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netlink, mmap: fix edge-case leakages in nf queue zero-copy
[linux-2.6/btrfs-unstable.git] / net / mac80211 / mesh_plink.c
blob58384642e03c52bb6427fc809a9149769855e9c1
1 /*
2 * Copyright (c) 2008, 2009 open80211s Ltd.
3 * Author: Luis Carlos Cobo <luisca@cozybit.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9 #include <linux/gfp.h>
10 #include <linux/kernel.h>
11 #include <linux/random.h>
12 #include "ieee80211_i.h"
13 #include "rate.h"
14 #include "mesh.h"
15
16 #define PLINK_CNF_AID(mgmt) ((mgmt)->u.action.u.self_prot.variable + 2)
17 #define PLINK_GET_LLID(p) (p + 2)
18 #define PLINK_GET_PLID(p) (p + 4)
19
20 #define mod_plink_timer(s, t) (mod_timer(&s->mesh->plink_timer, \
21 jiffies + msecs_to_jiffies(t)))
22
23 enum plink_event {
24 PLINK_UNDEFINED,
25 OPN_ACPT,
26 OPN_RJCT,
27 OPN_IGNR,
28 CNF_ACPT,
29 CNF_RJCT,
30 CNF_IGNR,
31 CLS_ACPT,
32 CLS_IGNR
33 };
34
35 static const char * const mplstates[] = {
36 [NL80211_PLINK_LISTEN] = "LISTEN",
37 [NL80211_PLINK_OPN_SNT] = "OPN-SNT",
38 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
39 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
40 [NL80211_PLINK_ESTAB] = "ESTAB",
41 [NL80211_PLINK_HOLDING] = "HOLDING",
42 [NL80211_PLINK_BLOCKED] = "BLOCKED"
43 };
44
45 static const char * const mplevents[] = {
46 [PLINK_UNDEFINED] = "NONE",
47 [OPN_ACPT] = "OPN_ACPT",
48 [OPN_RJCT] = "OPN_RJCT",
49 [OPN_IGNR] = "OPN_IGNR",
50 [CNF_ACPT] = "CNF_ACPT",
51 [CNF_RJCT] = "CNF_RJCT",
52 [CNF_IGNR] = "CNF_IGNR",
53 [CLS_ACPT] = "CLS_ACPT",
54 [CLS_IGNR] = "CLS_IGNR"
55 };
56
57 /* We only need a valid sta if user configured a minimum rssi_threshold. */
58 static bool rssi_threshold_check(struct ieee80211_sub_if_data *sdata,
59 struct sta_info *sta)
60 {
61 s32 rssi_threshold = sdata->u.mesh.mshcfg.rssi_threshold;
62 return rssi_threshold == 0 ||
63 (sta && (s8) -ewma_signal_read(&sta->avg_signal) > rssi_threshold);
64 }
65
66 /**
67 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
68 *
69 * @sta: mesh peer link to restart
70 *
71 * Locking: this function must be called holding sta->mesh->plink_lock
72 */
73 static inline void mesh_plink_fsm_restart(struct sta_info *sta)
74 {
75 lockdep_assert_held(&sta->mesh->plink_lock);
76 sta->mesh->plink_state = NL80211_PLINK_LISTEN;
77 sta->mesh->llid = sta->mesh->plid = sta->mesh->reason = 0;
78 sta->mesh->plink_retries = 0;
79 }
80
81 /*
82 * mesh_set_short_slot_time - enable / disable ERP short slot time.
83 *
84 * The standard indirectly mandates mesh STAs to turn off short slot time by
85 * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we
86 * can't be sneaky about it. Enable short slot time if all mesh STAs in the
87 * MBSS support ERP rates.
88 *
89 * Returns BSS_CHANGED_ERP_SLOT or 0 for no change.
90 */
91 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata)
92 {
93 struct ieee80211_local *local = sdata->local;
94 enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
95 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
96 struct sta_info *sta;
97 u32 erp_rates = 0, changed = 0;
98 int i;
99 bool short_slot = false;
100
101 if (band == IEEE80211_BAND_5GHZ) {
102 /* (IEEE 802.11-2012 19.4.5) */
103 short_slot = true;
104 goto out;
105 } else if (band != IEEE80211_BAND_2GHZ)
106 goto out;
107
108 for (i = 0; i < sband->n_bitrates; i++)
109 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)
110 erp_rates |= BIT(i);
111
112 if (!erp_rates)
113 goto out;
114
115 rcu_read_lock();
116 list_for_each_entry_rcu(sta, &local->sta_list, list) {
117 if (sdata != sta->sdata ||
118 sta->mesh->plink_state != NL80211_PLINK_ESTAB)
119 continue;
120
121 short_slot = false;
122 if (erp_rates & sta->sta.supp_rates[band])
123 short_slot = true;
124 else
125 break;
126 }
127 rcu_read_unlock();
128
129 out:
130 if (sdata->vif.bss_conf.use_short_slot != short_slot) {
131 sdata->vif.bss_conf.use_short_slot = short_slot;
132 changed = BSS_CHANGED_ERP_SLOT;
133 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n",
134 sdata->vif.addr, short_slot);
135 }
136 return changed;
137 }
138
139 /**
140 * mesh_set_ht_prot_mode - set correct HT protection mode
141 *
142 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
143 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
144 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
145 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode
146 * is selected if all peers in our 20/40MHz MBSS support HT and atleast one
147 * HT20 peer is present. Otherwise no-protection mode is selected.
148 */
149 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
150 {
151 struct ieee80211_local *local = sdata->local;
152 struct sta_info *sta;
153 u16 ht_opmode;
154 bool non_ht_sta = false, ht20_sta = false;
155
156 switch (sdata->vif.bss_conf.chandef.width) {
157 case NL80211_CHAN_WIDTH_20_NOHT:
158 case NL80211_CHAN_WIDTH_5:
159 case NL80211_CHAN_WIDTH_10:
160 return 0;
161 default:
162 break;
163 }
164
165 rcu_read_lock();
166 list_for_each_entry_rcu(sta, &local->sta_list, list) {
167 if (sdata != sta->sdata ||
168 sta->mesh->plink_state != NL80211_PLINK_ESTAB)
169 continue;
170
171 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20)
172 continue;
173
174 if (!sta->sta.ht_cap.ht_supported) {
175 mpl_dbg(sdata, "nonHT sta (%pM) is present\n",
176 sta->sta.addr);
177 non_ht_sta = true;
178 break;
179 }
180
181 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr);
182 ht20_sta = true;
183 }
184 rcu_read_unlock();
185
186 if (non_ht_sta)
187 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
188 else if (ht20_sta &&
189 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20)
190 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
191 else
192 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
193
194 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode)
195 return 0;
196
197 sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
198 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
199 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode);
200 return BSS_CHANGED_HT;
201 }
202
203 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
204 struct sta_info *sta,
205 enum ieee80211_self_protected_actioncode action,
206 u8 *da, u16 llid, u16 plid, u16 reason)
207 {
208 struct ieee80211_local *local = sdata->local;
209 struct sk_buff *skb;
210 struct ieee80211_tx_info *info;
211 struct ieee80211_mgmt *mgmt;
212 bool include_plid = false;
213 u16 peering_proto = 0;
214 u8 *pos, ie_len = 4;
215 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) +
216 sizeof(mgmt->u.action.u.self_prot);
217 int err = -ENOMEM;
218
219 skb = dev_alloc_skb(local->tx_headroom +
220 hdr_len +
221 2 + /* capability info */
222 2 + /* AID */
223 2 + 8 + /* supported rates */
224 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
225 2 + sdata->u.mesh.mesh_id_len +
226 2 + sizeof(struct ieee80211_meshconf_ie) +
227 2 + sizeof(struct ieee80211_ht_cap) +
228 2 + sizeof(struct ieee80211_ht_operation) +
229 2 + 8 + /* peering IE */
230 sdata->u.mesh.ie_len);
231 if (!skb)
232 return err;
233 info = IEEE80211_SKB_CB(skb);
234 skb_reserve(skb, local->tx_headroom);
235 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
236 memset(mgmt, 0, hdr_len);
237 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
238 IEEE80211_STYPE_ACTION);
239 memcpy(mgmt->da, da, ETH_ALEN);
240 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
241 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
242 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
243 mgmt->u.action.u.self_prot.action_code = action;
244
245 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
246 enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
247
248 /* capability info */
249 pos = skb_put(skb, 2);
250 memset(pos, 0, 2);
251 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
252 /* AID */
253 pos = skb_put(skb, 2);
254 put_unaligned_le16(sta->sta.aid, pos);
255 }
256 if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
257 ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
258 mesh_add_rsn_ie(sdata, skb) ||
259 mesh_add_meshid_ie(sdata, skb) ||
260 mesh_add_meshconf_ie(sdata, skb))
261 goto free;
262 } else { /* WLAN_SP_MESH_PEERING_CLOSE */
263 info->flags |= IEEE80211_TX_CTL_NO_ACK;
264 if (mesh_add_meshid_ie(sdata, skb))
265 goto free;
266 }
267
268 /* Add Mesh Peering Management element */
269 switch (action) {
270 case WLAN_SP_MESH_PEERING_OPEN:
271 break;
272 case WLAN_SP_MESH_PEERING_CONFIRM:
273 ie_len += 2;
274 include_plid = true;
275 break;
276 case WLAN_SP_MESH_PEERING_CLOSE:
277 if (plid) {
278 ie_len += 2;
279 include_plid = true;
280 }
281 ie_len += 2; /* reason code */
282 break;
283 default:
284 err = -EINVAL;
285 goto free;
286 }
287
288 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
289 goto free;
290
291 pos = skb_put(skb, 2 + ie_len);
292 *pos++ = WLAN_EID_PEER_MGMT;
293 *pos++ = ie_len;
294 memcpy(pos, &peering_proto, 2);
295 pos += 2;
296 put_unaligned_le16(llid, pos);
297 pos += 2;
298 if (include_plid) {
299 put_unaligned_le16(plid, pos);
300 pos += 2;
301 }
302 if (action == WLAN_SP_MESH_PEERING_CLOSE) {
303 put_unaligned_le16(reason, pos);
304 pos += 2;
305 }
306
307 if (action != WLAN_SP_MESH_PEERING_CLOSE) {
308 if (mesh_add_ht_cap_ie(sdata, skb) ||
309 mesh_add_ht_oper_ie(sdata, skb))
310 goto free;
311 }
312
313 if (mesh_add_vendor_ies(sdata, skb))
314 goto free;
315
316 ieee80211_tx_skb(sdata, skb);
317 return 0;
318 free:
319 kfree_skb(skb);
320 return err;
321 }
322
323 /**
324 * __mesh_plink_deactivate - deactivate mesh peer link
325 *
326 * @sta: mesh peer link to deactivate
327 *
328 * All mesh paths with this peer as next hop will be flushed
329 * Returns beacon changed flag if the beacon content changed.
330 *
331 * Locking: the caller must hold sta->mesh->plink_lock
332 */
333 static u32 __mesh_plink_deactivate(struct sta_info *sta)
334 {
335 struct ieee80211_sub_if_data *sdata = sta->sdata;
336 u32 changed = 0;
337
338 lockdep_assert_held(&sta->mesh->plink_lock);
339
340 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
341 changed = mesh_plink_dec_estab_count(sdata);
342 sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
343 mesh_path_flush_by_nexthop(sta);
344
345 ieee80211_mps_sta_status_update(sta);
346 changed |= ieee80211_mps_set_sta_local_pm(sta,
347 NL80211_MESH_POWER_UNKNOWN);
348
349 return changed;
350 }
351
352 /**
353 * mesh_plink_deactivate - deactivate mesh peer link
354 *
355 * @sta: mesh peer link to deactivate
356 *
357 * All mesh paths with this peer as next hop will be flushed
358 */
359 u32 mesh_plink_deactivate(struct sta_info *sta)
360 {
361 struct ieee80211_sub_if_data *sdata = sta->sdata;
362 u32 changed;
363
364 spin_lock_bh(&sta->mesh->plink_lock);
365 changed = __mesh_plink_deactivate(sta);
366 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED;
367 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE,
368 sta->sta.addr, sta->mesh->llid, sta->mesh->plid,
369 sta->mesh->reason);
370 spin_unlock_bh(&sta->mesh->plink_lock);
371
372 return changed;
373 }
374
375 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
376 struct sta_info *sta,
377 struct ieee802_11_elems *elems, bool insert)
378 {
379 struct ieee80211_local *local = sdata->local;
380 enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
381 struct ieee80211_supported_band *sband;
382 u32 rates, basic_rates = 0, changed = 0;
383 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth;
384
385 sband = local->hw.wiphy->bands[band];
386 rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates);
387
388 spin_lock_bh(&sta->mesh->plink_lock);
389 sta->last_rx = jiffies;
390
391 /* rates and capabilities don't change during peering */
392 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB &&
393 sta->mesh->processed_beacon)
394 goto out;
395 sta->mesh->processed_beacon = true;
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->mesh->plink_lock);
423 }
424
425 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata)
426 {
427 struct sta_info *sta;
428 unsigned long *aid_map;
429 int aid;
430
431 aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1),
432 sizeof(*aid_map), GFP_KERNEL);
433 if (!aid_map)
434 return -ENOMEM;
435
436 /* reserve aid 0 for mcast indication */
437 __set_bit(0, aid_map);
438
439 rcu_read_lock();
440 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list)
441 __set_bit(sta->sta.aid, aid_map);
442 rcu_read_unlock();
443
444 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1);
445 kfree(aid_map);
446
447 if (aid > IEEE80211_MAX_AID)
448 return -ENOBUFS;
449
450 return aid;
451 }
452
453 static struct sta_info *
454 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
455 {
456 struct sta_info *sta;
457 int aid;
458
459 if (sdata->local->num_sta >= MESH_MAX_PLINKS)
460 return NULL;
461
462 aid = mesh_allocate_aid(sdata);
463 if (aid < 0)
464 return NULL;
465
466 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
467 if (!sta)
468 return NULL;
469
470 sta->mesh->plink_state = NL80211_PLINK_LISTEN;
471 sta->sta.wme = true;
472 sta->sta.aid = aid;
473
474 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
475 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
476 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
477
478 return sta;
479 }
480
481 static struct sta_info *
482 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
483 struct ieee802_11_elems *elems)
484 {
485 struct sta_info *sta = NULL;
486
487 /* Userspace handles station allocation */
488 if (sdata->u.mesh.user_mpm ||
489 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED)
490 cfg80211_notify_new_peer_candidate(sdata->dev, addr,
491 elems->ie_start,
492 elems->total_len,
493 GFP_KERNEL);
494 else
495 sta = __mesh_sta_info_alloc(sdata, addr);
496
497 return sta;
498 }
499
500 /*
501 * mesh_sta_info_get - return mesh sta info entry for @addr.
502 *
503 * @sdata: local meshif
504 * @addr: peer's address
505 * @elems: IEs from beacon or mesh peering frame.
506 *
507 * Return existing or newly allocated sta_info under RCU read lock.
508 * (re)initialize with given IEs.
509 */
510 static struct sta_info *
511 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
512 u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU)
513 {
514 struct sta_info *sta = NULL;
515
516 rcu_read_lock();
517 sta = sta_info_get(sdata, addr);
518 if (sta) {
519 mesh_sta_info_init(sdata, sta, elems, false);
520 } else {
521 rcu_read_unlock();
522 /* can't run atomic */
523 sta = mesh_sta_info_alloc(sdata, addr, elems);
524 if (!sta) {
525 rcu_read_lock();
526 return NULL;
527 }
528
529 mesh_sta_info_init(sdata, sta, elems, true);
530
531 if (sta_info_insert_rcu(sta))
532 return NULL;
533 }
534
535 return sta;
536 }
537
538 /*
539 * mesh_neighbour_update - update or initialize new mesh neighbor.
540 *
541 * @sdata: local meshif
542 * @addr: peer's address
543 * @elems: IEs from beacon or mesh peering frame
544 *
545 * Initiates peering if appropriate.
546 */
547 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
548 u8 *hw_addr,
549 struct ieee802_11_elems *elems)
550 {
551 struct sta_info *sta;
552 u32 changed = 0;
553
554 sta = mesh_sta_info_get(sdata, hw_addr, elems);
555 if (!sta)
556 goto out;
557
558 if (mesh_peer_accepts_plinks(elems) &&
559 sta->mesh->plink_state == NL80211_PLINK_LISTEN &&
560 sdata->u.mesh.accepting_plinks &&
561 sdata->u.mesh.mshcfg.auto_open_plinks &&
562 rssi_threshold_check(sdata, sta))
563 changed = mesh_plink_open(sta);
564
565 ieee80211_mps_frame_release(sta, elems);
566 out:
567 rcu_read_unlock();
568 ieee80211_mbss_info_change_notify(sdata, changed);
569 }
570
571 static void mesh_plink_timer(unsigned long data)
572 {
573 struct sta_info *sta;
574 u16 reason = 0;
575 struct ieee80211_sub_if_data *sdata;
576 struct mesh_config *mshcfg;
577 enum ieee80211_self_protected_actioncode action = 0;
578
579 /*
580 * This STA is valid because sta_info_destroy() will
581 * del_timer_sync() this timer after having made sure
582 * it cannot be readded (by deleting the plink.)
583 */
584 sta = (struct sta_info *) data;
585
586 if (sta->sdata->local->quiescing)
587 return;
588
589 spin_lock_bh(&sta->mesh->plink_lock);
590
591 /* If a timer fires just before a state transition on another CPU,
592 * we may have already extended the timeout and changed state by the
593 * time we've acquired the lock and arrived here. In that case,
594 * skip this timer and wait for the new one.
595 */
596 if (time_before(jiffies, sta->mesh->plink_timer.expires)) {
597 mpl_dbg(sta->sdata,
598 "Ignoring timer for %pM in state %s (timer adjusted)",
599 sta->sta.addr, mplstates[sta->mesh->plink_state]);
600 spin_unlock_bh(&sta->mesh->plink_lock);
601 return;
602 }
603
604 /* del_timer() and handler may race when entering these states */
605 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN ||
606 sta->mesh->plink_state == NL80211_PLINK_ESTAB) {
607 mpl_dbg(sta->sdata,
608 "Ignoring timer for %pM in state %s (timer deleted)",
609 sta->sta.addr, mplstates[sta->mesh->plink_state]);
610 spin_unlock_bh(&sta->mesh->plink_lock);
611 return;
612 }
613
614 mpl_dbg(sta->sdata,
615 "Mesh plink timer for %pM fired on state %s\n",
616 sta->sta.addr, mplstates[sta->mesh->plink_state]);
617 sdata = sta->sdata;
618 mshcfg = &sdata->u.mesh.mshcfg;
619
620 switch (sta->mesh->plink_state) {
621 case NL80211_PLINK_OPN_RCVD:
622 case NL80211_PLINK_OPN_SNT:
623 /* retry timer */
624 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) {
625 u32 rand;
626 mpl_dbg(sta->sdata,
627 "Mesh plink for %pM (retry, timeout): %d %d\n",
628 sta->sta.addr, sta->mesh->plink_retries,
629 sta->mesh->plink_timeout);
630 get_random_bytes(&rand, sizeof(u32));
631 sta->mesh->plink_timeout = sta->mesh->plink_timeout +
632 rand % sta->mesh->plink_timeout;
633 ++sta->mesh->plink_retries;
634 mod_plink_timer(sta, sta->mesh->plink_timeout);
635 action = WLAN_SP_MESH_PEERING_OPEN;
636 break;
637 }
638 reason = WLAN_REASON_MESH_MAX_RETRIES;
639 /* fall through on else */
640 case NL80211_PLINK_CNF_RCVD:
641 /* confirm timer */
642 if (!reason)
643 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT;
644 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
645 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
646 action = WLAN_SP_MESH_PEERING_CLOSE;
647 break;
648 case NL80211_PLINK_HOLDING:
649 /* holding timer */
650 del_timer(&sta->mesh->plink_timer);
651 mesh_plink_fsm_restart(sta);
652 break;
653 default:
654 break;
655 }
656 spin_unlock_bh(&sta->mesh->plink_lock);
657 if (action)
658 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
659 sta->mesh->llid, sta->mesh->plid, reason);
660 }
661
662 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout)
663 {
664 sta->mesh->plink_timer.expires = jiffies + msecs_to_jiffies(timeout);
665 sta->mesh->plink_timer.data = (unsigned long) sta;
666 sta->mesh->plink_timer.function = mesh_plink_timer;
667 sta->mesh->plink_timeout = timeout;
668 add_timer(&sta->mesh->plink_timer);
669 }
670
671 static bool llid_in_use(struct ieee80211_sub_if_data *sdata,
672 u16 llid)
673 {
674 struct ieee80211_local *local = sdata->local;
675 bool in_use = false;
676 struct sta_info *sta;
677
678 rcu_read_lock();
679 list_for_each_entry_rcu(sta, &local->sta_list, list) {
680 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) {
681 in_use = true;
682 break;
683 }
684 }
685 rcu_read_unlock();
686
687 return in_use;
688 }
689
690 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata)
691 {
692 u16 llid;
693
694 do {
695 get_random_bytes(&llid, sizeof(llid));
696 } while (llid_in_use(sdata, llid));
697
698 return llid;
699 }
700
701 u32 mesh_plink_open(struct sta_info *sta)
702 {
703 struct ieee80211_sub_if_data *sdata = sta->sdata;
704 u32 changed;
705
706 if (!test_sta_flag(sta, WLAN_STA_AUTH))
707 return 0;
708
709 spin_lock_bh(&sta->mesh->plink_lock);
710 sta->mesh->llid = mesh_get_new_llid(sdata);
711 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN &&
712 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) {
713 spin_unlock_bh(&sta->mesh->plink_lock);
714 return 0;
715 }
716 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT;
717 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
718 spin_unlock_bh(&sta->mesh->plink_lock);
719 mpl_dbg(sdata,
720 "Mesh plink: starting establishment with %pM\n",
721 sta->sta.addr);
722
723 /* set the non-peer mode to active during peering */
724 changed = ieee80211_mps_local_status_update(sdata);
725
726 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN,
727 sta->sta.addr, sta->mesh->llid, 0, 0);
728 return changed;
729 }
730
731 u32 mesh_plink_block(struct sta_info *sta)
732 {
733 u32 changed;
734
735 spin_lock_bh(&sta->mesh->plink_lock);
736 changed = __mesh_plink_deactivate(sta);
737 sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
738 spin_unlock_bh(&sta->mesh->plink_lock);
739
740 return changed;
741 }
742
743 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata,
744 struct sta_info *sta,
745 enum plink_event event)
746 {
747 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
748 u16 reason = (event == CLS_ACPT) ?
749 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG;
750
751 sta->mesh->reason = reason;
752 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
753 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
754 }
755
756 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata,
757 struct sta_info *sta)
758 {
759 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
760 u32 changed = 0;
761
762 del_timer(&sta->mesh->plink_timer);
763 sta->mesh->plink_state = NL80211_PLINK_ESTAB;
764 changed |= mesh_plink_inc_estab_count(sdata);
765 changed |= mesh_set_ht_prot_mode(sdata);
766 changed |= mesh_set_short_slot_time(sdata);
767 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr);
768 ieee80211_mps_sta_status_update(sta);
769 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode);
770 return changed;
771 }
772
773 /**
774 * mesh_plink_fsm - step @sta MPM based on @event
775 *
776 * @sdata: interface
777 * @sta: mesh neighbor
778 * @event: peering event
779 *
780 * Return: changed MBSS flags
781 */
782 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata,
783 struct sta_info *sta, enum plink_event event)
784 {
785 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
786 enum ieee80211_self_protected_actioncode action = 0;
787 u32 changed = 0;
788
789 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr,
790 mplstates[sta->mesh->plink_state], mplevents[event]);
791
792 spin_lock_bh(&sta->mesh->plink_lock);
793 switch (sta->mesh->plink_state) {
794 case NL80211_PLINK_LISTEN:
795 switch (event) {
796 case CLS_ACPT:
797 mesh_plink_fsm_restart(sta);
798 break;
799 case OPN_ACPT:
800 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
801 sta->mesh->llid = mesh_get_new_llid(sdata);
802 mesh_plink_timer_set(sta,
803 mshcfg->dot11MeshRetryTimeout);
804
805 /* set the non-peer mode to active during peering */
806 changed |= ieee80211_mps_local_status_update(sdata);
807 action = WLAN_SP_MESH_PEERING_OPEN;
808 break;
809 default:
810 break;
811 }
812 break;
813 case NL80211_PLINK_OPN_SNT:
814 switch (event) {
815 case OPN_RJCT:
816 case CNF_RJCT:
817 case CLS_ACPT:
818 mesh_plink_close(sdata, sta, event);
819 action = WLAN_SP_MESH_PEERING_CLOSE;
820 break;
821 case OPN_ACPT:
822 /* retry timer is left untouched */
823 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
824 action = WLAN_SP_MESH_PEERING_CONFIRM;
825 break;
826 case CNF_ACPT:
827 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD;
828 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout);
829 break;
830 default:
831 break;
832 }
833 break;
834 case NL80211_PLINK_OPN_RCVD:
835 switch (event) {
836 case OPN_RJCT:
837 case CNF_RJCT:
838 case CLS_ACPT:
839 mesh_plink_close(sdata, sta, event);
840 action = WLAN_SP_MESH_PEERING_CLOSE;
841 break;
842 case OPN_ACPT:
843 action = WLAN_SP_MESH_PEERING_CONFIRM;
844 break;
845 case CNF_ACPT:
846 changed |= mesh_plink_establish(sdata, sta);
847 break;
848 default:
849 break;
850 }
851 break;
852 case NL80211_PLINK_CNF_RCVD:
853 switch (event) {
854 case OPN_RJCT:
855 case CNF_RJCT:
856 case CLS_ACPT:
857 mesh_plink_close(sdata, sta, event);
858 action = WLAN_SP_MESH_PEERING_CLOSE;
859 break;
860 case OPN_ACPT:
861 changed |= mesh_plink_establish(sdata, sta);
862 action = WLAN_SP_MESH_PEERING_CONFIRM;
863 break;
864 default:
865 break;
866 }
867 break;
868 case NL80211_PLINK_ESTAB:
869 switch (event) {
870 case CLS_ACPT:
871 changed |= __mesh_plink_deactivate(sta);
872 changed |= mesh_set_ht_prot_mode(sdata);
873 changed |= mesh_set_short_slot_time(sdata);
874 mesh_plink_close(sdata, sta, event);
875 action = WLAN_SP_MESH_PEERING_CLOSE;
876 break;
877 case OPN_ACPT:
878 action = WLAN_SP_MESH_PEERING_CONFIRM;
879 break;
880 default:
881 break;
882 }
883 break;
884 case NL80211_PLINK_HOLDING:
885 switch (event) {
886 case CLS_ACPT:
887 del_timer(&sta->mesh->plink_timer);
888 mesh_plink_fsm_restart(sta);
889 break;
890 case OPN_ACPT:
891 case CNF_ACPT:
892 case OPN_RJCT:
893 case CNF_RJCT:
894 action = WLAN_SP_MESH_PEERING_CLOSE;
895 break;
896 default:
897 break;
898 }
899 break;
900 default:
901 /* should not get here, PLINK_BLOCKED is dealt with at the
902 * beginning of the function
903 */
904 break;
905 }
906 spin_unlock_bh(&sta->mesh->plink_lock);
907 if (action) {
908 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
909 sta->mesh->llid, sta->mesh->plid,
910 sta->mesh->reason);
911
912 /* also send confirm in open case */
913 if (action == WLAN_SP_MESH_PEERING_OPEN) {
914 mesh_plink_frame_tx(sdata, sta,
915 WLAN_SP_MESH_PEERING_CONFIRM,
916 sta->sta.addr, sta->mesh->llid,
917 sta->mesh->plid, 0);
918 }
919 }
920
921 return changed;
922 }
923
924 /*
925 * mesh_plink_get_event - get correct MPM event
926 *
927 * @sdata: interface
928 * @sta: peer, leave NULL if processing a frame from a new suitable peer
929 * @elems: peering management IEs
930 * @ftype: frame type
931 * @llid: peer's peer link ID
932 * @plid: peer's local link ID
933 *
934 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as
935 * an error.
936 */
937 static enum plink_event
938 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata,
939 struct sta_info *sta,
940 struct ieee802_11_elems *elems,
941 enum ieee80211_self_protected_actioncode ftype,
942 u16 llid, u16 plid)
943 {
944 enum plink_event event = PLINK_UNDEFINED;
945 u8 ie_len = elems->peering_len;
946 bool matches_local;
947
948 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE ||
949 mesh_matches_local(sdata, elems));
950
951 /* deny open request from non-matching peer */
952 if (!matches_local && !sta) {
953 event = OPN_RJCT;
954 goto out;
955 }
956
957 if (!sta) {
958 if (ftype != WLAN_SP_MESH_PEERING_OPEN) {
959 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
960 goto out;
961 }
962 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
963 if (!mesh_plink_free_count(sdata)) {
964 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
965 goto out;
966 }
967 } else {
968 if (!test_sta_flag(sta, WLAN_STA_AUTH)) {
969 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
970 goto out;
971 }
972 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED)
973 goto out;
974 }
975
976 /* new matching peer */
977 if (!sta) {
978 event = OPN_ACPT;
979 goto out;
980 }
981
982 switch (ftype) {
983 case WLAN_SP_MESH_PEERING_OPEN:
984 if (!matches_local)
985 event = OPN_RJCT;
986 if (!mesh_plink_free_count(sdata) ||
987 (sta->mesh->plid && sta->mesh->plid != plid))
988 event = OPN_IGNR;
989 else
990 event = OPN_ACPT;
991 break;
992 case WLAN_SP_MESH_PEERING_CONFIRM:
993 if (!matches_local)
994 event = CNF_RJCT;
995 if (!mesh_plink_free_count(sdata) ||
996 sta->mesh->llid != llid ||
997 (sta->mesh->plid && sta->mesh->plid != plid))
998 event = CNF_IGNR;
999 else
1000 event = CNF_ACPT;
1001 break;
1002 case WLAN_SP_MESH_PEERING_CLOSE:
1003 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
1004 /* Do not check for llid or plid. This does not
1005 * follow the standard but since multiple plinks
1006 * per sta are not supported, it is necessary in
1007 * order to avoid a livelock when MP A sees an
1008 * establish peer link to MP B but MP B does not
1009 * see it. This can be caused by a timeout in
1010 * B's peer link establishment or B beign
1011 * restarted.
1012 */
1013 event = CLS_ACPT;
1014 else if (sta->mesh->plid != plid)
1015 event = CLS_IGNR;
1016 else if (ie_len == 8 && sta->mesh->llid != llid)
1017 event = CLS_IGNR;
1018 else
1019 event = CLS_ACPT;
1020 break;
1021 default:
1022 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
1023 break;
1024 }
1025
1026 out:
1027 return event;
1028 }
1029
1030 static void
1031 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
1032 struct ieee80211_mgmt *mgmt,
1033 struct ieee802_11_elems *elems)
1034 {
1035
1036 struct sta_info *sta;
1037 enum plink_event event;
1038 enum ieee80211_self_protected_actioncode ftype;
1039 u32 changed = 0;
1040 u8 ie_len = elems->peering_len;
1041 u16 plid, llid = 0;
1042
1043 if (!elems->peering) {
1044 mpl_dbg(sdata,
1045 "Mesh plink: missing necessary peer link ie\n");
1046 return;
1047 }
1048
1049 if (elems->rsn_len &&
1050 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
1051 mpl_dbg(sdata,
1052 "Mesh plink: can't establish link with secure peer\n");
1053 return;
1054 }
1055
1056 ftype = mgmt->u.action.u.self_prot.action_code;
1057 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
1058 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
1059 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
1060 && ie_len != 8)) {
1061 mpl_dbg(sdata,
1062 "Mesh plink: incorrect plink ie length %d %d\n",
1063 ftype, ie_len);
1064 return;
1065 }
1066
1067 if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
1068 (!elems->mesh_id || !elems->mesh_config)) {
1069 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
1070 return;
1071 }
1072 /* Note the lines below are correct, the llid in the frame is the plid
1073 * from the point of view of this host.
1074 */
1075 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering));
1076 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
1077 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
1078 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering));
1079
1080 /* WARNING: Only for sta pointer, is dropped & re-acquired */
1081 rcu_read_lock();
1082
1083 sta = sta_info_get(sdata, mgmt->sa);
1084
1085 if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
1086 !rssi_threshold_check(sdata, sta)) {
1087 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
1088 mgmt->sa);
1089 goto unlock_rcu;
1090 }
1091
1092 /* Now we will figure out the appropriate event... */
1093 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid);
1094
1095 if (event == OPN_ACPT) {
1096 rcu_read_unlock();
1097 /* allocate sta entry if necessary and update info */
1098 sta = mesh_sta_info_get(sdata, mgmt->sa, elems);
1099 if (!sta) {
1100 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
1101 goto unlock_rcu;
1102 }
1103 sta->mesh->plid = plid;
1104 } else if (!sta && event == OPN_RJCT) {
1105 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE,
1106 mgmt->sa, 0, plid,
1107 WLAN_REASON_MESH_CONFIG);
1108 goto unlock_rcu;
1109 } else if (!sta || event == PLINK_UNDEFINED) {
1110 /* something went wrong */
1111 goto unlock_rcu;
1112 }
1113
1114 if (event == CNF_ACPT) {
1115 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */
1116 if (!sta->mesh->plid)
1117 sta->mesh->plid = plid;
1118
1119 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt));
1120 }
1121
1122 changed |= mesh_plink_fsm(sdata, sta, event);
1123
1124 unlock_rcu:
1125 rcu_read_unlock();
1126
1127 if (changed)
1128 ieee80211_mbss_info_change_notify(sdata, changed);
1129 }
1130
1131 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
1132 struct ieee80211_mgmt *mgmt, size_t len,
1133 struct ieee80211_rx_status *rx_status)
1134 {
1135 struct ieee802_11_elems elems;
1136 size_t baselen;
1137 u8 *baseaddr;
1138
1139 /* need action_code, aux */
1140 if (len < IEEE80211_MIN_ACTION_SIZE + 3)
1141 return;
1142
1143 if (sdata->u.mesh.user_mpm)
1144 /* userspace must register for these */
1145 return;
1146
1147 if (is_multicast_ether_addr(mgmt->da)) {
1148 mpl_dbg(sdata,
1149 "Mesh plink: ignore frame from multicast address\n");
1150 return;
1151 }
1152
1153 baseaddr = mgmt->u.action.u.self_prot.variable;
1154 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
1155 if (mgmt->u.action.u.self_prot.action_code ==
1156 WLAN_SP_MESH_PEERING_CONFIRM) {
1157 baseaddr += 4;
1158 baselen += 4;
1159
1160 if (baselen > len)
1161 return;
1162 }
1163 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems);
1164 mesh_process_plink_frame(sdata, mgmt, &elems);
1165 }
(deprecated) Btrfs devel tree