060 /* Now we will figure out the appropriate event... */
1061 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid);
1062
1063 if (event == OPN_ACPT) {
1064 rcu_read_unlock();
1065 /* allocate sta entry if necessary and update info */
1066 sta = mesh_sta_info_get(sdata, mgmt->sa, elems);
1067 if (!sta) {
1068 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
1069 goto unlock_rcu;
1070 }
1071 sta->plid = plid;
1072 } else if (!sta && event == OPN_RJCT) {
1073 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
1074 mgmt->sa, 0, plid,
1075 WLAN_REASON_MESH_CONFIG);
1076 goto unlock_rcu;
1077 } else if (!sta || event == PLINK_UNDEFINED) {
1078 /* something went wrong */
1079 goto unlock_rcu;
1080 }
1081
1082 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */
1083 if (!sta->plid && event == CNF_ACPT)
1084 sta->plid = plid;
1085
1086 changed |= mesh_plink_fsm(sdata, sta, event);
1087
1088 unlock_rcu:
1089 rcu_read_unlock();
1090
1091 if (changed)
1092 ieee80211_mbss_info_change_notify(sdata, changed);
1093 }
1094
1095 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
1096 struct ieee80211_mgmt *mgmt, size_t len,
1097 struct ieee80211_rx_status *rx_status)
1098 {
1099 struct ieee802_11_elems elems;
1100 size_t baselen;
1101 u8 *baseaddr;
1102
1103 /* need action_code, aux */
1104 if (len < IEEE80211_MIN_ACTION_SIZE + 3)
1105 return;
1106
1107 if (sdata->u.mesh.user_mpm)
1108 /* userspace must register for these */
1109 return;
1110
1111 if (is_multicast_ether_addr(mgmt->da)) {
1112 mpl_dbg(sdata,
1113 "Mesh plink: ignore frame from multicast address\n");
1114 return;
1115 }
1116
1117 baseaddr = mgmt->u.action.u.self_prot.variable;
1118 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
1119 if (mgmt->u.action.u.self_prot.action_code ==
1120 WLAN_SP_MESH_PEERING_CONFIRM) {
1121 baseaddr += 4;
1122 baselen += 4;
1123 }
1124 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems);
1125 mesh_process_plink_frame(sdata, mgmt, &elems);
1126 }
Linux with added FPC-III support